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whelen
07-30-2005, 08:19 PM
High speed spindles are complicated and pricy, as I've learned. KDN Tool & Automation Engineering will provide a belt drive for my MicroMark MicroLux #82710. KDN Tool & Automation (www.kdntool.com) is in the process of converting my mill to full CNC. The SIEG X2 can get up to 2,500 rpm with the stock gear drive. KDN Tool & Automation has an option, to belt drive the spindle, getting it up to 4,000 rpm. Going higher is not recommended.

I am not recommending that anyone do what follows!!! I'm only brainstorming.
You could purchase a Proxxon Micro Mill MF 70, from Tool-Switch for $300 + shipping and taxes. The Proxxon motor and spindle assembly, turns from 5,000 to 20,000 rpm. Proxxon is a quality made machine. The application for the MF 70 is "Small precision mill for lab, optician, jewelry, electronic, and model projects". I want to engrave. The maximum power is 100watts. So lets see if the Proxxon motor and spindle assembly can be adapted for engraving. Back of the envelope scoping calculations. I worked as an advanced development engineer up to 20 years ago. I switched to planning, marketing, and sales management - it paid a lot better. So I'm rusty on my Manufacturing Engineering (did that before becoming a Mechanical Engineer) -please feel free to correct me in my calculations.

Torque (N-m)=depth of cut (mm) X width of cut (mm) X feed rate (mm per tooth) X number of teeth X machineability factor (0.145 for aluminum, 0.435 for steel)
depth of cut (mm) 1 mm 0.039 in
width of cut (mm) 1 mm
feed rate (mm per tooth) 0.18 mm/tooth high speed steel cutter, on brass
number of teeth 2 a pointed engraving cutter
machineability factor 0.29 half way between aluminum and steel

Torque (N-m) 0.104 N-m (ref: one N-m = 0.74 foot-pound)

Next determine the torque of the Proxxon MF 70 spindle, assuming a constant power of 100 watts. (Who knows what the torque speed curve is)

Torque (N-m) = [Power (kw) X 9,550] /rpm
Power (kw) 0.1 0.1 0.1 0.1
rpm 20,000 15,000 10,000 5,000

Torque (N-m) 0.048 0.064 0.096 0.191

It looks like maybe somewhere between 5,000 and 10,000 rpm it might work, but not knowing the torque speed curve for the Proxxon MF 70 motor, it's only a guess. Well it was only an idea.

Lets look at price points for "high speed spindles"
Sherline (from DiscountCampus.com)
#33050 High Torque DC Motor & S/C Assembly $210 discount to $194.25
#33060 DC Motor & Headstock Assembly W-S/C $312 discount to $288.60
#33070 10,000 RPM Headstock, Motor and $402 discount to $371.85
Speed Controll Unit

Taig
#200-55CR Spindle Motor (1/4 hp, 3,400 rpm $110
Continous Duty

High end engraving machine spindles (I don't know if the price includes motor)
Spindle unit High-torque spindle unit 3,000 - 12,000 rpm
High-speed spindle unit 5,000 - 20,000 rpm
High-torque milling spindle $800
High-precision milling spindle $1,800
High-speed engraving spindle $1,700

Specialized 50,000 rpm "engraving" spindle and motor $5,000

Now, the article "High Speed Spindle Design and Construction" Engineering Research Center for Net Shape Manufacturing - The Ohio State University - by William Popoli, President, IBAG North America - on the web site MMS Online (http://www.mmsonline.com/articles/hsm9802.html) shows that amongst the many critical factors, the bearings play an important role. The article developes the knowledge required to select proper bearings.

Now I've got a spindle that came with the machine. What if Little Machine Shop were to develop replacement spindle bearings, good for 30,000 rpm, continuous duty, permanently lubricated, no forced water or air cooling. That were pressed into a SIEG X2 spindle casting (will need ceramic balls and specific design criteria for selection of the proper bearing, and don't want to brinell the raceways or crush the ceramic balls when pressing them into the casting and on to the spindle). So a shop needs to do this (tooling).

Now we can turn the $549.79 (including shipping) MicroMark MicroLux milling machine #82573 into a 30,000 rpm mill for the price of a few bearings. If you want to try this yourself Boca Bearing sells bearings one at a time (www.bocabearings.com). They may even work with you to develop a selection for your parameters.

But where's the motor? Good question. In all my searching there is very little out there about high speed spindle motors. In this day and age there must be all kinds of candidates out there. I'm not an Electrical Engineer, so is there anyone out there that can help? Assuming the formulas for spindle torque are correct, what is needed is a motor (not an air motor - too noisy) that can be controlled, continuous duty cycle (some "engraving" jobs could take 24 hours non stop), self cooling, and can run at 30,000 rpm and deliver quiet, reliable, smooth Torque.

Just brain storming, why can't a dc servo motor be used?

Whelen

JRouche
07-31-2005, 01:34 PM
and can run at 30,000 rpm and deliver quiet, reliable, smooth Torque.Whelen

Nice article.

I would use an overly powerful, slower electric motor running through belts and cogs or pulleys to get the speed. Quieter, cooler and easier on the wallet. JRouche

tokyocrow
08-02-2005, 06:20 AM
who thinks the proxxon motor would work. If you look closely down the page here http://www.flashcutcnc.com/html/mach_acc.html#8000 you'll notice what appears to me at least to be a Proxxon motor repackaged as a high speed spindle. It doesn't have the same packaging as the micromill you've mentioned if you look at the Toolswitch site -however- the same motor is used in the handheld at Toolswitch - see http://www.toolswitch.com/prx-us-38481.php and as well the Proxxon micro mill sold here in Japan has the same yellow green motor housing with slightly different ratings (we're 100v/50hz here).

I'd be interested in hearing the Flashcut price for that spindle hehehe...

-tokyocrow

whelen
08-02-2005, 11:39 AM
Tokyocrow, youre right. Here is the pricing. Thanks for the great information.
Whelen

http://www.flashcutcnc.com/html/ord_price.html
Accessories for the 8000 Series Mills

NF-PM-148-211, NF-PM-148-275, NF-PM-148-952, NF-PM-148-260
Spindles / Dispensers
NF-PM-148-211 Spindle 100 W; 5,000-20,000 RPM; 1/8" Collet; Mechanical Height Compensation
NF-PM-148-275 Spindle 150 W; 5,000-60,000 RPM; 1/8" Collet; Automatic Height Compensation
NF-PM-148-952 Dispenser for liquids, grease, oil, paste, silicon, glue, sealant, paint, etc.
NF-PM-420-003-0500 Spindle 500 W; 11.000 - 25.000 RPM
NF-PM-239-110 Collet set .039" to 1/4" (14 pieces)
NF-PM-239-120 Collet set 3 to 8 mm (7 pieces)
NF-PM-148 991 4000 Spindle 500 W; 300 - 24000 rpm; 1/4- or 1/8 inch Collet; Tool changing system with length measuring sensor.

Part Number Description Price Spindles / Dispensers
NF-PM-148-211 Spindle 100 W; 5,000-20,000 RPM; 1/8" Collet; Mechanical Height Compensation $345
NF-PM-420-003-0500 Spindle 500 W; 11,000 - 25,000 RPM; ¼" and 1/8" Collets $495
NF-TI-6990 600 Watt 8000-24,000 RPM; ¼", 1/8" and 6mm (.236”) collets $545
NF-TI-2311 600 Watt 80-2500 RPM; 3/8", ¼", 1/8" collets, accepts other ER16 Collets $1,295
NF-PM-148-275 Spindle 150 W; 5,000-60,000 RPM; 1/8" Collet; Automatic Height Compensation (Floating Head for Engraving) $2,995
NF-PM-148 991 4000 Spindle 500 W; 300 - 24000 rpm; 1/4- or 1/8 inch Collet; Tool changing system with length measuring sensor. $4,995
NF-PM-239-110 Collet set .039" to ¼" (14 pieces) $295
NF-PM-239-120 Collet set 3 to 8 mm (7 pieces) $265

------------------------------------------------------------------------------

http://www.toolswitch.com/prx-us-38481.php
Proxxon Hand Held Rotary Tool IB/E (Looks like the Flashcut NF-PM-148-211 for $345)
Price: $ 105.00
This high-revving motor has full-wave electronic speed control capable of producing continuously variable speeds between 5,000 and 20,000 rpm and is usable for extended periods at a time. The ground steel spindle runs in a ball bearing assembly, minimizing play. Six high concentricity collets sized 1/32 in., 1/16 in., 5/64 in., 3/32 in., 7/64 in., and 1/8 in. (1.0, 1.5, 2.0, 2.4, 3.0 and 3.2 mm) along with a collet nut are included.
MICROMOT steel collets are hardened and thus have a high, consistent flexibility. They also maintain prolonged accuracy, even after regular use. The triple-slit collet is substantially more difficult to manufacture than the four-slit type, but offers a better load-bearing surface. This is especially important for cutters with small shank diameters. These collets should not be compared with unhardened, four-slit collets of brass and aluminum.
Features
· Ball bearing spindle of ground steel, with lock button for rapid cutter changing.
· Streamlined die-cast aluminum head for exact bearing seats and optimal stability.
· Quiet, powerful 100 W motor with full-wave electronics for continuously variable speeds between 5,000 and 20,000 rpm.
· Complete with six triple-slit steel collets covering 1/32 in. to 1/8 in. (1.0 - 3.2 mm).
· Packed in durable plastic case, complete with the 34 bits & cutters as shown above.
Package
· Rotary Tool IB/E
· Six triple-slit steel collets covering 1/32 in. to 1/8 in. (1.0 - 3.2 mm).
· Durable plastic case
· 34 bits and cutters
Technical Data
· Speed: Variable (5,000 - 20,000 rpm)
· Volts: 110-120V AC, 60 Hz
· Max Power: 100 W
· Length: 9 in.
· Weight: 1.1 lbs

whelen
08-02-2005, 11:51 AM
JRouche, thanks for the idea. Turns out that is what KDN Tool & Automation Engineering Co. is doing for me right now, as a part of their CNC retrofit to my SIEG X2 MicroMark MicroLux Milling Machine #82573. They know the capabilities of the X2 milling machine motor, and spindle bearings, and are implementing for me a belt drive conversion (nothing new, Little Machine Shop has such a conversion kit). But it seems that a spindle speed higher than 4,000 RPM is possible with other modifications to motor and spindle configuration. Which they are implementing.

Again thanks for the indormation.

Whelen

Halfnutz
08-02-2005, 12:33 PM
Wow, the specs on that Proxxon are impressive! Just all those colletts are worth having! And the price is great too.

(The oppinions above are the authors and do not represent those of CNCZone or its management.)

tokyocrow
08-03-2005, 01:44 AM
Whelen,

An option not mentioned yet ... just to throw it in the pot. Take a look at this beauty - it'll remind you of your last trip to the dentist!!

http://www.cncmasters.com/accessories%20page.htm#engraving%20attachment

There's a lot of drawbacks to air driven in general but 40,000 revs via an induction motor regardless of gears, belts or direct drive would have its own unique set of issues to deal with too.

--TC

JFettig
08-03-2005, 07:39 AM
I havent been able to read this entire post, but heres something that needs considering,
What max feed rates can you run? can you still take a decent chipload or will you just be burning?

At 30k your gonna need to be cutting at over 100ipm.(I didnt do the math, just a good estimate)

Jon

Halfnutz
08-03-2005, 08:04 AM
I have a 55,000 RPM air driven pencil grinder (from Harbor freight for 16.00 on sale) that fits into a 5/8" R8 collet with a tubular drawbar to feed the air supply. The TIR on mine is not good, but there are other more expensive models available. I saw the set-up somewhere and decided to try it out, and I'm in the process of making the hollow drawbar (god, I forgot all about that project). Its a neet way of getting an 1/8" bit to go 50,000 RPM on a mill, but I dont know how well the set up will work yet. Heres a copy of the link I got the idea from.

http://www.homemetalshopclub.org/news/feb04/feb04.html#mill

(The above oppinions are the authors and do not represent those of CNCZone or its management.)

tokyocrow
08-03-2005, 08:38 AM
Jon,

Hmmmmmmm. I had to stop and think about this for a bit. I routinely use a 30000 rev handheld for sculpting aluminum (JIS H 4100). At first thought you think "hey if can do it manually at 30000 than why can't a machine do it slowly at 40000?" ---but-- when I visualized the motion I make with the tool its probably very high rate strokes indeed although I doubt it would approach 100ipm. I think based on his previous posts Whelen is wanting an precision engraving/relief sculpting rig. Much the same as I am trying to figure out. I would assume he will be using tiny ball mill ends with 1/8th collet and not taking more than a few 1000ths at a time with thousands of passes thus chipload and feedrate would not be such a problem although maybe not in theory optimal for CNC in a machinist's context. As I'm new to CNC I think I'm missing something here though so anything you might have to add would be highly appreciated - I'm looking for a tool similar to Whelen's though with more workspace.

--TC

JFettig
08-03-2005, 05:40 PM
its not the speed you move it, its the speed it needs to be moved. if its rigid, you should be taking around .0005-.0008" per flute,
Any carbide has a suggested chip load, if you dont get that chip load, it will die prematurely, good luck running hss that fast;)


Jon

tokyocrow
08-04-2005, 09:05 AM
Jon,

Thanks for the info. I've obviously have a lot to learn hehehe. Is there some type of chart to read and calculate these ?

BTW right now I'm using CVD diamond tipped tools on 2mm (approx 1/8th inch) shanks - mostly ball shaped with no real flutes (more like a burr). I quit using anything but diamond because as you indicated they burn up too quickly. When and -if- I do get a mill I'll probably continue to use diamond though not CVD exclusively. Every bit I've bought in diamond I still have and use - even on green porcelain and sometimes on an occasional screwup I use them on bisque porcelain which is about like a grindstone to any tool. As a note for some reason in the U.S. diamond tools cost about 2x the price here in Japan.

--TC

tokyocrow
08-04-2005, 09:10 AM
Whelen,

I took a much closer look at the Proxxon motor(s) today when I was in the tool shop. I don't think they'd do so well after all - the cont rated duty cycle for the best Proxxon motors including the one Flashcut is using is 30 mins max. That was for 100v, 110v, 220v, and both 50/60hz.

--TC

whelen
08-07-2005, 04:52 PM
Tokyocrow
I looked into the CNCMasters idea you suggested. It looks like a router solution. Also I've continued researching "high speed spindles". They can be deadly. At speeds even as low as 2,000 rpm a broken bit or loosening collet can cause a lot of damage. Of course safety glasses are mandatory. I prefer a face shield. But what about the rest of the body. At high spindle speeds the flying bit becomes a projectile and can kill. By the way I'm not coming down on your idea. It's just the reading I've done has alerted me to the safety issue of high speed spindles. I've always wondered why engraving machines are enclosed in a "bullet proof" box. Well now I know. I'll be encasing my "engraving" mill within a "bullet proof" box. The articles I've read say that conventional engineered tool holding forces are NOT sufficient to hold "bits" at high spindle speeds. Using a technology engineered to cut wood for cutting metal is a very serious risk. Tokyocrow, thanks for your ideas.

Whelen

whelen
08-07-2005, 05:04 PM
Halfnutz, I've looked into the air motor approach to high speed spindles. It looks like a great idea. To generate the CFM (cubic feet per minute) air flow for the required torque, a good size air compressor is required. And the noise level of the air motor is very high. Economical solution but noisy.

Whelen

whelen
08-07-2005, 05:34 PM
Tokyocrow and Jon, you are right, an "engraving" tool is removing very little material, so high speeds can be used and still be within the chip load requirements of the tool. Yes carbide burs can be used for a roughing tool path which leaves material for a finishing "cut" with the engraving tool. The Designs Computed, Virtual Sculptor VS3D/VScad3 software allows you to design (CAD) in raster space and converts to vector space. It generates the tool path (CAM), and can rough cut and finish cut by allowing the precise specification of the cutting tool geometry(s).

As far as watts of power to do high speed engraving/sculpting/burnishing - the company to emulate is Roland. A leading Japaneese digital CNC engraving machine manufacturer. They have a machine for every price point. I'm trying to emulate the MDX-500. It comes with a high-torque spindle unit, 3,000 to 12,000 rpm or a high-speed spindle unit, 5,000 to 20,000 rpm. The spindle motor is dc brushless, 400 watts when with the high-torque spindle. So this gives an idea of the power required for a high speed engraving spindle. Tokyocrow, you were right in concluding that the Proxxon micro mill was under powered. My calculations also seemed to indicate that.

Also to repeat, these high speed spindle engravers are housed in a protective transparent box. A broken bit or loosened collet can cause a disaster.

Our conversations are interesting as they are similar to what we did in the concept phase, when I worked as an advanced development engineer 20 years ago.

By the way KDN Tool & Automation Engineering ( www.kdntool.com ) is studying a concept to get my stock SIEG X2 2,500 rpm bench mill to 9,600 rpm for engraving. They are interested in solutions as well as CNC conversions, and will work with you to get you to your application objectives.

Whelen

Halfnutz
08-07-2005, 10:10 PM
Whelan, Its definately a once in a while deal, not something for heavy use. I geusse the best use for it is pc board drilling, I've got a set of drill bits so tiny it's unbelievable, Ive tried using them with a 1/8" R8 collet at 2500 RPM and its too slow, they stick and break.
But yeah, for less than 20 bucks its a nice little tool to have in the shop, I use the little grinder for all kinds of stuff. Its easier to hold than a dremel, and at those speeds it makes a difference.

tokyocrow
08-08-2005, 08:18 AM
Whelen,

High Speed Spindle Safety is not really a concern for me as my wife makes sure I'm bound in leather, goggled, and plugged when I play -:) A full face shield would be a bit cumbersome though and detract from the pleasure as I couldn't see so well for closeup RCH work!! On the serious side though you're darn right about safety issues and I've seen less mention of it within CNCzone (why isn't there a safety forum?) and any other site as well, also lots of evidence (photos and videos) its a passive subject (as commonly the case everywhere) though it shouldn't be. BTW whatever CNC machine I wind up building/buying will be inside a 2cm thick composited granite enclosure with brushed alum frame and plexan portals and loads of exceptionally bright LED lighting. I have to admit though its actually less about safety and more about noise abatement and style (kind of cool design ain't it?) - we live in a Tokyo apartment where the expectations and tolerance of noise is quite low in comparison to the U.S. thus the heavy stone.

Engraving .... high speeds ... what a confliction eh? Arrrgghh! I've gone around full circle on high speed spindles. The machine I've pretty much decided to buy has a 220v 0-7500rpm VFD driven spindle (2HP). For some of the work I do however I'll have to go a lot faster. My current handheld runs at 35,000 and does a pretty good job. The problem for my work is that CNC at our ¥/$ level doesn't have any means to measure torque nor provide smart feedback to control how fast the tool takes a bite thus I think I'll need 40,000~50,000 with a light bite, slow feed rate, and plenty of experientiamentanation <as W would put it>. I know very little about feedrates, chiploads, cooling etc etc. and that somewhat frightens the analytical controlled process engineering side of my brain, however I keep on the right side of my brain the knowledge that shops all over Bangkok finish and engrave work for folks like Cartier and Harry Winston with about the same level of knowledge as I have using an accurately driven CNC mounted 50,000rpm tool that curiously has the same part number as a dental drill when sold in Japan.

