Well, I just managed to smoke my Spindle controller board, a Puma SM. I was trying to add CNC4PC's C6 speed interface card, and missed the bit about using an isolated power supply. The C6 is dead, only putting out a constant 4.48 volts, and the Puma is no better, unresponsive to my old relay board, with the reset LED constantly lit.

I guess I'm in the market for another speed controller, any suggestions? Spindle monitoring and rigid tapping would be great, I'm not against the idea of switching out the 110VDC motor I'm using now, brushless would be nice, as would more horsepower.

Been there:)
Surplus Center no longer carries the replacement board (http://www.hossmachine.info/projects_3.html#circuit%20board)I used but have another (http://www.surpluscenter.com/item.asp?UID=2009013120443286&item=11-2269&catname=electric).
KB Electronic (http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2669) makes one too.

Interesting...well, at least I know cheap replacements are available.

I wonder if anyone has used one of the 2000-4000watt brushless RC aircraft motors yet. :D
If I could find a way to control it, I'd do it. The idea of low-speed torque AND 10k spindle speeds is hard to ignore...but I'm spoiled by the Haas 10k spindle.

the rc aircraft motors are controlled by a small module that requires as in input
a pulse that the width is varied from 0 to 2 msec. wide repeated about 30 times a second..that pulse driving circuit is very easy to implement with a pic microprocessor..Just a thought..:cheers:

Interesting...well, at least I know cheap replacements are available.

I wonder if anyone has used one of the 2000-4000watt brushless RC aircraft motors yet. :D
If I could find a way to control it, I'd do it. The idea of low-speed torque AND 10k spindle speeds is hard to ignore...but I'm spoiled by the Haas 10k spindle.

That may well be where I'm headed. I've seen pics of someone using an axi 28XX motor on one, and I have a 5330 or two kicking around, which top out around 2000 Watts. Why you'd need over 2 HP peak into a Sherline spindle I don't know, but I'd be willing to try :)
Controlling it shouldn't be that bad. I'd use one of the commonly available micro-controller boards from places like Parallax to build an "interpreter" to go from the 0-10v that the G540 puts out (or it could take step and dir if I wanted it to) and generate an appropriate pulse train for a hobby servo which is what the hobby ESC's use. It sounds bad, but the code is relatively simple to do.
There are a couple problems with this setup though. First is cost. If you have some of the stuff lying around it can be cheap, but if you have to find a power supply capable of the amperage these things demand to get to those power levels (you aren't getting 2000W without a PS that will put out ~60A). Add to that the cost of the motor and a good controller and you are right back to where you should have just gotten a cheaper VFD and been done with it.
The second big issue is cooling the motor. These kind of motors were designed to be placed in the nose of a moving airplane. They rely on cooling airflow to keep the magnets under their curie temp, so as to not lose magnetism. When you do things like use them in Helicopters, where they are relatively stationary you need to come up with ways to force air though them. This would be no different, you'd need to come up with a cooling solution, or your longer runs will end in disappointment.
I've actually built a couple of motors like this, using scrounged armature laminations from other motors, rewinding them to my liking, and redoing the magnet arrangement, switching from the stock ferrites to N45 neo's. I think the trick is to wind something like this so it will take power from a cheaper VFD, so your power supply and controller needs are handled in one box. It's the same kind of motor, 3 phase, so the base theory is sound. Once I've got my machine complete, that's my next challenge.

the rc aircraft motors are controlled by a small module that requires as in input
a pulse that the width is varied from 0 to 2 msec. wide repeated about 30 times a second..that pulse driving circuit is very easy to implement with a pic microprocessor..Just a thought..:cheers:

1-2ms wide repeated 50 times a sec, but you're in the ballpark :)

Well, I just ordered a KBIC card, and sent an email off to the Puma's manufacturer to enquire about repair costs.

I've been wanting to get into PIC and BASIC stamp programing, maybe I'll pick up a Parallax experimenter board and play with one of my brushless ESCs in my spare time. I don't have anything big enough for a Sherline spindle, but the input for a small ESC, or even a servo, works the same way. :D

Well, I just ordered a KBIC card, and sent an email off to the Puma's manufacturer to enquire about repair costs.

I've been wanting to get into PIC and BASIC stamp programing, maybe I'll pick up a Parallax experimenter board and play with one of my brushless ESCs in my spare time. I don't have anything big enough for a Sherline spindle, but the input for a small ESC, or even a servo, works the same way. :D

Do yourself a favor, get the propeller board instead of the basic stamp. $20 buys the proto board with the chip and memory pre-soldered. It offers on board connectors pre-wired for keyboard