Enough babbling ... my handheld's manufacturer recently introduced a new handpiece which I've been drooling over, now I've convinced myself that its the candidate for hanging on the CNC machine I eventually will get ... albeit its low torque compared to an air driven beast but a lot quieter. There's a lot of theory to shoot it down here in the forum but I'll make it work somehow the same as the guys in Bangkok do!! Take a look ... http://www.saeshin.com/new%20products.htm .. peek at the Forte 100. Not a lot of info on the English side but I'll pick one up when I'm in Seoul later this month. They also make a fine line of natural diamond burrs and toolends I swear by now.

--TC

whelen
08-08-2005, 04:42 PM
Tokyocrow, here are some speeds and feeds referances.

#1 http://www.gatewaycoalition.org/files/kinzel/tradmach/NVTraditional_Machining.ppt

#2 http://www.niagaracutter.com/techinfo/millhandbook/speedfeed/

Here is information on High Speed Machining

#3 Basic Math For Ball Nose Tools
#3 http://www.mmsonline.com/articles/1103rt3.html

#4 Lending a Hand to the Handbook
#4 http://www.mmsonline.com/articles/080309.html

#5 Industrial Engraving
#5 http://www.mmsonline.com/articles/1102bp2.html

#6 Four Tool Holder Quality Factors
#6 http://www.mmsonline.com/articles/119804.html

#7 What is High Speed Machining
#7 http://www.cnczone.com/forums/showthread.php?t=462

#8 Even slow spindle speeds can throw a dangerous projectile
#8 Safety at High Spindle Speeds
#8 http://www.mmsonline.com/articles/hsmdm/cut6a.html

Hope this helps.

Whelen

whelen
08-09-2005, 09:17 PM
To the people that have responded to my post. As I've mentioned, I finally realized that "high speed spindles" are a subset of "high speed machining". And that "feeds and speeds" have changed dramatically due to the advances made in "high speed machining" technology. I'd like to share some of the information I have found during my web searches on the topics: high speed machining, feeds and speeds, end mills, machining plastics, and chatter. I there is a company associated with the referanced web site, I have no affiliation with it - I just found the information interesting.

Starting with machining plastics - from what I have found it seems that the most productive way to machine plastics in a CNC milling machine, is with router speeds, and router tool bits. That goes for soft as well as hard plastics. The information in the following site was facinating to me, as I will be using plastic materials for my applications. The information is on three related web sites: http://www.onsrud.com , http://www.plasticsmachining.com , and http://www.plasticrouting.com - they are all related to Onsrud Cutter, or seem to be. The site with the most information (they are all packed with information) is http://www.plasticrouting.com/van.asp .

The next site contains speeds and feeds specifically for end mills, by diameter from 1/16" through 3", for premium cobalt high speed steel, and regular high speed steel, by material to be machined.

"Chatter Myths: Pieces of the puzzle in maximized machining", the end of the article gives an example #4, of 1/4" ball mill and its natural frequencies as related to rpm, and chatter. http://www.moldmakingtechnology.com/articles/090402.html

Proper Colleting and Collet Maintenance in CNC Routing of Plastic.
http://www.plasticrouting.com/pdf/Proper_colleting_and_collet_maintenance.pdf

GATEWAY - Traditional Machining - Department of Mechanical Engineering, The Ohio State University - by Dr Gary Kinzel
http://www.gatewaycoalition.org/files/kinzel/tradmach/NVTraditional_Machining.ppt

Milling Tips - High Speed Machining
http://www.manufacturingcenter.com/tooling/archives/1199/1199ctk.asp

The Ins and Outs of High Speed Machining
http://www.millstar.com/techarticles/article_008.htm

Niagra Cutter - New Concepts in Milling Handbook
http://www.niagaracutter.com/techinfo/millhandbook/speedfeed/

Hope you find these interesting.

Whelen

whelen
08-10-2005, 12:29 PM
I forgot to post the url for:

"The next site contains speeds and feeds specifically for end mills, by diameter from 1/16" through 3", for premium cobalt high speed steel, and regular high speed steel, by material to be machined."

End Mill Training - Speeds and Feeds
http://www.endmill.com/pages/training/spdfeed.htm

Also here are the articles that caught my attention - routing tool bits for CNC milling of hard and soft plastics.

http://www.plasticsmachining.com/magazine/2001-11/Van.html

http://www.onsrud.com/pdf/The%20Router%20Way.pdf

Whelen

whelen
08-23-2005, 11:00 PM
When I wrote up the subject of this thread I made a mistake. The mistake is in the calculation of the scoping torque required to engrave brass. The error is in my selection of the feed per tooth. I used 0.18 mm per tooth. I should have used 0.01 mm per tooth!!!!!

I found this out in a conversation with the gentleman that wrote the article which had the torque equation. I found the initial value of 0.18 mm per tooth in another referance. I only read one page and should have read the other 65 pages.

Backing up - I was calculating the torque required to engrave brass with a pointed engraving bit. The bit has a 60 degree included angle, and the depth of cut is 1 mm. Assume a rpm of 20,000. So re calculating:
1 mm depth of cut
1.16 mm width of cut ( up 1 mm from the point )
0.01 mm per tooth feed per tooth
2 teeth number of teeth
0.29 machinability factor for brass

0.0077 N-m Torque
0.77 cN-m Torque

462 mm per min Feed rate
18.2 inches per minute

Big difference in the resulting torque required. I guess the PROXXON might work. But may not hold up to a continous duty cycle, as Tokyocrow pointed out. But for the money, Tokyocrow has found better alternatives.
I got the new feed per tooth of 0.01 mm from the assumption of 1 percent of the tool diameter (1.16 mm) per tooth.

Whelen

JFettig
08-24-2005, 08:14 AM
Whelen, just a quick idea, I have engraved around 10ipm with a 3000rpm spindle. at 18.2ipm and 20,000rpm your going to be burning up bits.

Jon

whelen
08-24-2005, 10:20 AM
JFettig
Thank you for taking the time to help me get back down to earth. The cost to "reliably" get to 20,000 rpm, and the consumables cost for the bits I will be burning up don't add up.

Again thanks for your help. Also I enjoy reading your posts, helping others with their problems.

Whelen

rustfinger
02-01-2006, 03:48 PM
I have just found this forum and fairly new to the mini cnc scene. I also have been trying to come up with a high speed spinde for my mini-mill. I have the grizzly version of the Seig x2 which I have converted to cnc last year.
I have been engraving some small items and I cant do a very good job with small cutters at the 2500 rpm the mill tops out at. I read the entire thread and looked at most of the links.
I find the mini air spindle an intriguing possibility, except for drilling a hole in the drawbar (although if a long hollow bolt could be purchased, it may be easier to set up).
I have a harbor frieght trim router that I had thought about using, but it is too long to fit under the mill head and mounting it on the side would be ok, except for the loss of working area.

Has anyone considered mounting a DREMEL high speed grinder, using either: the flexible shaft attachment (maybe it could be fed through the spindle?) or the right angle attachment, mounted under the millhead?

Since it is mainly for engraving, I would think that the power would be sufficient and the speed is adjustable (usually 0-35,000 rpm).

If anyone has thought about this, or something similar, any help would be appreciated.

Halfnutz
10-05-2006, 04:18 PM
Using the flex attachment of the Dremmel has been discussed, but the runout is the major drawback.

There are so many variables in high speed machining it is difficult to settle on a single solution for everything. I made one of the hollow drawbars for the air spindle and as with the Dremmel, the runout is high.

I think the biggest problem is that "high speed" and "low cost" just dont mix well with "accuracy" and "machining".

I've settled with the stock spindle and an 1/8 in. drill bit for most soft metal engraving. I saw a R8 high speed spindle on eBay recently for around 300 dollars, similar to the one pictured. Eventually I will find one of these at a resonable cost I hope.

whelen
10-07-2006, 11:12 AM
Halfnutz, I found my high speed spindle solution. Or I should say KDN Tool found it. I wrote it up on 8-2-06 in Benchtop Mills titled - High Speed Spindle for SIEG X2 - I found it.

8-2-06 "High Speed Spindle for SIEG X2 - I found it". 5,000 to 20,000 rpm with six collets 1/32" to 1/8" - for $170, which includes the mounting bracket for the SIEG X2. You will find it on www.kdntool.com

Bill Perun

Halfnutz
10-07-2006, 04:02 PM
Halfnutz, I found my high speed spindle solution. Or I should say KDN Tool found it. I wrote it up on 8-2-06 in Benchtop Mills titled - High Speed Spindle for SIEG X2 - I found it.

8-2-06 "High Speed Spindle for SIEG X2 - I found it". 5,000 to 20,000 rpm with six collets 1/32" to 1/8" - for $170, which includes the mounting bracket for the SIEG X2. You will find it on www.kdntool.com

Bill Perun

Nice! they have some great stuff at KDN. I am looking at buying (or trying to copy) a couple of there products for my X2. All of their stuff is top notch.

gone4pepsi
12-12-2006, 10:13 AM
Check these out. This guy has definitely done the work already.
http://stores.ebay.com/Wolfgang-Engineering

gone4pepsi
12-12-2006, 10:19 AM
I recently bought a minitech mill, used. i haven't been able to get it to respond to any software. I'm pretty green to the cnc world here, that's why I'm here.

i've connected the mill and can here the fans running, but i'm unable to get mach 2 or mach 3 to respond or jog any of the axis.

Can anyone help me determine if i have a driver problem or if it's just my misuse of the software.
This mill checks out mechanically and looks to have been hardly used,according to the ball screws and the overall condition. Mecahnically everythting moves and appears to be in good condition.
i have entertained the option of replacing the controler and the steppers, which will still leave me under what i could buy one of these mills for.

I really don't want to spend unecessary cash for parts i don't need , if i don't have too.

Remember, I'm a novice and very green. So please be easy and help me .
Thanks
mark

rustfinger
12-12-2006, 12:38 PM
Thanks for the reply...
Since I posted that- about the spindle, I have ordered a spindle from Wolfgang, I have not incorporateded it into the mill yet. I am constucting a small mill to use it with. The spindle lookg stout enough to do some serious machining of small metal parts. I think the X2 will be too loose to get good work, but I have a small bracket, I may mount it up to do some engraving.

If anyone has used this Wolfgang spindle- please share your experiences.

About the minitech mill, since you are new, my suggestion is you investigate the type of controll the mill has-
Is it a PC type Parallel port ? or a serial Port? sometimes the 25 pin d-sub type connector is used for either one. a 9 pin is usually a serial port and rarely a parallel port.

Second- if it is a parallel port, you need to determine the step pin and direction pin for each motor axis.
Mach 2,3 use two pin signals for each motor axis. You can configure which ones are used within the software in order to match up to your machine.
The best way to get this information, about your machine, is to get the original documentation. Without that- it will be difficult.

If you cant get documentaion, you could examine the connector to see which of the 25 pins are used- sometimes the non-connected pins will be missing from the housing. If it is connected to a pc board- you can see if they are connected to circuit traces or not. Check this with the power off of course.

Good luck.

gone4pepsi
12-12-2006, 02:05 PM
This gentleman has developed some spindle setups with 3 ceramic that will up to 60000 rpms bearingshttp://cgi.ebay.com/TB-350S-High-Speed-Precision-CNC-Router-Spindle_W0QQitemZ170022306647QQihZ007QQcategoryZ2594QQtcZphotoQQcmdZViewItem

He has other configurations also check out his other spindles

Halfnutz
12-12-2006, 04:55 PM
First of all verify you have Mach3 set up correctly by checking the direction pins of the printer port outputs with a DVM. They should change from around OV to 3-5V as you change directions jogging.

Then verify you have logical power and motor power to the drives, and if so when you turn the unit on the motors, if wired correctly, should hold thier position.

At that point it is simply getting a step and direction signal from the printer port to the drives.

Nothin to it eh?

gone4pepsi
12-12-2006, 10:15 PM
First of all verify you have Mach3 set up correctly by checking the direction pins of the printer port outputs with a DVM. They should change from around OV to 3-5V as you change directions jogging.

Then verify you have logical power and motor power to the drives, and if so when you turn the unit on the motors, if wired correctly, should hold thier position.

At that point it is simply getting a step and direction signal from the printer port to the drives.

Nothin to it eh?

I did check the motors when powered up and i can't move them as i could when power is off, but i have not what you mean , in reference to checking the pins on the printer port.
Also I have no idea what the configuration of the pins are suppose to be in the software configuration, because minitech is not helpful at all. i guess i'd have to spend * grand to get that info.

Thanks
Mark

gone4pepsi
12-12-2006, 10:58 PM
This gentleman has developed some spindle setups with 3 ceramic that will up to 60000 rpms bearingshttp://cgi.ebay.com/TB-350S-High-Speed-Precision-CNC-Router-Spindle_W0QQitemZ170022306647QQihZ007QQcategoryZ2594QQtcZphotoQQcmdZViewItem

He has other configurations also check out his other spindles


When i booted up my pc, xp told me I had new hardware and was looking for the drivers. i unplugged the paralell cable, rebooted, and now i don't see xp looking for the drivers. any ideas? Does minitech require it's own drivers,or do you think this is a glitch in mach3 or my pc?
Thanks
Mark

finance
01-04-2007, 06:00 PM
Hi Mark,
MiniTech only sell the base, manual machine. What you have is one that has been modified by someone.
You don't need 'minitech drivers' there is no such thing. So the Minitech guys, even though they are very helpful, cannot help you at all.:(

Get onto the Artsoft Mach3 site (http://www.machsupport.com) and check out their tutorials, they will give you information on how to set Mach3 up and also info on setting up the port pins etc.

If your steppers are locking up when you have power to the drivers then it sounds like you're half way there, you just need to get the PC/Mach3/Driver interface working - which should not be too hard (I note you are a complete noob, but trust me) :).
Whatever you do, do not rush into this, take the time to ask as many questions as it takes before you know what you are doing or you may fry your driver(s) and/or PC.:nono:

What driver(s) do you have to drive the stepper motors (I'm assuming they are steppers and not servo motors). Some common ones are Xylotex and Gecko - or in your case someone may have built a driver from an Oatley Electronics kit (check out www.oatleyelectronics.com (http://www.oatleyelectronics.com) and look for stepper motors/kits).

Mach3 does some things that Windows doesn't know about, so look on the Artsoft web site for instructions about optimising XP to let Mach3 run correctly - if you have other things running that clash with Mach3 Windows won't know what is going on. Basically you can't have anything else (even a screen saver) running while you have Mach3 running, it's best to have a dedicated PC for Mach3 (ie don't use the PC for anything else). Also check out the minimum PC requirements for running Mach3, you'll find that on the Artsoft site too.

Getting back to your question, it sounds like XP has detected that signals are getting to the PC from the driver board(s) and thinks you have some sort of printer attached, this indicates that it may require rewiring the connection between driver and parallel cable - one thing to check is that you have a straight through parallel cable with all pins connected, some cables don't have all wires connected and some cross a wire or two getting from one end to the other. Check for continuity with a multimeter (set on Ohms) between pin one of one end to pin one of the other end - do that for all pins, you should see zero Ohms in each case - if you don't, get another cable.
You will need to get info from the driver maker to be sure that the connections to the parallel cable are correct, if they are OK and your cable is OK then it should be easy to set up the port pins in Mach3 - and away you go. ;)

Good luck and Cheers,
Dave.


drivers
When i booted up my pc, xp told me I had new hardware and was looking for the drivers. i unplugged the paralell cable, rebooted, and now i don't see xp looking for the drivers. any ideas? Does minitech require it's own drivers,or do you think this is a glitch in mach3 or my pc?
Thanks
Mark

rustfinger
01-05-2007, 01:16 PM
Mark,

If what finance says is correct, you are left with no other choice than to open up the controller box and look at the circuit board. Hopefully you will find a name on it, maybe also a model number, and you can "Google" it to get information on the internet.

Then maybe you can get the manual. Just be sure to unplug it first and groung yourself by keeping one hand on the metal of the box, or by not touching anything- basically the same static electricity precautions you would have while working on your PC.

If you cannot fins a name - you can take a good picture of it and post it on this thread- or start a new one.

Rustfinger.

gone4pepsi
01-05-2007, 01:52 PM
Hi Mark,
MiniTech only sell the base, manual machine. What you have is one that has been modified by someone.
You don't need 'minitech drivers' there is no such thing. So the Minitech guys, even though they are very helpful, cannot help you at all.:(

Get onto the Artsoft Mach3 site (http://www.machsupport.com) and check out their tutorials, they will give you information on how to set Mach3 up and also info on setting up the port pins etc.

If your steppers are locking up when you have power to the drivers then it sounds like you're half way there, you just need to get the PC/Mach3/Driver interface working - which should not be too hard (I note you are a complete noob, but trust me) :).
Whatever you do, do not rush into this, take the time to ask as many questions as it takes before you know what you are doing or you may fry your driver(s) and/or PC.:nono:

What driver(s) do you have to drive the stepper motors (I'm assuming they are steppers and not servo motors). Some common ones are Xylotex and Gecko - or in your case someone may have built a driver from an Oatley Electronics kit (check out www.oatleyelectronics.com (http://www.oatleyelectronics.com) and look for stepper motors/kits).

Mach3 does some things that Windows doesn't know about, so look on the Artsoft web site for instructions about optimising XP to let Mach3 run correctly - if you have other things running that clash with Mach3 Windows won't know what is going on. Basically you can't have anything else (even a screen saver) running while you have Mach3 running, it's best to have a dedicated PC for Mach3 (ie don't use the PC for anything else). Also check out the minimum PC requirements for running Mach3, you'll find that on the Artsoft site too.

Getting back to your question, it sounds like XP has detected that signals are getting to the PC from the driver board(s) and thinks you have some sort of printer attached, this indicates that it may require rewiring the connection between driver and parallel cable - one thing to check is that you have a straight through parallel cable with all pins connected, some cables don't have all wires connected and some cross a wire or two getting from one end to the other. Check for continuity with a multimeter (set on Ohms) between pin one of one end to pin one of the other end - do that for all pins, you should see zero Ohms in each case - if you don't, get another cable.
You will need to get info from the driver maker to be sure that the connections to the parallel cable are correct, if they are OK and your cable is OK then it should be easy to set up the port pins in Mach3 - and away you go. ;)

Good luck and Cheers,
Dave.


drivers

I beg to differ. Yuo are wrong, everything on this mill is minitech.
Jack has contatced me everyday since i posted at the forum for mach 3 software. Art tried to help, but had no idea about Jack's machines.


Jack walked me throuhg everything and after trouble shooting, we have come to realize that the board was bad.

FYI the board says Mini tech right on it.

After configuring the pins, it came down to me isolating the drives whith each motor..

There was no one at the mach 3 forum that was of any help , with the exception Of Jack from Minitech.

Art tried to help, but had no idea where the problem could have been..

The original problem was in the software.
Jack researched it for me and emailed me the information , and finally after days of deliberating we unchecked all of the active lows to all the axis and bingo we had a response.


Jack offered to salvage a board from an older machine.

I've decided that i'm just going to upgrade to a bipolar controller and higher torque motors.

If anyone is inteested, These motors are the oriiginal and have been tested. I've have no idea what the holding torque is, but they are all equal and in excellent condition
They are unipolar, six wire and i'll let them go real cheap.


If anyone needs help with an older minitech, i'm sure Jack will be more than happy to hear from you. Just email him.
Mark

Stepper Monkey
01-06-2007, 06:56 AM
Back to possible motors to drive spindles, there are some amazing brushless DC "outrunner" motors designed to replace the old-fashioned gasoline engines on really large model airplanes - as in 25 - 30+ pound model airplanes! These motors really crank out an amazing amount of power, and being brushless they have PWM speed controls that can be used manually or with Mach3 or other software with PWM capability. They come in any number of sizes, and are all under a hundred bucks or so except for the really big ones. They also only weigh a few ounces!

I believe this is the same type of motor Wolfgang engineering uses on thier highest-end spindles.

I am using one to build a new spindle drive to replace an NSK Astro unit, as I don't want to spring for that kind of hardware again!

Has anybody else had experience with these as well?

finance
01-07-2007, 06:00 PM
Well,
I'm glad that you seem to have sorted out your problem.

For everyone's info, there is a bunch in Australia called MiniTech - it was them I thought gone4pepsi was referring to - I was unaware he is in the USA and he obviously didn't know I'm in Australia.
:withstupi
Check out www.minitech.com.au (http://www.minitech.com.au) they are excellent to buy from/deal with.

Cheers,
Dave.


I beg to differ. Yuo are wrong, everything on this mill is minitech.
Jack has contatced me everyday since i posted at the forum for mach 3 software. Art tried to help, but had no idea about Jack's machines.


Jack walked me throuhg everything and after trouble shooting, we have come to realize that the board was bad.

FYI the board says Mini tech right on it.Mark

Anodizer
03-28-2007, 09:54 AM
If the noise is not a real problem and you have an adequate air supply, look at the Sioux pencil die grinders, # 5978A (54K rpm) and # 5979A (70K rpm). the 5978A is the one Sherline uses in their high speed head.

Fred
The Anodizer

scubasteve_911
08-23-2007, 02:55 PM
Back to possible motors to drive spindles, there are some amazing brushless DC "outrunner" motors designed to replace the old-fashioned gasoline engines on really large model airplanes - as in 25 - 30+ pound model airplanes! These motors really crank out an amazing amount of power, and being brushless they have PWM speed controls that can be used manually or with Mach3 or other software with PWM capability. They come in any number of sizes, and are all under a hundred bucks or so except for the really big ones. They also only weigh a few ounces!

I believe this is the same type of motor Wolfgang engineering uses on thier highest-end spindles.

I am using one to build a new spindle drive to replace an NSK Astro unit, as I don't want to spring for that kind of hardware again!

Has anybody else had experience with these as well?

Little late of a reply, but I have considered outrunner motors.. One huge problem is that they cannot get rid of heat when they are at rest.. Airplanes give access to tremendous amounts of airflow, a CNC, however...

Another problem is their tiny 2mm-3mm shafts. Finally, the fact that the outer-rotor spins creates problems with vibrations. The only good way is to use inner rotor brushless motors, which are hard to find with a large enough shaft diameter. You could use a frameless brushless motor from Danaher Motion, but they're damn expensive.

Steve

SirDave144
08-25-2007, 02:06 PM
Just brain storming, why can't a dc servo motor be used?

Whelen

DC servo motors are brush motors. That implies limited life at high speed.

There are many either 3-phase 400 Hz aircraft typr motors or BLDC (Brushless DC) motors which should have no brush life issues and may be reasonable choices.

High frequency drive (e.g. well above 60 Hz) tends to result in a lighter, higher speed motor.

Dave

Tolik
08-30-2007, 01:20 PM
Little late of a reply, but I have considered outrunner motors.. One huge problem is that they cannot get rid of heat when they are at rest.. Airplanes give access to tremendous amounts of airflow, a CNC, however...

Another problem is their tiny 2mm-3mm shafts. Finally, the fact that the outer-rotor spins creates problems with vibrations. The only good way is to use inner rotor brushless motors, which are hard to find with a large enough shaft diameter. You could use a frameless brushless motor from Danaher Motion, but they're damn expensive.

Steve

I strongly agree about heat dissipation problem, but some motors are coming with water cooling units. For most of hi quality inrunners are pretty easy to fit some homemade water cooling jaket.
Another realy BIG problem - a very BIG current consumtion. You PSU should be ready to provide from 30A(min) till up to 200A at 12 - 36 VDC.


Another problem is their tiny 2mm-3mm shafts
5 & more mm are avaible.

Look at
www.kontronik.com&
www.neumotors.com brushless inrunners and electronic speed controllers. I think that these are the best for diy hi speed spindles. Now I`m planing to build one with
such (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=300138978297&ssPageName=STRK:MEWN:IT&ih=020) motor.

scubasteve_911
08-30-2007, 06:35 PM
Tolik,

I don't really have a problem with cooling of inrunners, that's not very difficult. For the savings in comparison to a commercial precision spindle motor, you can afford watercool it without much effort. I didn't know these existed, it is starting to make me think :)

I would use a car battery charger for the supply. Any other option requires rewinding the motor, then finding a decent high frequency drive. I don't think most VFDs can run that high.

I would be very grateful if you kept me in the loop of your spindle progress. You've gotten me to consider doing my own, since I didn't know that they existed as inrunners. Perhaps a good spindle setup would be a set of preloaded angular contacts at one end, the rotor magnets, then a smaller rear radial bearing. This might make assembly possible. Disassembling the magnets might not be worth it..

Direct drive is the only way that I would put forth effort for a spindle. I have a 400W brushless motor taken apart that I was considering converting from an 8-pole to a 2-pole for higher speeds, but it is hard to find magnets I know will work.

I'm actually designing a fully magnetic-bearing based spindle for my degree project this year. I was gearing it for the DIY community since it will be relatively inexpensive compared to commercial units. But, you would need a lathe and milling machine to make it.. Also, the circuitboard will be quite expensive. But, it will last a long time without wearing out and will be very accurate.

Steve

Tolik
08-31-2007, 02:59 PM
Scubasteve 911,


I didn't know these existed, it is starting to make me think :)

Here is example of water stuff from NEU MOTORS (http://www.fastelectrics.com/blmotors1.asp)- less than 20 USD (without shipping) & you are ready to go with more than 2.1 cont / 3.3 max (30 second) KILOWATT, & rich up to 60 000 Rpm with NEU 1527 series motor.


I would use a car battery charger for the supply.
For 400 Watt motor should be enough. I tested the motor like this - 540W/5200 RPM/V, connected to my PC SMPSU 12V rail. It was working fine. With your charger that able to provide 14.4 - 16V will be even better.


Direct drive is the only way that I would put forth effort for a spindle.
Strongly agree with you - this is the best possible way.


But, you would need a lathe and milling machine to make it..
I need to talk with my boss. If he will allow me, I`ll use one of CNC lathes / mills at my work. The thing I learned : for all DIY activitys, industrial stuff is the best choice... But $$$ :(


Also, the circuitboard will be quite expensive.
If you about motor controller - I`m not shure. 100A/ up to 40V controller (http://www.himodel.com/electric/HiModel_FLY_Seires_4_10S_100A_Electric_Speed_Controller_for_Helicopter_Type_HV_Heli-100-OPTO.html) will cost around $120...150 including delivery.
In addition, to control the controller you will need some pulse modulator. The signal used to control ESC is a square pulses 70-220 mS length, 50 pulses per second. I already have some schematics of this stuff, so just ask me if you interesting. Parts for modulator at any local store should cost less than $10 for analog, or $15-40 for PIC based project.
Now I`m trying to design more advanced controlling unit, that will able to work with spin/RPM encoder (& even may be work with PC) , to provide :
A - stable amount of RPM (to eliminate RPM drop when tool touching the part, or if PSU/mains voltage changed)
B - feedback to PC/CNC controller to allow change RPM for each cut/job, & to make possible to use G96, G97 commands.


I would be very grateful if you kept me in the loop of your spindle progress.
I`ll be happy to share any information, but I need a time to complete this project. Especially electronic part.

Now I have one question.
Look at this (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=160136751889&ssPageName=STRK:MEWA:IT&ih=006) ER 8 3/8" STRAIGHT SHANK COLLET EXTENSION . Is it possible to fit it to 3/8 ID bearings without additional tooling ? Anybody tried to do this, and what are you experience or suggestions ?

scubasteve_911
08-31-2007, 11:08 PM
Hi,

The circuitboard expense I was referring to was the one I am designing to control the spindle. This includes the magnetic bearings, sensor-feedback loop, position loop, current control loop, and the pwm for the motors and bearings. It's a 6-layer PCB and will have about 400$ in parts on it.

You can rig up a basic velocity loop with hall-effect feedback and output the standard pwm to interface with the driver very easily. I would prefer using a PSoC microcontroller since they're extremely easy and quite powerful.

For the ER collet system with the 3/8" shank, I can't think of an easy way to use it. Sure, you can load some 3/8" ID bearings into an open-ended housing, then loctite the ID of the bearings after a bit of roughing up, but I am not sure how reliable that is. Furthermore, how would you couple the motor? I've heard of some inline couplings that could work with a motor, but I'm not a fan of them. The motor should be in between these bearings, so, I don't see how that is easily implemented. You also need a method to preload these to minimize axial and radial play, not sure how you'd do this either.

Steve

Tolik
09-01-2007, 05:21 AM
Hi,


You can rig up a basic velocity loop with hall-effect feedback and output the standard pwm to interface with the driver very easily.
I`m prefer the optical sensor (for speeds below 40-60K RPM), but your idea seems to be good also.

Thank`s for you sharing your look to the collet system. I considered that I`ll
need to make my own shaft that should to be be precicely fitted to ID of bearings. Loctite is useless here. Some later I`ll plase here my entry design.
Can you to read Solidworks part & assembely files ?

scubasteve_911
09-01-2007, 07:00 PM
Yes Sir, I'm all ready to go with Solidworks. I'm eager to check out what you have done :)

Steve

bilinghm
02-25-2008, 11:47 AM
Is the limiting factor on high speed spindles the bearings? If so, cannot high speed bearings be retrofitted into a machine like the X2 or X3? Certainly the balance of the spindle would become a factor at really high speeds, but 10,000 rpm doesn't seem extreme.

pzzamakr1980
02-28-2008, 01:52 PM
There are quite a few limiting factors. The bearing are a major one, with heat dissipation a part of that. There are also vibrations, which at 4000rpm or 2000rpm are not noticeable, at 10,000 they are a problem. There is also the factor of motor hp, generally too little. And consider runout on the spindle as well. When you use small cutters spinning at high rpm, runout can break those expensive little cutters.

philbur
05-30-2008, 08:54 AM
Expensive bearings only work if they are setup exactly right. So the housing and spindle shaft need to be manufactured to tight tolerances with regard to diameters, squareness, surface finish, and concentricity. You can put the glass slipper on the ugly sister but she'll still the ugly sister.:)

Phil


Is the limiting factor on high speed spindles the bearings? If so, cannot high speed bearings be retrofitted into a machine like the X2 or X3? Certainly the balance of the spindle would become a factor at really high speeds, but 10,000 rpm doesn't seem extreme.

bilinghm
05-30-2008, 10:39 AM
Well, I bought a 700 watt motor, 10,000 RPM bearings, made the pulleys and mounting plates, and I'm about ready for a test. So we shall see.

Herbertkabi
05-30-2008, 11:00 AM
I have built dozen high speed spindles. The first problem - bearings. First spindles I used thin section 1/2 ID bearings - four in lower side, two in upper side ... yes, good enough, but only for couple of months when every day millings. Only super precision angular contact bearings are really good. For shaft I use ER11 straight shank extensions. When 1/2" shank, then 1/2/001 AC1 TA from
http://www.grw.de/english/spindellager.htm. Collet chuck like ebay Item number: 160201209960
http://cgi.ebay.com/ER11-1-2-SS-COLLET-EXTENSION-W-WRENCH_W0QQitemZ160201209960QQihZ006QQcategoryZ57026QQtcZphotoQQcmdZViewItemQQ_trksidZp1713.m153.l1262
Some kind of labyrinth you have to design. I added my own "flying-seal" too.
See on the drawing how.
Of course direct drive but not rigid, my selfmade flex coupling I is the best for me. How coupling - its very important.
Motors I have built myself as well, but never was able for needed balancing. Lehner 19** are good, 22** also - up to 50k RPM. Last spindle I built used Kontronik Tango 45-13 , with 24V it makes nice 33.000, no load current few ampers, when normal cutting with 1.6...2.6mm endmill then you even do not see difference, when 6mm endmill then current still 3...4...5A , even in extreme situations never jumps higher than 10...15A. Tango never hotter than 50C degrees, well balanced ... the only problem is woooooooooo-howling because number of fan blades made especially for this effect" ... but hopefully you can find out how to reduce this. Lehner need good cooling, I used milling coolant system for cooling Lehner. Lehner and Tango are slottless motors, no cogging but Plettenberg HP 220, especially HP 300 are also very(!!!) good up to 25k rpm, HP 370 ise perfect for more larger spindles.
Better when possible to select the best motor from bigger store - to try in own hand with full rpm - some motors are more balanced than anothers ... but mostly all mentioned are OK. Plettenberg allways! Used ones from ebay are good enough when bearings replaced. Motor bearings I replace even when brand new motor!
Outerrunners? Yes, but not so high rpm and you need sure protect it from metal dust ... Outerrunners never balanced as needed.
I use very good AEG AC 2000 power supply regulated for 24V, speed control - common RC stuff as well - I use Schulze ... and common servo tester for.
Attached some photos about my last spindle. Dust protection, simple thing, you do not see, also included picture where some parts machined from 4, 5 and 6mm 7075 aluminium - it takes ca 2 hours to cut this quantity of parts (some are even anodized - I do not anodize myself). Very seldom I mill with less RPM than 33k.
Regards,
Herbert

praetor
06-02-2008, 11:01 AM
Herbertkabi would you happen to have any more spindles...maybe for sale?
or could you possibly share the process of making one as per your diagram?

Herbertkabi
06-02-2008, 08:59 PM
Seems next week I will start with new spindle. Then, when interest indicated of course, I will show the progress step by step.
For sale? Im not sure I can find so much time right now.
OD of main housing is 43mm x 110mm, stainless steel, next housing wheres motor - aluminium (aluminum ;-)
And please do not forget - this is Kabi Spindle - high speed spindle what every at least mediocre machinist is able to build himself ;-)
There is no special color codes - wast just my odd joice. Type of shaft and bearings you know, at least I hope so.

Regards,
Herbert

bilinghm
06-02-2008, 09:49 PM
Here is my modified X2 spindle. Read more about it at:
http://www.cnczone.com/forums/showthread.php?p=459019#post459019

Bill

praetor
06-08-2008, 05:52 PM
Herbertkabi would it be ok if you shred the motor portion of your high speed spindle? I would like to replicate this spindle..i have the ER 16 extension and would like to adapt this concept to make my own spindle...if it's all right?

Herbertkabi
06-09-2008, 02:26 AM
No problem with "replication". What is shank diameter of your ER16 extension, what bearings you plan? About what RPM you are thinking? When everything is ready I have "over machined" even collet nut - it caused vibration.
Yesterday I finished my new stainless housing, bottom flange, sleeve for upper bearing.
This time everything have been precise made with first try.
Unfortunately ER11 extension I ordered 22. May not received up till today.
My new spindle will make 45.000 RPM (24V). Water cooled - - milling coolant will flow first off through Spindle - no dust inside, no fan howling anymore.
Regards,
Herbert

Herbertkabi
06-09-2008, 03:59 AM
You can see the cone, will be hot-pressed (!) on to the shaft (collet shank) and then at least one time more precise machined. One of my previous pictures you can see collet nut key and clamp made from C10 fiber - I hope you understand why and how, Im very pleased with this system. Cone is also part of labyrinth together with bottom flange. This side of flange will be also one time more machined to get precise shape. Inside of this flange will place teflon seal against inner ring of demolished R1212 bearing - very simple and works sure. This bottom flange is bolted with 6 x M2 screws to housing (Im not able to make precise inner/outer thread ;-), teflon seal just tightly sitting inside flange.
Herbert

Herbertkabi
06-09-2008, 04:14 AM
would it be ok if you shred the motor portion of your high speed spindle? I dont understand what you mean - "shred the motor portion..." - my English is very DIY ;-)
Herbert

praetor
06-09-2008, 08:55 AM
I want to apologize for my misspelling I meant "share", can you share the information of your motor build. as i said i have the ER 16 extension and would like to adapt the same concept you used with your spindle. I would like to connect my spindle build to a motor, too.

Herbertkabi
06-09-2008, 11:00 AM
See the upper end of spindle, aluminium "fixator", When shaft is ended then emty "cup" - fill silicon compound in to "cup" - oiled pinion on to motor shaft, put it together, motor need to be accurete centered inside of housing. Next morning take it apart, cut away excessive silicone - now you have flexible high speed coupling. Better when less number and bigger tooths, or you can machine yourself like pinion or stern. It is laughable simple but this is the best I have tryed, works great, no stupid noises, no vibration.
Of course it is better to make any special stopgap for molding - it need to be well centered. My motor is fixed inside the housing beween rubber strips (or o-rings when water cooled) - I like silent machines. When you are building not so high speed spindle, but will need/use more torque - then may be you need to use bit stronger compound but silicon or rubber anyway. At that you "cup" will be bigger than I have, you can use more serious Stern (pinion).
Herbert

Herbertkabi
06-10-2008, 03:44 AM
Hereby some more detailed pictures for better understanding the upper side.
On the the shank you can see perimetric V-groove -> "fixator" has three M3 sharp-ended setting-screws (rad.120*). Also "fixator" has three axial screws (ax.120*) - M3 flat-end setting screws -> through steel dish -> through inner-ring of upper bearing -> through long sleeve on the shaft - gives preload to bottom bearing system. Upper bearing placed inside of slide and preloaded by spring.
Also I hope that my flex high speed coupling is bit more understandable now.
Regards,
Herbert

Herbertkabi
06-10-2008, 07:38 AM
Motor housing, made from aluminium, is near ready too. Unfortunately up till today not received ER-11 collet extension I ordered three weeks ago. I dont want to take apart my last spindle to go on with new one. What I can do? Nothing more than to wait. Just in case I will order one more extension, fom some onother place. Motor I will use : Two pole brushless ironless, slotless (airgap windings) no cogging ... Kv: 1800RPM/V , Weight: 449g
Shaft: 6mm , Size: 63x45mm, max Voltage: 36v ,Highest rated power: 2800W ;-) You do not need to be wonder about this huge power - this is maximum, this is RC-stuff - good stuff ;-)
I tryed with 24V - no load current was 4A when 44.000 RPM - so - not more than 10A (240W) will be seen when normal milling with up to 6mm endmills. Vibration is very low as well as noise. Because high speed and because not the best available materials (most expensive) have been used - it comes bit too hot - because I decided to go to water cooled - coolant liquid will go through spindle before goes to normal mill cooling. Motor I found, bought and already received was astonishingly cheap - $37.00 + shipping. Normally just only rotor costs at least two-three times more. Because I know a thing or two about motors I can detect that this is copy or replication of Lehner wheres 22** serie costs EUR 270...300... Welcome to Asia ;-)
Regards,
Herbert

Herbertkabi
06-11-2008, 08:26 AM
Flange is bolted to housing, machined more close to right shape, added teflon seal (not pressed to right depth jet), fits exact with inner ring of R1212, exact how its was done with my last spindle, works at least 12 hours every day. Im thinking about ... perhaps will use a bit more massiv inner ring like from R8 ZZ - this part of seal supports lower bearings as well. Will see. I have the time inasmuch as ER11 1/2" extension theretofore not received ... and no reply to my questions from seller ...
Next Im starting with tests of my water cooled system. I hope that these o-rings seals will keep coolant away from unwanted places, I hope it will be hermetic and works llike vibration (400hz ...750hz) damper as well.
Herbert

praetor
06-11-2008, 11:16 AM
Thank you very much Herbertkabi, I appreciate you sharing this information with me and wil use much of your concept on my spindle and will also share pics and progress on my ER 16 high speed spindle build.

Again, Thank you.

Herbertkabi
06-11-2008, 04:00 PM
Again, Thank you.
hi praetor, what kind of bearings you planned? I hope you will find good ones.
I have built by another schemes too but this is the best at least for me. As I told - works minimum 12 hours every day - in one year I have took it apart only one time - to be sure everything OK or not and add a bit grease (I use ISOFLEX NBU 15) and the only thing what was needed to replace bit later was motor bearings - I was lazy to replace these bearings direct when bought this used Kontronik Tango from ebay.
Many peoples are thinking that high speed spindles are something about mystic - yes, for me also if it need to be able for automatic tool change - but just high speed spindle - it is simpe thing. And Im far from it to be named as master of machinings, Im very modest machinist ;-)
Regards,
Herbert

praetor
06-11-2008, 04:08 PM
what size bearings do you suggest? Your the designer and builder so I would rather follow your system. I would need the bearing size/dimensions. Also, how was the cone put on? is it a tight fit on the ER tool? or is it screwed in somehow?

Thanks.

Herbertkabi
06-11-2008, 07:15 PM
Bearings for really good high speed spindle I prefer only angular contact Super Precision Bearings, expensive but you can find from ebay too. Searched ´super precision bearings` you will find different brand names mostly from ebay Shops... not cheap but then searhed these brands and names you can find much more cheaper ...
***I dont know shank diameter of your ER16 extension*** diam. 3/4" or 20mm? ...
Or this: ER16 1/2" SS COLLET EXTENSION W/WRENCH ebay 160201209876?
Cone is hot-pressed, or you can make just tight fit and use Loctite - I have used both ways. My cone placed on the place where normally flat sides for key, instead of this key I use clamp you can see on my first photos. It saves room (distance between collet and first bearing) and yhis cone protects bearing seal, gives more rigidity as well as work as gyro - high speed spinning mass(wheel). When its pressed (or fixed otherwise) on to the shaft then it need to be on time more very precisely machined by all shapes and sides ( of corse ONLY shaft between two cones on the lathe or collet and cone ...) I use stainless steel and very sharp special inserts - if just steel then I think you have to go to grinding for finishing. All parts need to be done very-very precisely, you have to be very patient. Sorry, if speaking too much - I have no idea how expierenced you are - there is no place for compromise by tolerances. Even long sleeve on the shaft between bottom and upper side bearings need to fits and slide exact and outer side need to be over-machined on the shaft - its made from aliminium, but even smallest dismissive with rotating parts will cause unvanted vibrations. All what are on the shaft I firstly make workpiece with acurate face side and needed precision bore, then finishing on the shaft (shaft only between cones or using collet ... I really hope that nobody will try just with Chuck ;-)
Regards,
Herbert

praetor
06-11-2008, 09:46 PM
Thanks again herbertkabi for your info, I will stay with your specification and any info you would like to impart I will accept you are not tlaking too much but you are helping a lot.
I went to vocational high school to become machinist, when I graduate there was no jobs availabel at the time. My country (USA) was going through a recession so I work many jobs machine shops did not want high school graduate they wanted experience. I work many jobs no machine shop jobs but I do machining at home for hobby and a little for private work. I can work good tolerances (.001-.0003) But i practice to make better.

Herbertkabi
06-26-2008, 04:30 PM
Finally ER11 extension shaft received today afternoon. Oh dear - ordered May 22, received Jun 26... used expensive enough courier service for shipping from US ... I have been in troubles with Fedex before too. But OK - now I have all parts I need, cone is already pressed on to the shaft and remachined by all surfaces. End of this week I will mill with new high speed spindle. Water cooled because I like silence when working in my small and modest workshop.
Regards,
Herbert

Herbertkabi
06-27-2008, 12:19 PM
Spindle is ready now. It is rigid and runs really smooth. Now I have to to mold silicon coupling, make some finishings of motor housing on the lathe ... then add cooling nipples, install the motor .... and thats all. Motor I will use not exact this selfmade one on the photo - I built another one too, looks near the same but bit shorter, it runs on my test stand right now: 24V, 2,8A -> 25kRPM, 6A -> 50kRPM, 8A 75kRPM ... seems I will not need more than 50KRPM, commonly 25k....35k, up to 50k it runs quiet because no ululate of fan. German GRW 1/2/001 AC1 TA super precision angular contact bearings have 86.000 RPM of Limiting Speed when oil and 76.000 when grease.
I hope you understand how bearings preloaded - spring gives preload between upper and lower bearings, three axial screws on the end-cup (coupling) controls preload of bottom bearing pair BACK to BACK. Cup itself is(coupling) fixed to groove on the shaft with three radial screws.
"Back to Back" pair - there one very thin precision fastener I added beween outer rings ...
Yours in Service,
Have a nice time,
Herbert

ViperTX
06-27-2008, 09:53 PM
Herbert, nice work. Any information on where I can acquire one of those motors. Oh, almost forgot and the motor driver.
Thanks, Paul

Herbertkabi
06-28-2008, 03:20 AM
RC stuff - I have told about several times. You need to know RPM/V (kv).
For example my previous spindle uses Kontronik Tango 45-13, (kv 1320 rpm/1v by data), using 24V it makes in fact nice 33k rpm, Controller also rc stuff, as well as servo tester (pwm gen.). RC motors/controllers are very powerful - 250W ....2500W - current more than 100A - you will use only fractional part of, when I mill with full speed using 3mm endmill then Ampermeter shows only few Amps , when 6mm endmill and heavy milling - even then visible current (you dont see pulses :-) never more than 5...7 A max (Kontronik Tango). You have to think about rotor diameter (and lenght) when choise about.
There are smart people - rc controllers have governor mode (heli mode) - its possible to set up for constant speed , irrespective of (or pending about) milling load - then amp.meter will show bit wide span of current change.
Some China made motors are also very good (when water cooling (I can let you know from where I bought)). I used only their Rotor because full motor bought cheaper than replacement rotor costs from Lehner, Hacker .... You can buy from eBay. Motor bearings I replace for best of hybrid ceramic ones even when brand new motor.
Kontronik, Lehner ... are slottless motors - no cogging, Plettenberg, Neu ... are slotted motors - you feel cogging when you turn rotor by hand. These two mentioned are also very-very good motors, especially Plettenberg has well balanced multipole rotor.
Depend about Voltage you use - always first af all you look voltage/rpm Kv of motor. Kv multiply V = no-load RPM = appr max mill speed.
Regards,
Herbert

Herbertkabi
07-10-2008, 05:58 AM
OK - although no palpable interest about my spindle - it works well. Max RPM near 50k, but too noisy then, I use it up to 37kRPM, most of all 25...35 kRPM.
Up to 10...15 kRPM its even too silent - it runs or not - need to beware with fingers. Perhaps I will take it apart few times more - some rotating parts I need to balance more precise. Universal cooling system works great for motor as well as for milling. On the pictures RPM is not high, ca 11.000, I have removed my special screen (used T-shirt material ;-) and I dont want to blemish my camera.
Regards,
Herbert

Jayson
07-12-2008, 08:57 AM
Hi Herbert
I applaud your work. I have been trying to build a high speed brushless spindle for quite a while and have been unable to find a suitable design. Your design is great. Can you recommend a brushless motor to use for this design?

Thanks,

Jayson.

Herbertkabi
07-12-2008, 10:47 AM
Depend what you want to cut, what size endmills, what you planned for shaft .... Many brushless motors are good. Most important is KV ( RPM per 1V). For example I use 24V - then for ca 48.000 RPM KV must be 2000. When you use 12v then KV must to be twice higher - 4000 to get 48k RPM of end speed. And current will be twice higher too then twice lower voltage. You must to know how you want it cooled - air or water. Not all motors are easy to make water cooled. Second thing you need to know is Rotor diameter and lenght - torque.
Motors you can buy from eBay when cheap or direct from Shops - mostly expensive, but from China you can buy very cheap brushless motors good for water cooled spindles, look at hobbycity.com. I have bought several types and cant tell much bad words about - for those money these are super! (of course bearings need to be replaced for the best ones - is the first thing you do). My first high speed spindle motor I bought from US ebay - Lehner 1930/8 - 50.000 rpm. Kontronik inner-runners are good too, especially special designed Kontronik Tango - very good motor up to 30k...33k (I used 45-13).
Plettenberg HP300 seies - VERY GOOD for high torque up to ca 25k RPM (NEU Motor near the same). Plettenberg HP370 series are good for large spindles up to 20...25K. Lehner 22** series are good ( up to 50K).... very many motors ...
End power of these motors are in kilowatts but you do not need to think about - mostly when used as spindle motor the current will be only few ampers up to 10 or 15 when some kind of heavy cut - but you have large reserve!
Not all spindles I have built have separate motor (with coupling) - some motors I have installed direct on to spindle shaft. Then a bit more works need to be done, sometimes rebuilding of all motor or even all motor self built. One thing is clear for me - it is very hard to get (selfmade)rotor well balanced when RPM is higher than 20k.
Next Spindle I started will be big one - will use Erickson DA-100 straight shank collet chuck, motor is fully selfmade 12 pole rotor (d-53mm x 30mm) 27 slots stator made from SMC, this motor is 100% my design - like the same does not exist.
Speed I will use is not high - up to 10.000 max - but smooth run even lowest speed and huge torque - it will be an special spindle for additional axis of my milling machine ... something like lathe spindle ;-)
Cheers,
Herbert

praetor
07-15-2008, 01:00 PM
That's a very impressive spindle Herbertkabi, this is the type of spindle I want to build for myself...unless of course you want to sell that one you have...:D.
So you use it for RC stuff, pretty neat! Maybe i should try that sometime.

Herbertkabi
07-16-2008, 05:57 AM
That's a very impressive spindle Herbertkabi, this is the type of spindle I want to build for myself...unless of course you want to sell that one you have...:D.
So you use it for RC stuff, pretty neat! Maybe i should try that sometime.
Have told before - I do not spindles for sale, only closest friends have got it like gift. I can not give any warranty when its made by me - Im very modest machinist - I can see very experienced/practiced/versed members of this forum who can do much more better ones.
I have got some privat messages where wonder why I spend a lot of money for very expensive super precision bearings, collet chuck ... motor, driver ... - Oh dear! - Why you build your cnc mill yourself ? - I can ask as well. For me its not about the money, I can buy what ever I want, no problem ... but I like to do myself - even my house I built myself, more than 20 years ago I built 40kg Induction Furnace (for Bronze) - when I started I had no idea how it works, there was no Internet at this time from where to study... but I did it successfully.
I do show my High Speed Spindle just as respect this public, I hope that when I have gave something, some ideas from myself - I can ask some helps or advices from anothers. To be honest - I need much more advices than I can give myself to anothers.
Regards,
Herbert

praetor
07-16-2008, 07:26 PM
Herbertkabi, I don't want to insult the modest machinist but may i contact you privately on here (cnczone.com) for pricing? I am pretty sure you'll be satisfied with the pricing I am offering. I don't mean to offend you at all, but the sooner I can get a spindle going on my machine the better. I use my machine for engraving and making plaques and or medals and your spindle seems to fit what I need. I would build my own according to your plans, but if I can get one in a couple of weeks it will really put me ahead of time. I have researched your design, along with my friends and they say your design and the precision you have on your spindle would more than suffice my use...so, again, if I may contact you privately I am sure you'll be satisfied by my price.

Herbertkabi
07-17-2008, 04:21 AM
1.) Try to find as better as possible Collet Chuck extension - as cheaper as possible.
Every type could be OK, every shank diameter could be OK - Shank diameter ---> Bearings. If you have access to good Shaft-Grinder - you can resize some used collet chuck to needed diameter (ID of bearings you found. But this Shaft-Grinder must to be very experienced/practiced/versed !!! Unfortunately very often they are not.
2.) Try to find as better angular contact Bearings as possible - as cheaper as possible.
To engrave medals you dont need 1...2 kW motors I used. Even for my works Im doing my last motor is too powerful, but it does not matter for me. I hope I can tell you about near every motor you have found - is it OK or not - you have only to ask about.
Summary: you can keep your budget much more lower level.

I do not sell my spindles! I just gave some ideas for people who like to try.
I have Kavo 4025, I have Elte 350w, I have few more HF spindles I have bought from eBay for study how they are made - I dont use these asynchronous spindles - I like my DIY BLDC spindle.
Regards,
Herbert

Herbertkabi
07-17-2008, 11:29 AM
OK - two sides - completed Spindle side and completed Motor side, I dont want to take it more apart than to half right now - it runs very well, bearings are greased-preloaded.
Spindle side - 1360 g = 2.99 lb
Motor side - 780 g = 1.72 lb
Too heavy weight? I did it especially, larger mass gives more stability against vibration.
Outer diameter of Spindle side is 43mm - its common spindle diameter in Europe. But any diameter you like is good.
My first spindle I made years ago I used Aluminum as main housing.
Inside this housing was "spindle side" made from Bronze (just bearing holder) and motor from another side, simple T-coupling between and nothing more.
Shaft was also ER-11 extension, hollow shaft mode, but bearings I used 4 x R1212 thin section bearings on the lower side and 2 on the upper. These are cheap bearings even when ceramic balls. Light preload between upper and lower side and you can mill/engrave your medals long time as old man ;-) I did run this spindle with up to 50k rpm, motor was at first Lehner 1930/8, but it wants to go too hot without water cooling, I changed it to 4-pole iron core older German made Icarus, speed was now lower but enough anyway - 35k rpm. As I have told - there is huge choice of motors and controllers, as well as you can use what ever for Shaft, you can use some original shaft from broken spindle, to use collet extensions, straight grinder shafts ... you can order from machine shop especially made for you shaft as well ... without collet at all - like simple tool-holder 1/8" bore ... All starting from SHAFT - all the rest depends about , what bearings, what ever else ...
Regards,
Herbert
PS:
When you have one time tasted super precision bearings then you never want to use something else when we are talking about high speed spindles.

praetor
07-17-2008, 12:29 PM
I just need a materials list, if possible. The kinds of metals you used for your spindle, I have Cold rolled, Hot rolled, stainless steel, and aluminum stocks. I want to begin building this spindle this weekend. Also do you have measurements? What is the degree of angle on the cone?
Thanks, Herbertkabi for encouraging me to build my own using your plans/ideas.

Herbertkabi
07-17-2008, 06:47 PM
Material list? Spindle housing and Cone - Stainless steel, round, I just bought from German ebay edelstahl 50mmx300mm piece, 1.4301-X5CrNi18-10 but its not so important, Cone angle 45 degrees ... also more like your taste about visuality ;-)
Housing/sleeve for upper bearing I made from stainless, despite was planned from Bronze. Fixator/cup for coupling mother side - 7075 aluminium as well as Long Sleeve. Preloading dish between fixator and upper bearings - Stainless steel. Then you need to make spring under upper bearing ... Im not sure you can find exact size waved spring washer - you can change this - many another ways. Force of spring is critical of course. 0.05 and 0.1 mm washers (or any thin thicknes) - hard to find right sizes - Im making myself from 0.1mm and 0.05mm special brass sheet (patent ;-) very good quality! - I need to show it separately. It is meaningless to give dimensions when I dont know exact type and sizes of shank you will use as spindle shaft, the same story with bearings ... all the rest depends about ... for example some super precision bearings does not need any washer between outer rings when Back/Back scheme (my lower bearings) - GRW 1/2/001 AC1 TA I use - there its necessary ... and so on.
Herbert

Jason3
07-18-2008, 01:35 AM
Hi all. I'm sure someone else besides me has considered buying something like the NSK spindles without the motor, and adapting a model aircraft motor to drive it - in the manner of Herbert's nice design.

Does anyone know of anybody who has successfully done it? It would save the effort and avoid the skilled machining required to produce housings and fit bearings precisely, and although it would cost more than the do-it-yourself option, perhaps it would suit someone less skilled (like me!) in machining, or with less time.

The motor would need an adaptor to screw onto the NSK spindle and the drive shaft of the motor would need to be machined into a '+' shape, which seems easy enough. It would also allow for painless auto tool change if one selected a spindle such as this:

http://cgi.ebay.com/NSK-E3000-SERIES-AUTOMATIC-TOOL-SPINDLE-NR-5041E-ATC_W0QQitemZ330253719588QQcmdZViewItem?hash=item330253719588&_trksid=p3286.m14.l1318

Or, a cheaper one:

http://cgi.ebay.com/NSK-E3000-SERIES-SPINDLE-NR-2532-0-98_W0QQitemZ230272409403QQcmdZViewItem?hash=item230272409403&_trksid=p3286.m14.l1318

Anyone have any thoughts?


Jason

Herbertkabi
07-18-2008, 06:21 AM
I have tried by this way. Have used several Factory made spindles found from eBay, just added motor via coupling or installed rotor direct to the end shaft. The last mentioned is very hard because balancing - but sometimes did pan out successfully.
I have few more suchlike spindles I have bought, waitings rebuilding.
First you have to take it apart and to look what is insida ... often you find:
*sui generis sizes of bearings are near worn-out or there are just common cheap ones and you cant find same size precise angular ones.
*unique type of collet - it looks like similar to ... but it is not and you never find.
*sealing system is abrased ...
If (and mostly;-) you cant find exact size new bearings - you have to resize or housing or shaft or both :-( By my opinion I get more precise thing when started from "0" than resized existed housing - but you Boss - Im not high master of machinings.
Installed unique collet, the only one you have installed is for example for 2.2mm shank endmills ...
You cant find endmills, you cant find better size collets ....
You have exact the same start point as when starting with new one + rotten humor.
Do you like to see my "store" of aparted spindles? When bought for $10..20 then OK, but some stupid things I have bought for ... oh dear!!! ... better to let it be ...
But ok - some spindles I have rebuilt to be motorized very easy and they works well.
Regards,
Herbert

bilinghm
07-18-2008, 09:17 AM
Here are several high speed spindles that are being marketed by Keling.

http://www.kelinginc.net/CNCSpindleandController.html

Many of us use Keling's electronic components. These might be very good spindles.

praetor
07-18-2008, 12:29 PM
These are very nice spindles (pricey, but quality) but Herbertkabi's design is very sound and comes in under 5lbs (including motor) and by his accounts seem robust for it's size and what I need to do, but the kelinginc.com spindle is very, very interesting to me. it would make for a very good gantry mill, maybe a 5 axis build. Thanks.

Jason3
07-19-2008, 12:13 AM
Do you like to see my "store" of aparted spindles? When bought for $10..20 then OK, but some stupid things I have bought for ... oh dear!!! ... better to let it be ...
But ok - some spindles I have rebuilt to be motorized very easy and they works well.
Regards,
Herbert

Herbert - yes please! Would really like to see pictures of the spindles you have dismantled... I have a Kavo 4029 that needs new bearings, and a 4052 with a bent rotor but I haven't yet built up enough courage to try to open them :( It's a shame, I have frequency convertors for them both, but the spindles need rebuilding and I don't want to pay the price for the factory to fix them!

Regards,
Jason

whiskeykid
10-01-2008, 04:25 PM
Herbertkabi, I have a question. Do you pack the bearings with grease prior to assembly, or is there a grease nipple I'm not seeing to lubricate the bearings? What is the advantage of greased bearings instead of a sealed oil bath design? Don't you have to re-pack the bearings with grease occasionally? I have an ER20 collet extension that I would like to build a spindle around, your design looks great.

Thanks for any help you can give.

Herbertkabi
10-02-2008, 03:59 AM
Herbertkabi, I have a question. Do you pack the bearings with grease prior to assembly, or is there a grease nipple I'm not seeing to lubricate the bearings? What is the advantage of greased bearings instead of a sealed oil bath design? Don't you have to re-pack the bearings with grease occasionally? I have an ER20 collet extension that I would like to build a spindle around, your design looks great.

Thanks for any help you can give.

hi,
I do grease when assembling. No nipples but of course you can add nipples as well if you feel necessity. I have disassambled/assambled my spindles after few times anyway - did like to see how it looks ... it looks well and no matter to add new grease. Now I go to disassambly only when felt strange noises or any else deflexion. When ready built then few times you will need to take it apart again and again ... its not hard to do because you made it yourself .
Nothing happend with my 45 krpm spindle (water cooled) in past 4 months and my 33 krmp spindle (air cooled) runs well more than year.
It runs right now as well, I do hear it ;-)
I use ISOFLEX NBU 15 (Kluber).
Cheers,
Herbert

MechanoMan
04-12-2009, 04:28 AM
Well I've got a Taig with a 1/4hp 3450RPM motor and like a ~1:3 pulley ratio at best, so around 10k RPM at the spindle.

I've only used solid carbide so far (got a great dealer in Round Rock here).

Especially the smaller bits and engravers must have high speed. The tiniest engraver I was using has a tip like 4mil. So the tip's surface (pi*diameter*rpm) is only rubbing against the material at 2in/sec at 10,000 rpm. This limits the ipm speed and finish.

I was trying to run 2-flute 1/8" carbide endmill into aluminum bronze and having power problems with high rates. I swore at times I saw the carbide bend. I broke 4 bits experimenting, but none flew out of the work much less at a dangerous speed. I could hear the motor slow down a bit. This is probably due more to the mistake of running it off an extension cord; there's no plug in this part of the garage and I have had trouble installing one but it's high on the to-do list. In fact the lamp dimmed so I know the extension cord was responsible for dropping the voltage some.

I would like the ability to get more speed and more torque. I'm also concerned though about the maximum RPM the spindle bearings can take. Also the Taig belt drive may not take it- without an idler wheel, I can see that belt is swinging "out there" the highest speed and sometimes vibrates, even though I try to maximize the tension on it. And also at high ratios the belt can potentially slip on the smallest pulley (which would be the spindle) when torque increases. In fact at a stop, even when I have the belt tensioned as high as I can by hand, I can hold the spindle stopped by hand and turn the motor pulley by hand and it'll slip over the spindle pulley. It's only able to resist a few ft-lbs of torque so unless I can switch to direct-drive with a super-powerful motor of a much higher RPM I'm not sure that increasing the hp won't just result in slippage, a burned belt, and a broken bit as it drops from the needed RPM.

I did see there's a 8000-2400RPM 1.5KW (2hp) spindle with ER11 collet on eBay for $281. They've got a 3KW water-cooled one too!
Also there's this Kress 800. 800W, aircooled, 10,000-31,000 rpm, and that's only $183. The thermal shutoff NEEDS to be rewired to the E-Stop!
These things are DC motors so they can be controlled electronically, but the air-cooled ones are screwed at lower speeds. They can produce lots of torque, but the fan isn't moving enough air to keep it cool so it can burn up right there. Unfortunately a small computer fan ducted in there isn't gonna do the job. Significant CFM at a fairly good pressure are needed so it'll need to be a pretty good blower (which isn't rocket science territory but it's not trivial either).

Herbertkabi
04-12-2009, 05:45 AM
http://www.cnczone.com/forums/showthread.php?t=72691&page=2
#19
Final result was up to 8600 rpm with 24V, (12.900 when 36V).
Its silent, high torque, high efficient ...
RPM regulates via Servo Tester,
When smart enough in electronics then add circuits and fully controlled/independent RPM is not a problem.
cheers,
Herbert

Riceburner98
04-28-2009, 03:44 PM
Well I've got a Taig with a 1/4hp 3450RPM motor and like a ~1:3 pulley ratio at best, so around 10k RPM at the spindle.


Just noticed the Taig mention and thought I'd post my experience lately..

I've been running my stock Taig spindles at 10k (by specs, not measured) for a little while now. After maybe 10 - 15 hours of machining, the bearings in both the standard Taig spindle and the ER-16 Taig spindle were shot. Still useable, but you can hear and feel the damage. They never got hot (barely warm) to the touch. They're just not that good of bearings. I replaced the bearings in the standard spindle with angular contact ones, but think I got the preload wrong and they lasted about 15 minutes before the grease vaporized and the bearings were shot. :(

I bought the Wolfgang mini-spindle from eBay a few months ago, but the motor pulley was loosely held on there with some oozing Loctite and wouldn't spin. Got it wedged on with a "shim" / sleeve (no setscrews in it..) but it doesn't appear to be doing near 10k rpm, let alone more.. I need to build an optical tach or buy one, hard to tell RPM by comparing it to the Taig. Maybe it really is going that fast but doesn't seem it because it's not as loud...? Either way I need to do something. The motor looks like a small vacuum cleaner motor and smells way too much of ozone from the brushes. I did buy the motor just to "get me by" until I figured out a new one for it, so no huge loss there. The spindle itself looks to be of nice quality.

I also looked at the NSK spindles and thought about adding my own motor, but haven't spent the $$$$$$$ yet. My "new" machine design has changed at least 100x in my mind, so I haven't settled on "small high speed" spindle on a light duty frame, or super-overkill spindle on heavy duty frame... I had planned on just using the Taig spindle with DC treadmill motor, before realizing how fast 10k RPM kills them.

If I were good I'd try and replicate Herbert's spindle, but my little Taig lathe chatters on aluminum, never mind stainless. :)

devincox
05-07-2009, 11:33 AM
This is a wonderful thread packed with great info. My thanks to the contributors.
However, after reading some of the info here I needed to better understand the designs presented and so went surfing. I came up with a link that I feel is relevant to the thread and wanted to post it here.

http://www.mmsonline.com/articles/high-speed-spindle-design-and-construction.aspx

Devin

red_glass
09-01-2009, 06:10 AM
I just wanted to say thankyou to Herbert for sharing his designs, experience and humility. I have read the entire thread from end to end and found it inspiring on several levels.
Could someone clarify the way the "Brushless Speed Controlers" is controlled by mach3 etc what I mean is how does the controller know how fast to go? Does it use a variable control voltage?
Also is there any reason you could not attach an optical encoder to the other motor spindle as some of the "inrunner"? brushless motors have dual shafts for fans connected to other end.
I am very new to this area and have alot to learn but if we used an optical encoder couldn't we use a cheaper controller without governor function and use mach 3 to give precise speed/torque control?
Regards
Mac

Herbertkabi
09-01-2009, 11:28 AM
I just wanted to say thankyou to Herbert for sharing his designs, experience and humility. I have read the entire thread from end to end and found it inspiring on several levels.
Could someone clarify the way the "Brushless Speed Controlers" is controlled by mach3 etc what I mean is how does the controller know how fast to go? Does it use a variable control voltage?
Also is there any reason you could not attach an optical encoder to the other motor spindle as some of the "inrunner"? brushless motors have dual shafts for fans connected to other end.
I am very new to this area and have alot to learn but if we used an optical encoder couldn't we use a cheaper controller without governor function and use mach 3 to give precise speed/torque control?
Regards
Mac

These controllers use PWM for. Simplest PWM generator (or RC servo tester) then you can just control the motor speed (via pot.) I have covernor circuit my friend made it - it keeps any choiced constant speed when load changes, but my spindle does not co-operate with mill controls ... Im too weak in electronics - anyway it is possible.
I have now Mach3 control too ( X15-250 - bought from machmotion.com) but biulding my new 5-axis mill takes all my time right now - still I have not familiar with this nice stuff at all, just its waiting hes time on my table. Soon I start with wirings of my new machine - then will see.
cheers,
herbert

dfurlano
09-12-2009, 05:59 PM
I threw away several hundred dollars trying to get my mini mill spindle above 10k. High speed bearings, motors it was all a waste of time and money.

Major problem if you do not have access to serious tools which I don't so I wasted money buying services and parts that never really worked.

I finally just broke down and bought a real NSK high speed spindle and retrofitted it myself. Problem solved.

Up to 50k as it stands 30k with speed reducer to increase torque.

http://www.dfurlano.com/g1.jpg

http://www.dfurlano.com/g2.jpg

Riceburner98
09-13-2009, 12:25 AM
Nice! I've been looking at those... How does it sound at full speed? I figured I'd get by with the Wolfgang one from eBay but it was a waste of $. Figure I might as well spend the $ for a real one. Any personal experiences with it? Do you use 1/8 tooling, or just smaller stuff? (.01"?) What kind of feeds do you get with it? Inquiring minds... :)

dfurlano
09-13-2009, 03:36 PM
I have not run it at full speed but at 15k you can barely hear it running. For high speeds you should air cool the spindle. I have not used it enough to tell you feeds and speeds but I typically use .001, .003 or .005 pyramid cutters on wax and .012 to .016 straight end mills on sterling silver. From what I am told I can run these fairly high without cutter breakage.

Dan

Riceburner98
09-13-2009, 05:53 PM
Nice! :) I use my current Taig spindle with .01" endmills at 11k and it sounds like the bearings are going to explode. My question: how do they cut the flutes in a .01" endmill???? Love to see that machine at work!

Is the little air tube at the top of the spindle for air cooling, or is that for something else? (like air bearings?) My compressor is so dirty I'm almost afraid to use it with an NSK without like 5 filters inline..

Good luck with your cutting!

dfurlano
09-13-2009, 06:07 PM
I have no idea what machine cuts a .01 endmill but this is where I buy them:

http://www.bitsbits.net/index.php?main_page=product_info&products_id=332

Yes there is an air line for cooling and a power line into the top of the spindle. You can buy a special filter for the NSK it does have to be oil and moisture free air. Currently running a .03 ball nose end mill at 15k and 10 ipm. I could most likely go faster but I don't want to push it.

Dan

dfurlano
09-17-2009, 07:05 PM
short video.

http://www.pencraftsman.com/spindle.wmv

Riceburner98
09-18-2009, 05:22 PM
Wow, that's pretty silent! Thanks much for the video!

MechanoMan
09-23-2009, 06:03 PM
I'm still of the theory that the German water cooled spindles on eBay would be a great idea. They're the same ones Keling is selling, just a WC version from the same mfg. Actually, if you need a filtered, dried, compressed air source, WC is less complicated that that. Just add a cheap PC water cooling pump and radiator and the spindle should run extremely cool and quiet. According to my calcs, the dissipation required is well within the capabilities of a PC water-cooling radiator.

Herbertkabi
09-24-2009, 03:03 PM
Perhaps you can get some ideas and parts from http://www.usovo.de/shop/
Cheers,
Herbert

praetor
10-22-2009, 09:11 PM
Hi there Herbertkabi, I was looking over your posts, again, and wondered if you can give some dimensions to the homemade high speed spindle featured in this thread. I know it may be an old post, and you may not have this in your possesion but I'm having trouble determining the dimensions to the above high speed spindle you made.

RotarySMP
10-23-2009, 06:40 AM
Hi Herbertkabi,

This is one of the best threads we have had here on CNCZ. It really helps that you post so many pictures, when explaniing your work. Thansk.

Your method of preloading the lower bearings through the upper bearing inner race is excellent. Thanks for explaining it.

I have a set of ER-16 collets (Sherline mill spindle cartridge), so I am looking at an ER-16 collet chuck with a 20 DIA shaft. For the stuff I need, 3-6mm milling in aluminium and steel will be most common.

I have a few questions:
1/ In post #72 you talk of remachining the collet chuck all over, but in #82 I think you are saying that this is not necessay. In your experience, are these chinese collet chuck shafts normaly dimensionally accurate enough to mount P2 Angular contact bearings without regrinding the OD? (There are some nice P2's on Ebay Germany).

2/What type of bearing do you now use for the upper bearing? I see you make a floating mount centered with O-rings.

3/ You preload the upper bearing with a home made wavy washer. You mention in post #85 that you might post a "how to" thread describing how you make these. I would really appreciate if you could. You have stated that the wavy washer is made of 0.05 -0.1mm Brass sheet. I would have thought this this brass stock would have little spring back, and would flattern and provide little or no spring force? Am I confusing the shim to preload the two lower angular contact bearings with the spring for preloading the upper spindle bearing? What force in N are you aiming for on the upper spindle bearing?

4/ In #75 you said you could give us some links of where to get chinese motors. In #78 you pointed us to Hobbycity.com, thanks. I checked their website and it would seem that their KD36-74-15XL would be most appropriate to what would like to do. Do you have any experience with this motor? If you have any other good links to chinese or hong kong web shops please post them.

5/ All I know about speed controllers, I have learnt in this thread :). Looking at Hobbykings selection, it seems most are limited to low voltages, but I will need one which will handle about 28V. It looks like LiPoly is about 3.8Vper cell, so i am looking for a controller which can handle 8 cells. The Hobbyking SS Series 60-70A ESC would seem okay. Is there any other parameter that needs to be considered? Am I missing something here?

6/ What else do I need to get this motor running with this speed controller? As PSU, I would make a simple unregulated 28V 500W PSU with a big cap. I see programming cards available for most other brands of speed controller but not for Hobbykings house brand. Do I need one? Having governor mode activated sounds practical.

The Speedcontroller has the same interface with the Rx as a servo. Looking at http://www.epanorama.net/documents/motor/rcservos.html, it looks like this is a PWM interface, but only runs between 0-4&#37; duty cylce on the signal pin. Mach 3 can directly output a PWM signal, but I don't think it allows control of the pulse width between 1ms (off) and 2ms(full), rather it controls the line between 0 and 100%. I'm sure it would not be differcult for someone with more electronic knowledge than me to make a widget to convert this Mach 3 0-100% PWM signal to a 0-4% for the RC Speed controler . I'd probably just use a Homann spindle speed control board to convert 0-100% to 0-10V, and build the widget in the above link to interface that with the speed cotroller.

Herbertkabi
10-24-2009, 07:46 AM
1.) I have not met bad made China chuck, are as described.
The only thing I do is hot pressed cone (after that remachined), and perhaps some gooves ...
2.) my first spindle where floating upper bearing I used deep groove bearing, later changed to angular - was much better. I use only super precision angular contact bearings, only once bought from factory, most of from ebay, brand new but much cheaper. Sometimes I do replace steel balls -> ceramics ... grease I use Kluber - again from eBay.
3.) First wave washer was selfmade, yes, now I have some factory made as well. But instead of mentioned - also I do use small spiral springs with plugs and circlewise bored small holes on the "piston" and on the inner edge of housing.
When waved washer then its made from ca 0.3mm steel, waving is hot-wormed and adequate threated.
Yeah - pressed-packed 10...20 layers of 0.05 -0.1mm Brass sheet - there I do machine (milling machine) set-up washers ;-)
4.) I just rebuilt this Chinese motor ... to be honest I do rebuild even Lehner or what ever motors :-) I do build myself as well - from A to Z - not because to save the money ... its just my beloved area ... when used the best possible materials and custom balancing service then cost of selfmade ones will surelly exceed any seen price.
Chinese or not chinese - the right size, Power, Voltage, kV, max rpm and VIBRATION(!!!) are what you need to check . And bearings must to be replaced to the best of ones. When slotless motor like mentioned chinese - then water cooling surelly necessary.
5.) LiPo (3-6 cells);NIHM (8-18 cells) - up to 24V,
ESC you need you must to look from "high voltage" section, at least LiPo (2-10 cells);NIHM (6-30 cells) Max Voltage : 42Vdc
Although the Amp-meter shows 3...5...9A when milling - I use at least 25A ESCs ... even 100A ... I have a lot of controllers because years of RC activity ... but anyway I have bought and used newest Asia made ESCs with success.
6.) Just connect motor, connect Servo-Tester to motor (when ESC has no BEC, then you will need external bec to feed servo tester ...) -> power supply. Or go to any rc-forum and ask - my Englisg is too wooden (DIY ;-)
EBAY offers a lot of RC bl speed controllers and motors, new and used - I have never despised used stuff - risk is near nonexistent but saved money notable - saved 50&#37;, sometimes you can get 200$ stuff for $20
I have bought different stuff total more than 1600 times from ebay ;-)
http://modellbau.shop.ebay.de/RC-Modellbau-/9153/i.html?_nkw=brushless&_catref=1&_fln=1&_trksid=p3286.c0.m282
http://toys.shop.ebay.com/?_from=R40&_trksid=p3907.m38.l1313&_nkw=brushless&_sacat=220

cheers,
herbert

RotarySMP
10-24-2009, 01:41 PM
Thanks for you response Herbert.

So you use a pair of AC bearings preloaded back to back at the bottom, and then another AC bearing lightly spring loaded at the top. Wouldn't a needle roller bearing be better for the top end? What did you not like about the performance of the spindle with the deep groove ball bearing at the top?

Thanks for clearing up that you are using the brass for shims to preload the bottom AC bearing pair, and are using thin steel wavy washers to preload to top one. Where do you buy the spring wavy washers?

Have you ever made a low speed spindle? My current milling spindle is a Sherline ER-16 and it is only good for 2500 RPM (with standard preload) or 10K if you back off the preload a bit. It doesn't have a pair for preloaded AC bearings at the spindle end.

I have ordered a pair of 7204 P2 bearings and a C20 ER16 150L coller chuck. Once the chuck arrives I can measure it up and start designing my spindle.

Herbertkabi
10-24-2009, 04:44 PM
Thanks for you response Herbert.

So you use a pair of AC bearings preloaded back to back at the bottom, and then another AC bearing lightly spring loaded at the top. Wouldn't a needle roller bearing be better for the top end? What did you not like about the performance of the spindle with the deep groove ball bearing at the top?

Thanks for clearing up that you are using the brass for shims to preload the bottom AC bearing pair, and are using thin steel wavy washers to preload to top one. Where do you buy the spring wavy washers?

Have you ever made a low speed spindle? My current milling spindle is a Sherline ER-16 and it is only good for 2500 RPM (with standard preload) or 10K if you back off the preload a bit. It doesn't have a pair for preloaded AC bearings at the spindle end.

I have ordered a pair of 7204 P2 bearings and a C20 ER16 150L coller chuck. Once the chuck arrives I can measure it up and start designing my spindle.
hi RotarySMP,
Needle bearings are not for even 2500 rpm, at least not for me.
At that you need axial preload for bottom bearing or pair of bearings,
And at the same time this upper one must to keep spindle shaft rigid and very stabil. When "normal" deep groove bearing then it did work well just month maximum for me ... you can hear it and you can see on the sample you are milling ... and then it will come more worse and worse up till you can not use it anymore. At that it will ruin your nice and expensive bottom bearins
Perhaps you have some kind of mil.spec ... ceramic ... its possible, but for
me was simplest to use AC bearing. I have seen interior of several better-known and similar size spindles - all they use only AC bearings on the bottom and upper side as well.
I use different spindle bearing schemes, not every time like you described above. For small high speed spindle one AC bearinh on the bottom and second on the upper side works well too, but this floating preload system I like very much, if used good bearings then once precision set-uped you can use it years without needs for fine-tune. On my router similar spindle has been in work bit more than two years, 30.000 rpm, every day several hours minimum. Somewhere in May I detected some strange noises :eek: I took it apart but all was very good, clean and sufficiently greased - cause was about Motor bearings :( I have told before - dont save the money with motor bearings, I did it (replaced), but seems not to the really best ones.
My latest spindles where all are in the same shaft there no such kind of problems, but much complicated to build (!) when we are speaking about high speed 20k ... 30k and higher - because balancing :-(
Sherline spindle I have rebuilt to direct drive total three, the last one did for myself. When original deep groove bearings then 6k...8k rpm, someone in cncz spoke it runs OK up till 12k ... Im not sure about ... at least my brand new Sherline spindle I especially bought for experiments did not like much higher than 8k. Now when replaced to adequate AC bearings (1+1) I have tried up to 18k RPM. Perhaps Im not right about ... may be ...
Im not any end most clever dick about - many have different opinions and better understandings, many members surelly know much more about ...
Just my own how-know, my opinions based on my modest experience.
Regards,
Herbert

P.S.
FAG Spindellager Schulterlager B71904C.T.P4S.UL Artikelnummer: 170396466022
you can find more ...
B71904-C-T-P4S 20 id / 37 od / 9 h / 38.000 rpm in grease ;-)

RotarySMP
10-25-2009, 04:17 AM
Hi Herbert.

For a lower speed spindle, one could use a needle roller at the top and still preload the lower AC bearing pair through the upper inner race. I guess I need to decide whether I'm building a low speed or a high speed spindle before I start :)

I often use a small flycutter or a circular saw blade in my mill, so slow speeds are also attractive. Maybe I need to make two spindles, and make interchanging them easy. I have been thinking about using an RC motor to drive the spindle through a belt drive reduction, as then I could also keep the Collet chuck spindle through hole open for using a retaining bar or even an auto tool changer.

My mill would be lucky to run 12H a month at present. I is at a friends place an hour from home.

Thanks for the Tip on the FAG bearing. It is great for the buyer when people put little information in Ebay. I was looking for a 20mm ID AC bearing, but I missed this.

This is the pair I have bought for the bottom of the spindle:

Zwei St&#252;ck Spindellager DKF.: A7204C.TAP.P2.UR

FAG-Bez.: B7204C.TPA.P2.UR
Ebay 330318484908.

Herbertkabi
10-25-2009, 07:17 AM
hi Mark,
Yes, I know DKF (GDR), have bought few sets from `Tusnelda44` for another projects,
Outer ring of your bearing has full shoulders, inner
ring has one shoulder cut away ... see the photp ... do you know the angle?
I have never used this type of angular bearings for high speed milling Spindle.
Perhaps good, but I prefer AC bearings where inner ring has full shoulders.

I use small fly cutter as well - selfmade - Radius 10mm, 7mm shank, 7075,
ca 20k rpm, even up to 30k, makes perfect surface.
Actually VCGT 130304FN-ALU inserts and have more similar fly-cutter for different inserts.

cheers,
herbert

RotarySMP
10-25-2009, 03:10 PM
Does that fly cutter howl at 30K rpm?

I can't find the specific for the A7204C.TAP.P2.UR, or the equivalent FAG, but Fag's replacement is a 15&#176; contact angle.

Herbertkabi
10-25-2009, 07:05 PM
Does that fly cutter howl at 30K rpm?

I can't find the specific for the A7204C.TAP.P2.UR, or the equivalent FAG, but Fag's replacement is a 15&#176; contact angle.

Yeah, Mark, I dont believe you will find equivalent, what ever they made in DDR, all was concerted with Moscow ;-)
Under the name DKF W&#228;lzlagerwerk Leipzig, the company became world-wide known from 1955 to 1990. In 1990, the company was incorporated in the FAG group. The company Kugel- und Rollenlagerwerk Leipzig GmbH was reestablished in 1993 after execution.

http://www.krwleipzig.de/english/produkte.php?PHPSESSID=b9bf6428002833fae68330e09c033c53

My fly cutter cuts very well, there will come some resonance near 30k and near 25k because I keep rpm below 24k. These inserts need to be as sharp as they are in new condition and sharp they are, bought a lot of via ebay.de ;-) Most of all I machine Aluminium, 7075 in majority, another alloys too and have tried brass as well. I use always Coolant. The only rule with this fly cutter is carefulness with Z axis, it likes to cut thin chip.

No, it does not howl.

cheers,
herbert

RotarySMP
10-26-2009, 11:33 AM
I hope those DDR bearings are good. This will be my first high speed spindle, so I see it as a learning exercise. If it turns out crap, hopefully I have learnt enough to make the next one better.

I was doing a bit more work on my ER-32 low speed spindle for the Frankel Deckel today.

http://www.wrathall.com/Interests/CNC_conversion/FrankenDeckel.htm

I picked up an industrial right angle gearbox ages ago, which looks like it will make a really nice massive spindle body.Found a piece of scrap 40mm Bar with a 20mm hole through it which was to be the spindle. I had already machined and polished the OD down to 35mm for a pair of 32007 taper roller bearings. Today I mounted the spindle with a fixed steady and set about cutting the M40x1.5mm thread for the ER 32 nut. I was going to follow this with roughing out the taper on the lathe (I'd grind the taper finished once it is running in it's own bearings).

Unfortunately such a thread is right on the limit of what I can cut with my converted mini-lathe. I was down nearly to depth (takes about 30-40 passes to cut this thread in steel on my lathe), when the work caught up and rotated in the chuck. I'd used aluminum beer can as a shim to stop the four jaw independent from marking the OD, and I guess it compressed and released the chuck jaws tension. I had it dialed in really sweet using my Verdict 1/10000" DTI, and maybe had left a jaw a little too loose when I got it running round.

Since I use a 1/rev spindle encode for TurboCNC, I should have marked the work with relation to the encoder so that it could be lined back up.

I'll leave it today, but maybe another day I'll have a go at trial and error with getting it back in the chuck, dial in round and running slow threading air cuts till get it indexed again.

Damn, I just realised that I forgot to bid on that AC bearing you sent me the link for. The auction has already finished. I'll have to keep an eye out for those.

Herbertkabi
10-26-2009, 07:34 PM
Yeah, nice and strong spindle, I like to use dusty stuff from my uppermost shelf - have acquired a lot of by style "perhaps in future" - and mostly this day will come surelly.

You need to be patient and try to search ebay by different ways - sometimes seller does not note full type-Nr of bearing or made mistakes ... or does not know at all what he is selling. After Spindellager I try FAG, Barden, SNFA , GMN, Timken ...etg
it takes time but saves money. And once found something I never forget to look at "Andere Artikel aufrufen" - have found wonder stuff !
Cheers,
Herbert

RotarySMP
11-15-2009, 04:11 AM
Hello Herbert.

I have received the ER-16 collet chuck which I will be using as a spindle. The shaft seems nicely ground and mic's at between 19.99 to 19.994 depending on feel (I am using a imperial .0001" Mitotoyo micrometer, and converting).

Since I have no information on the bearings, and the manufacturer is gone, I have no engineering data on those bearings.

The inner races of the DKF bearings are also micing at 19.994mm (to the best of my ablity to measure them, as I only have a set of cheap Chinese telescoping gauges, which seem to slightly retract as you tighten the locking screw, so I had to measure them about twenty times before I had a few measurements with consistent feel - Don't by cheap Chinese precision measuring tools every again Mark!!!!).

In any case, I don't have a sliding fit, and will have to press the bearings on. This makes the assembly a has to be right first time thing, as I can't see myself getting them back off again (at least not still P2 precision afterwards).

Were your bearings also a press fit on the spindle? If the nose of the spindle is shrunk or epoxied in place and then turned between centers, and the bearings are also a press fit, then I can not assemble, as I could no longer get to the screws which fasten the bearing retainer (orange in your model).

I would rather not have to put the spindle between centers and polish the diameter down by a 0.01 to provide a sliding fit, but was that what you had to do?

I measured thickness of the inner and outer races of the bearings with a good .0001" DTI on my surface plate, and they are the same within .0001" (~0,002mm).

What thickness shim/spacer would recommend between the outer races? What preload torque would you recommend I then put on the bearings through the inner races?

Herbertkabi
11-15-2009, 08:36 AM
hi Mark,
My bearings fit exact - means no pressing, no feelable slack.
You right - when pressed then necessary setings and fine-tunings near impossible.
I have polished the diameter down between centres on the lathe used fine sandpaper (with cooland ot thin oil) ... I do it per 20...30mm, when cleaned, tried and when OK, then next 20...30 mm up to the end. Like this you get better results, at that sometimes just this first part of shank is micron oversized.
Mh ... by remote its impossible to tell about spacers you need.
I have somewhere described how I DIY Spacers using mill and rotary table,
Material - calibrated brass(bronze, capton) foil, 0.01...0.1 pessed (bolted) together ca 3...5 mm stack, upper and lowest must to be some kind of stronger material, cfk, alu ... and then cut it ...
Preload torque is matter of feeling for me. At that maximum preload depends about grade of bearings. I dont use hard preload, rather somewhere middle of between smallest SLACK and HANGING (start of jam, never try full jam(hang)).

"measured thickness of the inner and outer races of the bearings ..." - at least for me it near never helped. Even bought from factory two GRW 1/2/001 ... they told me "you never need spacer between" - in fact did need and used 0.01 capton!

Please show the draft of your assembly, perhaps I can carry out some useful thoughts.

cheers,
herbert

wildwestpat
11-15-2009, 09:15 AM
Hi Mark

The fit of the bearing to the shaft will be covered in the bearing specification. Press fitting the bearing will of course expand the diameter of the inner race and this alters where the balls roll with respect to the outer race. If carried to extreem this impacts on the life of the bearing as does the amount of pre load used. Pre load also keeps the balls in contact with the race way and helps stop then skiding which leads to shortened life as the balls wear with flats on them!

To state the obvious the life is reduced with speed of rotation and the forces applied. There are a host of other factors including lubrication - cage material - type of load etc. In service life calculations are a bit gutsy and some manufacturers have simplified the calculation by providing calculators on line. If you have an evening to spare try looking at the web sites of the big world players in precision bearings and see how all these factors impact on the life that can be expected.

With high speed rotation balancing of the rotating parts and run out are probably going to limit performance life as much as the fit of the bearings. For precision work shrink fitting is common as is the use of anerobic adhesive and certainly no hitting!

Good luck as I want to see some pics of a finished spindle.

Pat

RotarySMP
11-15-2009, 11:49 AM
Hi Pat,

Thanks for the answers.

The manufacturer went TU after the German reunification (or at least got bought out). There is no info in these bearing on the web, so I can forget spec sheets.

If you have experience on similar AC bearings, would you mind giving me some ball park numbers on the thickness of the shim stock to space the outer races, and the preload torque on the inner races?

From the SKF site, the minimum load for a normal quality 7204 would be about 460N. For a P2 spindle bearing on a JS3 shaft, SKF recommends a fit in the range of +0.004mm (press) to -0.001mm (sliding), given what I have measured, and the feel of the bearing pushing it by hand about 3mm onto the shaft, I would guess that this shaft/bearing pair are quite well matched.

The fit is not going to be very tight, but will be beyond a hand fit. As best as I can measure them, the ID and Shaft are seem to be within a .0001". If pack the shaft in dry ice, and heat the bearing, I expect I could hand fit it, but that does not help my assembly problem, of not being able to then install the bearing cover screws.

wildwestpat
11-15-2009, 03:25 PM
Hi Mark

The fit on the shaft sounds good to me. Rather than press the bearings on to the shaft when the time comes it might be better to freeze the spindle using one of those aerosols used for fault finding on PCBs and also used by plumbers for working on pipes with out the chore of draining down the system by freezing the water with a very very cold spray of gass. Warming to hand heat the bearing but no hotter than hand heat or you could fry the grease, seals and cage.

The shims for pre loading are as far as I am aware specified by the manufacturer and supplied as part of the set. This helps in part to explaing the vast increase in cost associated with matched pairs. I also think the trend is to having the inner race ways sized such that with the outer races back to back the loading is determined by the faces on the inner raceways being in full contact.

Now to your problem the manufacturer has ceased and you have no data. Are you sure the bearings you have are a matched pair or are they two independent bearings that just have the same part number? If the former there is a good chance that they may not require a shim. This can be checked by making a jig consisting of two cutaway thick spacers with a bolt that goes through the spacers to make a sandwich with the bearings. The thick ends of the inner races facing the spacers and the outer rings in contact with each other i.e. the thick side of the outer rings are in contact. Tighten the bolt to barely finget tight. Check the gap between the outer bearing rings. This should be zero if they are a matched pair. Now the question is are the inner bearing rings in contact. This can be found out approximately by measuring the distance between the inner races withe micrometer anvils in the cut outs in those spacers you have made for this jig. Compare the length in the jig with that of the sum of the two race inners measures separately. There should be a gap if they are a matched pair and it should be small. Now increase the bolt up pressure and measure again BUT only bolt up to a relatively low torque and keep checking that the outer race pair which should rotate as one is free to spin. This will establish the shim needed.

This can only be regarded as a rough and ready approximation and depends on the measurements being done accurately. As you have found measuring to tenths is an art not a science with a micrometer!

I am not advocating this as a method for general use and can not stress too much tha bearings should not be removed from their protective packing till the very last moment. This also keeps matched pairs together and avoids any doubt. Bearings that are loose are unlikely to be matched pairs.

There is a category of double row agngular contact bearings that are manufacturered as a single unit. These avoid many of the problems - look at SKF 4201 ATN9 good for 20,000rpm and a nice radial and axial loading as well. (About 20 euros or less for a single which is equivalent to a pair of A/C bearings in SKF.) The series of bearings are also known as 3205 and 5205 depending on source and application details. I am using these for ball screw mounts and can say they are pre loaded and are easy to mount. Just dont make the spindle too big and dont force the outer into a bore that is too small as this also messes up the internal clearances / preloading. I am using Locktite with just finger pressures to assemble. This is also because I want to get the thigs apart and moderate heat should make the Locktite give up it grip. Or so I hope!

Hope this helps

Pat

RotarySMP
11-17-2009, 04:04 AM
Thanks for the response Pat.

The bearings I have are not a matched pair. Would you be able to upload a sketch of that jig please?

I guess to address the assembly issue of the spindle design here, I will have to put the spindle shaft between centers, polish down the bearing seat to a nice hand sliding fit, and go a little looser on on the shaft between the bearings. Then I could assemble the bearings into the housings, with the bearing cap bolted in place, and slide in the spindle afterward.

wildwestpat
11-17-2009, 05:28 PM
Hi Mark

I am on the road for the rest of the week so will not beable to do any drawing till the week end assuming I get some free time. You might review how you are going to assemble the spindle into its housing as these bearings are expensive an need care in fitting.

Regards

pat

RotarySMP
12-07-2009, 02:53 PM
Hi guys,

I have been slowly working on my low speed spindle, but it is not too cold to stand on the balcony for any length of time in the evening.

I found an early use of the method of bearing preload Herbertkabi demonstrated here. Turn out cataract (turned into Hardinge) used it on some of their early Lathes.
http://cnczone.com/forums/showthread.php?t=12184&page=11

Pat, did you get a chance to sketch up that bearing preload measuring jig?

Herbert, do you know of a source for shim stock in Europe? I speak german and work with Austrian engineers, and searched ebay for:
Abstandblech
Distanzblech
Ausgleichsblech
Merklblech
Futterblech

And keep turning up blank. I am going to need to get some thin shim for preloading my bearings.

Herbertkabi
12-07-2009, 07:12 PM
Very-very seldom you find the right size shims - I make needed shims myself.
I have tried to explane how I make it sevaral times - seems none understand my DIY English :confused:
Lets try to illustrate ...
You need to find different thickness thin sheet materials, like bronze, brass ... kapton ...nickel alloys ... Stack pieces together between two alu disks via centre with adequate bolt (screw) ...
Then using rotary table and milling machine (or just cnc mill) cut out needed size ring - will get a lot of shims with different thickness. First large shims, then smaller ...
Cheers,
Herbert

JLSD
12-08-2009, 04:23 AM
Hi Mark,
You could do worse than looking up local model engineering groups, or competitive aeromodellers. I've cut plenty of small cylinder head shims/gaskets over the years, and my material has generally been from model eng. suppliers.
If you're really stuck, PM me, and I'll see what's tucked away.
John.

RotarySMP
12-08-2009, 05:13 AM
Thanks for the offer John. I'll need to make pats fixture to measure up what thickness I actually need.

Thanks for the pictures Herbert. Have you also tried punches?

Shim stock must be available here in Europe, I just have to work out what german name is being used. I guess if I can't figure it out, I'll have to drink some canned beer :). I am guessing that aluminium drink can is too soft to make ideal shims though.

My Dad is coming out from NZ in a couple of weeks, so I got him to dig around the shed and bring out some shim stock. The thinnest he could find is 0.3mm, which I expect will be too thinck for the P2 bearings I bought.

Herbertkabi
12-08-2009, 06:11 AM
Thanks for the pictures Herbert. Have you also tried punches?

.

I hope you meant not punches like used for carton or rubber :rolleyes:
Very hard to make adequate "punches" (stamps) to stamp precission shimes from such thin sheets. It is possible, but what is costs ...:eek: ... and every size needs own stamp ... inner and outer ... and mother and father ... :cool:
cheers,
herbert

BobWarfield
12-08-2009, 11:05 AM
What ho? The spindle building game is once again afoot!

Spindles are one of the "pinnacles" of machine work. Very exacting, very interesting, and very valuable when you get a good one.

I've collected a lot of data on this over the years. Eventually I want to build a spindle cartridge for my mill that's capable of 10K rpm or so. It'll be R8 or perhaps NMTB30. My notes can be found here:

http://www.cnccookbook.com/CCMillBeltDrive.html

Meanwhile, a few thoughts:

- Avoid "pressing" bearings unless its to remove known bad bearings for replacement! NCCams always used to say it should never be done. I have seen that corroborated in a number of places. There are spindle rebuild threads on Practical Machinist, this board, and other places on the net that are worth tracking down. It is very easy to brinell the bearings at which point you just bought a new set.

- Always heat shrink the bearings onto the spindle as WildWestPat suggests. You can go hotter than hand warmth though as we'll see shortly. In fact, if you check the spindle rebuild threads, you will find precision machines that don't even require heat shrink. That may be important while you're studying preload shims.

How much preload is the eternal question unless you are fortunate in having a matched set of bearings. The answer is simpler than you would think:

As much as possible without damaging the bearing's operation and life.

But how do we know? There are two approaches I've seen that make sense to me.

First, go get the bearing catalogs and see what they recommend. Even if there is no data available for your particular bearing, use data from similar bearings. OK fine, I know the spec, but how do I "make it happen" with my bearings? On the cnccookbook link are ideas for a couple of test cells to do that. You basically need a controlled way to apply that much preload so you can measure the displacement of the races and then apply a shim equal to that displacement.

That's a lot of trouble, eh? So here is the second way, and one I like a lot better.

The usual way to get into trouble with too much preload is heat. There is a threshold where things are so tight that as you run the spindle it gets hot, things expand, that increases the preload, things get hotter, and you get the picture. Not good!

Well how hot can it be?

The patient stalker of information eventually finds a figure of 160 degrees F. This is why I say you can go hotter than hand warm when heat shrinking! Bearing shops keep a hot plate set to an appropriate temp for doing this.

For experiments, get a handy infrared thermometer. Make yourself a test jig where you can run your spindle on the bench. Crank it up to desired speed and shim the bearings until you can run as close to 160 as possible and the temp is stable. I'd let it run for an hour to be sure it's stable. If it climbs, you've got too much preload. Take it apart (remember the comment about a non-heat shrunk spindle? Here is where you are happy to have one) and reduce the shim size.

BTW, a real bearing shop wouldn't use shims. They'd put the bearings on a special jig with a surface grinder and remove some meat from the race so that it preloads when you torque it down. I've never seen detailed procedures for this, but if you have a surface grinder it could be figured out once you have the desired shim specs.

Phew. Suddenly this seems like a lot of experimentation and work!

Sorry, there is a reason precision spindles are so darned expensive. But, if you like to experiment, it is fun work at least, eh?

BTW, Herbert, love your spacer cutting jig. That's going on my spindle page!

For those that don't want to fool with it, McMaster Carr sells bearing shims too.

Mark, looking forward to seeing your new spindle underway!

Cheers,

BW

wildwestpat
12-08-2009, 05:54 PM
Hi Mark

Unfortunately due to the rush in the office I am not going to be near a drawing program on which to make a sketch. I will try and post a hand drawn one some time tomorrow between customer visits if the scanner will play ball! The weekends are a domestic no no in the run upto Christmas so no luck then either.

I am a little concerned about the use of shims as the AC bearings are very ridgid which is after all why they are good for spindles. This means that they will take a very large trust load with little axial movement. Put another way the sensitivity to shiming as a method of pre loading will be very, very sensitive. I have used fine screw threads to run a machined collar and nut down on the race to pre load it. (The pre load being applied by the center raceways with the outers force fit in the housing.) Adjusting the pre load by feel. Tighten until the drag can be felt and lock in place with just perceptible drag chech and adjust until this is achieved. I think shiming will be difficult if not an impossible way of getting the required pre load.

I am also concerned that the bearings should be a tight fit in substantial housings if the best is going to be got out of precision bearings. The force fitting does not of course imply that the balls are under threat as the inner is pressed on separately from the outer. It looks as if the need to have the pre load sensitivity is getting mixed up with the simple expedient of having an adjustable preload via a thread on the inner part of the spindle where a slop fit is required to make the adjustment.

If you are interested look at the fitting instructions for angular contact bearings and also at the fit tolerances on the shaft and housing. This information is for manufacturers of high speed spindles and is not applicable to DIY. The fits specified will require assistance in fitting the bearings either by thermal expansion or use of a press with suitable jigs. Angular contact bearings are easy to fit with a press but can not usually be removed without wrecking the bearings. This is why high speed spindles require specialist services both in terms of technician trainning and in the sophisticated equipment required and explains why there are specialist facilities that offer to service these types of assembly fitting new bearings as a matter of course. To make many of the assemblies practical where there are multiple banks of bearings flush ground matched sets are specified. i.e. clamp them up tight and the pre load will be perfect! All this is not DIY! I have been using the 320X\520X series of double row angular contact bearings with some success on lead screws but have not tried them in a spindle as I am satisfied with good quality tapper roller bearings.

Hope this helps.

Regards

Pat

Herbertkabi
12-08-2009, 07:31 PM
hi Pat,
You read a lot - respect - but never tried?
Readings are primary before to do something, of course, but then next step is to try. Fitting of bearings, like many things in relation to Spindle, is question about experience and intellect, ... and also good fortune ... at least my high speed spindles, these ones where I have used super precision angular contact bearings works very well. Some of theses have been used long enough time, so I can say - are long life tools. To be precise about &#180;intellect&#180; I meant - just do not foolishnesses :rolleyes:
Anyway - viva DIY :cheers:
Regards,
Herbert

wildwestpat
12-09-2009, 06:59 AM
Hi Herbert

I think you have put it in a nut shell. In all things there is no substitute for hands on experience certainly bearing fitting being no exception. The current trend is away from the very tight force fits of yesterday to the use of aerobic locking fluids to reinforce with what can best be described as a light force fit.

I have spent some thirty years in satellite and radar research and this has given me a very wide range of experience in both mechanical mechanisms and electronics. During this work I have had the pleasure of working with some of the best fitters and toolmakers in an integrated team. It is no good dreaming up theoretical parts if they can not be made! In this sort of environment where the team costs are very high it is necessary to defend all all design descisions with solid information. This is why I always like to have the manufacturer's data sheets and particularly the application notes as these make a good springboard for a different application.

The world wide web has made access to data sheets so easy but it has also unleashed a lot of opinion based stuff from armchair practitioners who have never made anything or just assemble kits of prepared bits!

You have guessed my guilty secret is insomnia! Hacking metal is not very popular when everyone else is asleep so reading is about the only option.

Your work on high speed spindles fascinates me. In particular how are you balancing the spindle - chuck - drive coupling etc?

Keep up the good work

Regards

Pat

Herbertkabi
12-09-2009, 07:57 AM
hi Pat,
I have acquired and took apart seven high speed spindles made by well-known companies - never met problems with removing/inserting of bearings - was easy with help of common means you can find even in most of garages. Yes, good sense is the most of you need for - two first spindles was not possible to assemble again because did not make correct notices and drafts about line up, but next ones was assembled after repairings successfully and sold away (understandably I bought defective spindles).
Presently Im busy with two plane soft bearing dynamic balancing machine ...
also categorized as "no way to DIY" ... but in reality factualness speaks quite the contrary. Found few new friends and with some helps I have progress about. When done then ca $15k saved. OK, I can also buy but why ... at that I like such kind of challenges, I like DIY.
Best regards,
Herbert

PS:
In some points you are correct - military stuff - you never can remove bearings without damages ... as well as another kind of tech. like even common hard drives ...

wildwestpat
12-09-2009, 08:56 AM
Hi Mark

I have sketched out the jury rig for measuring the clearance, if any, between the inner raceways of non matched pairs of anular contact bearings. However on reflection I do not think the pre-load can be determined by measuring the gap between the raceways of uninstalled bearings to sufficient accuracy. The problem is that angular contact bearings are designed to be ridgid and resist both axial and radial movement. This means that there will only be a minute movement from just touching to full load. With such a small range of movement between full load and no load, with the balls making contact with the raceways at all times, I have changed my mind. I now think it is necessary to adjusting the bearing pressure as part of the final install process and not as a predetermined pressure applied by shims. In any case the spindle should be run in for a few hours and the pre-load rechecked and adjusted as necessary.

For the above reason I am withdrawing any remarks I made about measuring the gap as I do not think this will work as it is the as installed pressure that has to be adjusted.

Kind regards - sorry about changing my mind.

Regards

Pat

wildwestpat
12-09-2009, 09:54 AM
Hi Herbert

Looks as if you have a health desire to do it cheaper and better than any stuff that is available. In my book this is what 'engineering' all about. In many cases the break throughs are achieved by gifted amatures and it looks as if you are one of them.

I do not know where the term DIY has been used to imply limited skill. In my book it means with limited resources in the way of tools and equipment. The active mind is of more importance than all the test equipment and fancy machining gear in the world is in the possesion of people with no imagination or hunger for a better way of doing things.

It is just that when I hear of people running the risk of abusing bearings to the point that they have dented (brinelled) the bearing surfaces I think 'do these people have any appreciation for what they are doing'. It is very obvious that most of the pepole contributing to this thread are not going to do that. But there is a hidden risk with high precision bearings where the determination of pre-load by measurements that are taken prior to the bearing being mounted and the risk that the pre-load calculated will increase too much when the spindle is assembled. This is most likely to show as tram ways and flats on the balls after a short period of running rather than the typical dents caused by subjecting the race ways to a crude brinell impact test. The excessive pre-load would also show as excessive heating as well as nasty noise.

The objectives of military and similar designers is for absolute reliability and removal of all adjustments can be a serious objective on many of these projects. Again it is horses for courses.

Wishing you the best of luck in achieving a means of achieving dynamic balance.

Kind regards

Pat

RotarySMP
12-09-2009, 10:16 AM
I really appreciate the discussions here.

No worries Pat, I am not a lawyer, and I am not going to sue you unknown east german P2 bearing on a Chinese ER-16 collet spindle craps out :)

Since I bought these bearings off Ebay, and the manufacturer is gone, no data is available. To be honest, If I had all the data and knew exactly what I my target preload is, I doubt I would hit that target first time, seeing as I am working with a CNC'ed 7x12 chinese mini mill, out on the balcony in the middle of winter. I am using a lot of time (http://www.5bears.com/cnc16.htm method ) to get tight sliding fits, so that I can assemble by hand without pressing parts together. If I get something to work nicely, I could then look at using a bearing locking fluid (Calling it glue is not engineering cool, right :).

Maybe a reliable, high speed spindle is not possible given my tooling, environment and machining experience, but it is fun to try. I bet if I make this spindle and run it till it fails I'll be in a better knowledge position when it comes time to make the next one, and a better all round machinist.

I do have decent measuring tools, (once my father brings out some decent Mitutoyo telescoping guages at christmas, so I should be better able to precisely measure bores cause my current ones are a definate weak point in my tooling).

Yesterday I half assembled my low speed ER-32 spindle and it became clearer what you were talking about in terms of a bearing play measuring jig. I still think using your method is valid as a first step to get a feel for what range of shims will be needed.

Bob made a good post above about using temp rise to confirm preload.

I am guessing that the preload range for these precision AC bearing is going to be less than a thou (0.025mm) from too loose to too tight, as Pat points out. What do you guys use for such accurate shims? McMC seems to only have shims starting as 0.001" (and only for some sizes, for 20mm ID I think the thinnest are 0.003". Beer can is about 0.004" (and I don't like using aluminium in machine parts).

Herbert, did you end up using the thin Aluminium foil from your sandwiches to fine tune the preload? What thicknesses did you end up using on your AC bearing pairs on your last couple of spindles?

Looks like I'll order a bunch of shim packs form McMaster Carr and get a friend to bring them over when they do an aircraft delivery.

BobWarfield
12-09-2009, 10:30 AM
I do have decent measuring tools, (once my father brings out some decent Mitutoyo telescoping guages at christmas, so I should be better able to precisely measure bores cause my current ones are a definate weak point in my tooling).

...

I am guessing that the preload range for these precision AC bearing is going to be less than a thou (0.025mm) from too loose to too tight, as Pat points out. What do you guys use for such accurate shims? McMC seems to only have shims starting as 0.001" (and only for some sizes, for 20mm ID I think the thinnest are 0.003". Beer can is about 0.004" (and I don't like using aluminium in machine parts).

Herbert, did you end up using the thin Aluminium foil from your sandwiches to fine tune the preload? What thicknesses did you end up using on your AC bearing pairs on your last couple of spindles?

Looks like I'll order a bunch of shim packs form McMaster Carr and get a friend to bring them over when they do an aircraft delivery.

Some thoughts:

You might want to consider a line boring setup for machining bearing pockets on your lathe if the pockets are at all large relative to the lathe's capacity. Such an arrangement will be more rigid.

RE measuring these bores, I think telescoping gages are going to be tough. It's really hard to achieve the degree of accuracy necessary with them, and they're very subject to technique. A dial bore gage would be preferred but expensive. I haunted eBay for a long time before I got a reasonable deal on my Mitutoyo bore gages.

But there is an easy and accurate solution. Make yourself up some go/no go plug gages. You can measure their OD's with a micrometer. I've used this approach a number of times before I got the bore gages and it works very well.

On the shim stock, you're just going to have to run some experiments to see what is needed. It won't be a lot, but I don't know that it's way less than 0.001 either. If it was me, I'd use shim stock and Herbert's method of machining that into shims.

RE the whole DIY question, machinist's are DIY by definition. A machinist should be able to build whatever they desire with the tools at hand. There are no end of examples of talented machinist's accomplishing wonders ranging from POWs in Japanese camps building machine lathes from nothing (great story from Lautard's books) to the many examples on these boards. It is poor marketing that leaves the DIY moniker in short shrift.

People who build airplanes in garages don't call them DIY or homemade, they call them experimental aircraft. Better marketing!

I would suggest the equivalent here is that your spindle is "shopmade" as you've demonstrated you are a machinist.

Cheers,

BW

JLSD
12-09-2009, 10:56 AM
Hi Mark,
I've been head-scratching over this, and attached are a couple pics that may help. One is my trusty setup for shims, just an acetal pad in the chuck and an opposing pad exactly I/D to clamp from tailstock. Tool is just a hand ground inverted HSS knife edge. (Could've made 20 shims while I was typing this!!)
The other would give a basic method of assessing preload from the drag between the unclamped raceways. Not perfect, but at least you'd know whether you had any! Given a pair of bearings with known preload would set some kind of start point.
As to the general principle of spacing raceways, I'm not too confident about the idea of super-thin shims, and one of my baby spindles will be a real cheapo with only two bearings, but inner and outer races clamped, using different length spacers, e.g. 30.00/30.01.
The spindle arrangement will allow setting the loading of the core assy BEFORE committing to the housing, using similar torque arrangement to sketch.
John

Herbertkabi
12-09-2009, 11:48 AM
I really appreciate the discussions here.

Herbert, did you end up using the thin Aluminium foil from your sandwiches to fine tune the preload? What thicknesses did you end up using on your AC bearing pairs on your last couple of spindles?

Looks like I'll order a bunch of shim packs form McMaster Carr and get a friend to bring them over when they do an aircraft delivery.

Last spindles used perfect matched pairs - no needs for any "tunings" between. Earlier I used different materials, the thinnest was 0.1 mm special rolled brass(bronze) and 0.05 mm nickel alloy, dont remember exact name
anymore.
But anyway I need and use thin shims - not between pairs but in several another places where precision trim wil be needed, like back side bearing cup ... and between face flange ...
cheers,
herbert

RotarySMP
12-09-2009, 11:59 AM
Throw out a few questions and then follow up the answers with clarifying questions, and this forum is a great place to learn. Thanks guys.

Line boring... I'd need to make a between centers boring bar, then I need to make a micrometer tool setting jig to accurately set the tool bit in the boring bar for each pass. Then I need to make a spindle housing holding jig to mount it to my cross slide during boring.

It is a daunting prospect. I have thought about making the between centers boring bar and setting jig before (I really want to make a decent rigid tailstock for my lathe one day), and will make one sooner or later, but right now I think I'll be putting my time into finishing the mill (getting it CNC'd), finishing the low speed ER-32 spindle, and finishing the bending brake.

I like how Herbert mounts the upper floating bearing in a housing located by an o-ring, allowing a little misalignment there. Sure it makes the entire system softer and less rigid, but the actual cutting forces must be minuscule on a 30K+rpm high speed spindle driving <6mm end mills. Herbert is reporting good experience with his, so I will be copying this design for the first one.

John, I like your method or cutting the shim. Using the tail stock to sandwich the shim must be a real time saver.

How do you cut the ID?

If I understand your preload jig, you torque up the bolt holding the inner races of two bearings together, while moving the outer races with the clamping levers. Once the lever slips, you have your preload setting. Have you any torque measurement to give guidance on what that slippage torque should be? As drawn, your slippage torque could be totally different from mine, if we maching those bore a fraction differently.

Pat, you talk about setting preload using a preloading nut on a thread. I had always read that this is bad practice, as it is difficult to the real preload being applied, verses the torque absorbed by the threads. I do understand your point that this lets you directly "feel" the preload.

JLSD
12-09-2009, 12:23 PM
Hi Mark,
Should've said, the clamping pad is exact I/D, allowing a "touch-off" reference for I/D, but O/D CUT FIRST. I've used this for soft metals up to approx .25m.m., and plastics to .8m.m., (this with 35m.m. radial width in the breeze!)
Smallest I've needed were 7X10 for model I/C crank bearings-lost more in the chip tray than used!!
John

isvflorin
12-09-2009, 04:18 PM
Ok guys, I'm in the spindle game too, been trying to put together a DIY spindle.
My question is : paired angular contact bearings, laser etched - do they need any spacer for preload ? I bought them from ebay and they even came with a datasheet but unfortunately it is written in Chinese. I wish I could read chinese...

regards,

Florin

Herbertkabi
12-09-2009, 06:25 PM
Mark,
Misalignment? Please precise where I have. About what draw you are speaking?
My spindles are as rigid as possible ...with used shank diameter.
Some parts I have made new and new ... turned/grinded 2...3 times until got exact fit - no slacks, no jams. Do you mean this spindle (attached)???
There the only two O-rings are for sealing motor cooling and works as well like motor vibration dampers, +motor bottom seal.
Where "floating bearing" there are not drawed (not shown) set-up screws - three axial screws are for preload - through FIXATOR to "saucer" (no named) to inner ring of bearing ... three radial screws fix FIXATOR (one piece with coupling mother side) to the groove on the shank.
Regards,
Herbert

Herbertkabi
12-09-2009, 06:57 PM
Ok guys, I'm in the spindle game too, been trying to put together a DIY spindle.
My question is : paired angular contact bearings, laser etched - do they need any spacer for preload ? I bought them from ebay and they even came with a datasheet but unfortunately it is written in Chinese. I wish I could read chinese...

regards,

Florin

Some are just "matched pairs" , real ones are really matched pairs of super precision AC bearings - there you do not need any additional shims or spacers. Real matched pair of SPAC&#180;s costs a lot ... but somertimes ... if you are happy ...
What we can do when bought "matched pairs"? Like with common pairs of AC bearings and even with two not-paired SPAC bearings - you just need to try and measure and find out exact thicknes you need. This is not a simple work!
Sometimes you can use two precision grinded(!!!) steel shims (spacers) - for example outer 1.00mm and inner 0.95mm ... (depends about type).
Please understand - it was *for example*.

regards,
herbert

wildwestpat
12-09-2009, 11:42 PM
Hi Mark

Using a thread to adjust the pre-load works and works well provided you use a very fine thread. Yes the adjustment is a bit hit and miss. I have always had a good listen to the bearings using a contact microphone during set up with the shaft rotated at moderate speeds and again during the first hour at full speed. You hear the bearings making a delightfull singing noise when they are happy and a very sorry noise when not loaded. The noise when they are over loaded is even worse! I guess it would be informative to use a scope to look at the wave form from the contact microphone but the noises are so distinctive headphones are good enough.

Some thirty years ago shim material was available in laminated form. Many layers of thin material - alli alloy of some sort - was lightly glued together. This was I think called Rose or Rose's metal. Washers were turned out of this laminated sheet and peeled off as needed. May be some one knows of the existence of this material and where it can be obtained. In the electronics industry use is made of thin heat resistant plastic to insulate transistors for their heat sinks. This plastic film is very thin and robust and resists puncturing well which could indicate that it is stable under pressure.

The use of plug gauges is a good tip and as well as the conventional 'go' - 'no go' it is helpful to make the lead in the form of a slight taper for the first few mm. This gives an early warning as the exact size is approached! Many machinists use the same approach in reverse to check the final approach to size by making a trial run on the start of the bore. I hesitate to mention this as so very basic but it can save a lot of tears but can be overlooked in the excitement of getting a good surface finish.

Regards

Pat

RotarySMP
12-10-2009, 07:44 AM
Herbert,

I think I made an wrong assumption based on the grooves you turned in the upper bearing carrier (Steel dish) (see picture).

I thought you machined the main spindle housing bearing OD's in two set ups, and then used O rings in those grooves to provide for posible slight missalignment. I see from your CAD model that my assumption was incorrect, sorry about my error.


Which method did you use for machining the main housing?

1/Bore the OD for the lower AC bearing pair, then remove the housing from the lathe, turn it around, remount it, indicate it in and bore the OD for the steel dish which holds the upper bearing?

or

2/ Mount a boring tool between centers, mount the spindle on the carriage, and bore out both lower AC bearing pair OD, and upper bearing carrier (Steel dish) OD in a single setup?

RotarySMP
12-10-2009, 07:49 AM
Hi Pat,

Peelable shim is still available from McMaster Carr. I have only ever used it on one job, shimming the side play while reinstalling a Short skyvan nose landing gear, which had been packed in dry ice. Needless to say, peelable shim does not bring up fond memories.

McMMC is also 0.001" per shim layer.

Thanks for you input on using a microphone ot check on the bearings.

Herbertkabi
12-10-2009, 09:16 AM
Yeah, these grooves are for keeping grease.
Housing I drill full lenght (with 24mm) and turn on the lathe, Outer to final size and ONE side of inner, very carefully and up to 0.00 , then I cut off exact lenght +0.5...1.0 mm.
Take out all from lathe.
Then I do turn (from thick-wall alu tube I have) every time a new special precision holder into this exact fit ID. I do (slightly) press this housing - so I can turn ANOTHER side of ID of housing without any errors - and again size exact 0.00. For final ID +0.01 or more I later using simple honing tools. I use only the best cutting/boring tools in the lathe (At least what I think what are the best for me ... Im not any expert or nonpareil machinist - Im autididact and I do all like I think it is the best).
These thick wall aluminium tubes I spending - Im happy - because all these 200mm pieces will be used for my another works I need to do for bred ;-).
The final is honing - I do use the same alu tube (still in Lathe) and ... honing up till bearings fit from one side and sliding cup fits from another side. Then promptly I examine exact fit of upper bearing ("floating") inside this sliding cup.
Oh dear ... my English ...
cheers,
herbert

Herbertkabi
12-10-2009, 10:05 AM
Some more illustrations, my acad does not want to work well anymore, not updated, no upgrades ... I dont want to buy a new license. Two tears ago bought SolidEdge - excellent!!! but unfortunately old man with salt and pepper beard cant never learn to use it. But OK, may be I will ...
One picture is the same but air cooled. And one is ATC, I have made three different ATC-s ... thats because now Im busy with dynamic balancer - when integrated motor (in the same shaft) then no way without own balancer.
regards,
herbert

RotarySMP
12-10-2009, 10:29 AM
Thanks Herbert. Do you have any photos of using those thick wall aluminium tubes please? I am having trouble picturing how you do this.

Herbertkabi
12-10-2009, 02:53 PM
Thanks Herbert. Do you have any photos of using those thick wall aluminium tubes please? I am having trouble picturing how you do this.

No,
And I have no time right no to go to workshop, to cut, to install in to lathe and make pictures ... sorry,
What is there incomprehensible? It is most primitive way to keep all in centre because Lathe Chucks lies always ... and changing 3jaw chuck to 4jaw one and then set-up and playing with indicators ... not for me - I do make this "artificial center" - exact perfect inner center- like collet ... - I do this mach more faster and more precise than Im able with 4haw chuck.
Of course it is simple for me because I have a lot of this L-200, OD-82, ID-40 alu,
And also very understandable is - if you need with starting to find any of this kind materials - then for you this is not a brilliant idea at all.
Cheers,
Herbert

isvflorin
12-11-2009, 01:10 PM
ok here it is: I got the parts finally,
NSK 7003ATYP5 bearings (can't find any info on them, don't know if you can tell from the picture but they are laser etched in a pair) they are only P5 precision so I guess they won't hold too much high speed.

Got my UBEC, controller and servo tester, but never used this stuff before, I have no ideea how to wire them, they don't have any precise wiring diagrams.
I'm not sure if the controller has BEC incorporated or not, can't figure it out. Power supply is 23-27V, only 20Amps. Motor is 1200kv.

I have straight shank collet holder and a housing made for the bearings, but still need to remachine it on a lathe, also make a few more parts.

Does anybody have a good link for how to wire up UBEC- servotester-controller-motor ? Anybody reads chinese ? The bearing datasheet specifies some spacer dimensions I guess.
Herbert do you have any close-up picture of a servo tester-ubec-controller-motor setup ? I never wired these things ever, don't want to fry anything.
Also do I need a programming card ? Or I can run these without it ?

Florin

Herbertkabi
12-11-2009, 03:05 PM
Its simple. But you need power supply instead of batteries. What Voltage? *** Motor kV x Voltage = RPM *** Dont use too hight voltage! You dont need more than maximum 30.000 rpm for beginning. Even less.

3-wire connector from ESC goes to Servo tester where written Servo (black->ground)
UBEC connected with ESC +/- power ends - Connector to Servo Tester (see -/+)
Potensiometer - always start from endmost CCW!
Now when power in then ESC makes hes signals ... then carefully turn potensiometer ...
When not right direction, then just change two (of three) wires (motor wires) between (when POWER OUT, OF COURSE).
It will work with factory settings, you can try short time, but surely better if you&#180;ll make clear for yourself all SETTINGS! Do you have instruction mamual?
You need:

Timing Mode Setting -> 1&#186; - For 2-4 Pole Inrunner Motors !!

Pulse Width Modulation(PWM) Setting -> two choices 8 and 16khz (any - later look what is better for you)

Cell Type and Number of Cells -> choice any (dont think about NiCad ir Lipo) just Volage ... cut off is for when airplane batteries will come empthy ...)
6-lipo or 18 Nicd = ca 24v - thats all.

Throttle Setting -> Soft Acc !!!!!!!

Brake Setting -> No Brake !!!!!!!

Direction and Cutoff Type -> any (you can change direction as I spoke before ...)

Try to find some friends who acts with brushless RC stuff ... or read/ask from
http://www.rcgroups.com/forums/showthread.php?t=657606&page=4
http://www.daddyhobby.com/forum/showthread.php?t=49280
http://www.wattflyer.com/forums/showthread.php?t=11604

Cheers,
Herbert


Yeah, now I see - 23-27V, only 20Amps. Motor is 1200kv. ...
20A is enough. and your max RPM will come ca 30.000. If you can regulate this Voltage then choice 23 (minimum) - 27.600 RPM is OK - because you are not sure about bearings.

wam
12-16-2009, 09:17 AM
Ok guys, I'm in the spindle game too, been trying to put together a DIY spindle.
My question is : paired angular contact bearings, laser etched - do they need any spacer for preload ? I bought them from ebay and they even came with a datasheet but unfortunately it is written in Chinese. I wish I could read chinese...

regards,

Florin

Which dialect of Chinese?

isvflorin
12-16-2009, 10:02 AM
Hi there,
I have no ideea about the dialect, might be even Japanese, it's all Chinese to me (pun intended). Here is the datasheet. There are 3 bearings all laser etched in arrow shape, 2 of them are paired and the 3rd seems to be the 4th bearing from another pair (like they initially were 4 bearings all laser etched in matching pairs from start to end bearing - from this configuration of 4 bearings I have numbers 1,2 and 4, judging by the etching on the side)

BobWarfield
12-16-2009, 10:48 AM
The laser etchings are orientation marks that tell you which face goes which way and how to rotate them in their pocket to minimize the runout. NSK's will be documented on their web site. At the very least, go check out how to line up the marks.

I suspect you will be able to tell from the site whether you need a spacer, but I'll bet not.

Also, those are inspection sheets. The diagram is telling you pretty clearly how it wants to sit for proper preload. Note the offsets in microns. Take the bearing code, 7008ATYP5, and go look it up on the NSK site.

Best,

BW

isvflorin
12-16-2009, 10:55 AM
Bob,
NSK website was the first thing I checked of course. However these apear to be really old stock bearings and they changed numbering since. The new numbering is different and can't see any corelations between.
They are probably old style numbering, who knows from how many years ago.
I'll keep looking, however the datasheet gives some micron numbers that appear to be tolerances and dimensions of inner and outer race.

I would be really nice not to need spacers, I guess there is a simple test I can make, just assemble without spacer and see if there is axial play ?

FLorin

BobWarfield
12-16-2009, 11:10 AM
Take a closer look at the diagram on the lower left. Those dimensions are displacements from the resting state of the bearing. Looks like preload to me.

Worst case is you need a spacer the thickness they're calling out. And yes, your penalty for having gotten them cheap is you will need to painfully wade through their online site to figure out their numbering. If you just did a search, forget it. There are multiple bearing catalogs. Go find every one of them that deals with angular contact bearings, print them out, and scan through them by hand. It's a lot of work, but you'll learn quite a lot about bearings doing so.

Your second penalty is you're going to have to do some experimentation. That's ok too. Wait until you see the page in the bearing catalog that tells you what the tolerances for mounting the bearing are supposed to be. It will take you a trial or two at the lathe to hit anything close to those tolerances unless I miss my guess!

Cheers,

BW

ee_t
12-16-2009, 08:30 PM
Hi there,
I have no ideea about the dialect, might be even Japanese, it's all Chinese to me (pun intended). Here is the datasheet. There are 3 bearings all laser etched in arrow shape, 2 of them are paired and the 3rd seems to be the 4th bearing from another pair (like they initially were 4 bearings all laser etched in matching pairs from start to end bearing - from this configuration of 4 bearings I have numbers 1,2 and 4, judging by the etching on the side)
NSK being a japanese company should give you some clue to the language of the document.

Here is a google translation of the columns:

Difference method 受外 泽寸 pongee
Difference in bearing 泽寸 Law
Outer ring radial runout
Outer ring axial runout
Inner ring radial runout.
綸 axial runout in
Inner horizontal deflection

① front gap width
② width of the rear differential

2nd page:

Handling Precautions

1. The large bearings grease seal, please use as they are.

Large sealed bearings are not lubricated Gu Su Su 1, which is also fine to use it in situ, grease rust before Me-hee coarse vertical (or oil) and iron powder not 混大 to eliminate waste O 觔 Meshimasu to be washed with white 淸浄 kerosene.

2) to bring harmful results caused the wound shock and stroke in the orbital plane of the bearing during assembly, please be careful, especially dealing.

3) sign indicates radial runout of poetry place 般大 way or chamfer the inside and outside the ring E (or O) 埸合 殳 mount on the shaft axis in the visible, this E (or 0), wet place Me the. resultant plants together and place your going to be the opposite position 镢 up correctly and eccentricity of the axis: ^ Please. The outer 叫絵 places including the eccentric position of the box 较大 铀受! Sign of the outer ring and E (or 0) As mentioned I made the mounting position of the opposition will correctly position the whistle.

isvflorin
12-17-2009, 04:02 AM
Many thanks,
I'll keep working on the Frankenspindle and let you know how it turns out.

Florin

Big-tex
11-12-2010, 09:05 PM
Herbertkabi

Very nice work, I must admit I can only wish to accomplish some what you have done.

I have questions for you,
I would like to build ATC that attaches to electric motor (with brushes) with build in variable speed working up to 20.000 rpm. This is for router application.
I have seen cartrige that usovo sells but it is wrong size. I have no clue how they have them constructed to release drawbar when 6-8 bar of pressure is applied. Do you have any drawings or designs.

BTW Wy gavaritie po ruski?

Herbertkabi
11-13-2010, 05:03 AM
Herbertkabi

Very nice work, I must admit I can only wish to accomplish some what you have done.

I have questions for you,
I would like to build ATC that attaches to electric motor (with brushes) with build in variable speed working up to 20.000 rpm. This is for router application.
I have seen cartrige that usovo sells but it is wrong size. I have no clue how they have them constructed to release drawbar when 6-8 bar of pressure is applied. Do you have any drawings or designs.

BTW Wy gavaritie po ruski?

"Po ruski" is not mu mother tongue but I do it well, can read and speak easy, writing comes with lot of typos.
My own ATC ... its so-so, Im not very pleased with result, mostly because Im weak with to use and install different programs ...:(
but there all are on the one(!) hollow shaft ( 1-Model.jpg ).
This actual spindle changes 1/8" bits only.

I have bought two Usovo ATC, one just for Sherline, another was full ATC water cooled spindle WZW105 I bought without motor inside, motor I built and installed myself. Also Tool Magazin SK15 with dust cover, more sk15 toolholders and control box ... Usovo ... this guy does not want to speak with you very much, was very hard to get adequate answer to asked questions ... just wiggled out of, most of newer replied.
There are two bearings on the bottom, back/back, no more supports!, are angular contact bearings but not super precision, described max speed by Usovo exceeds factory described max speed of bearings somewhere 5krpm ...
There are piston and common spiral spring (missed in the photo) inside ... interesting solution, yes, but rigidity ... Im very-very sceptic!
Usovo SK15 toolholder fits exact in to ER16 - angle 8 degrees. So, if you buy Usovo SK15 toolholders, you can build your own ATC spindle using some hollow ER16 collet holder, just little bid thinkings, turnings, borings ...
Also Usovo drawbar can be made longer and easily used ... I have tried and this is OK.
Added photo about ATC for Sherline,
About Usovo full ATC Spindle ... Im not sure is it good idea to show detailed photos how it is made:rolleyes:
cheers,
herbert

Big-tex
11-13-2010, 11:01 AM
Thank you Herbert

I am kind of interested in design that they have and translate it to different size
tool holder that can hold collets with 1/2" shank tools for example ER20 BT30 or ER20 BT40. I like to use industry standard tool holders.

Usovo does not offer that. I do understand design is simple and it works!
Mechanical portion of it. Programming and controlling I will do in mach using control board I have. I am not looking to mass produce it.

I also speak russian I can not read and write any more it has been way to many years. I have learned the language during communist years in late 70's visiting Tibilisi running around and playing with kids.

Your help is greatly appreciated.

wam
02-17-2011, 09:44 AM
Here is an alternative for a motor to drive the spindle.

Green Tube Video - Green BD - (http://greenbd.info/video/NDitrn0J2rA/BLDC-motor-from-old-Audi-Turbo-Alternator.html)

Riceburner98
02-18-2011, 07:20 AM
So, I guess there's no way to block people from posting spam.. (@ press guy from India)

Cool video of the alter-motor there.. :)

shadowvoice
02-20-2011, 09:23 AM
I have bought two Usovo ATC, one just for Sherline, another was full ATC water cooled spindle WZW105 I bought without motor inside, motor I built and installed myself. Also Tool Magazin SK15 with dust cover, more sk15 toolholders and control box ... Usovo ... this guy does not want to speak with you very much, was very hard to get adequate answer to asked questions ... just wiggled out of, most of newer replied.
There are two bearings on the bottom, back/back, no more supports!, are angular contact bearings but not super precision, described max speed by Usovo exceeds factory described max speed of bearings somewhere 5krpm ...
There are piston and common spiral spring (missed in the photo) inside ... interesting solution, yes, but rigidity ... Im very-very sceptic!


Well... I also bought ATC head for Kress from Usovo (first version). And must to admit that most of mentioned above is true.

First and foremost I'm totally unhappy with communication with that guy. Everything goes OK until You pay a bill. Since that moment Your fortune is is in Your hands...

ATC head on it's own looks to be an idea worth to work out, but for now - it still looks for me to be a very raw project.
BTW - everytning mentioned re bearings it true. And even worse - thease bearings build up heat heavily ;-)

Much worse it goes with air control unit STG01m which is badly overpriced and... "interestingly" designed. I'd say it's a crap. I had to replace all pneumatic components to get it working more or less reliable.

Summary in short words - I spent a hell of time and efforts trying to get it working in reliable manier, but - ok, now it's collecting dust on the shelve.:nono:

marq_torque
05-28-2013, 03:27 AM
Hey friend,

I am fan of your spindle, loved it. i am also planing to make one for micro drilling work, I have lots of questions to ask you. first very quick for my decision is I found some motors Rated for 400KV ... 500KV. So storming question in my mind is, how slow you are able to run this spindle with adequate Torque ?? i am looking for something that can take load of Ø4MM Drilling in Stainless Steel. around 1000RPM !! :idea:

Regards,
AT



hi Mark,
Yes, I know DKF (GDR), have bought few sets from `Tusnelda44` for another projects,
Outer ring of your bearing has full shoulders, inner
ring has one shoulder cut away ... see the photp ... do you know the angle?
I have never used this type of angular bearings for high speed milling Spindle.
Perhaps good, but I prefer AC bearings where inner ring has full shoulders.

I use small fly cutter as well - selfmade - Radius 10mm, 7mm shank, 7075,
ca 20k rpm, even up to 30k, makes perfect surface.
Actually VCGT 130304FN-ALU inserts and have more similar fly-cutter for different inserts.

cheers,
herbert

sehdevyogesh
05-28-2013, 04:04 AM
Hey friend,

I am fan of your spindle, loved it. i am also planing to make one for micro drilling work, I have lots of questions to ask you. first very quick for my decision is I found some motors Rated for 400KV ... 500KV. So storming question in my mind is, how slow you are able to run this spindle with adequate Torque ?? i am looking for something that can take load of Ø4MM Drilling in Stainless Steel. around 1000RPM !! :idea:

Regards,
AT

Hello,
We are manufacturer of custom made Spindles from India.Our website is Spindle - Machine Spindle, High Speed Spindle and Grinding Spindle (http://www.spindlesindia.com)
Most of the time, you can reduce the RPM by 30%, for example if the High Frequency Spindle motor is designed to Run at 10000 RPM, you can utilize its optimum power up to 7000 RPM and then the Power will start reduce proportionately to RPM. But the most important is what exactly the design of the High Frequency motor is? Which can be designed at constant power from RPM X to Y

marq_torque
06-04-2013, 05:08 AM
Thank you for your input Yogesh,

But I already have used those Capital spindles, i m not satisfied with the Products after paying higher price than Better Spindles in market. Already lost Few customer relationships because of spindles from this company. also ruined my company reputation. now we are not in that Trial and error Business.

Thanks Again


Hello,
We are manufacturer of custom made Spindles from India.Our website is Spindle - Machine Spindle, High Speed Spindle and Grinding Spindle (http://www.spindlesindia.com)
Most of the time, you can reduce the RPM by 30%, for example if the High Frequency Spindle motor is designed to Run at 10000 RPM, you can utilize its optimum power up to 7000 RPM and then the Power will start reduce proportionately to RPM. But the most important is what exactly the design of the High Frequency motor is? Which can be designed at constant power from RPM X to Y

Azalin
07-11-2014, 09:44 AM
Did any one consider about using tapered roller bearings? They seem good for the job.

Azalin
07-24-2014, 05:46 AM
Hi Herbert,

I'm having a hard time finding this coupling. Is there an online source that sells such item?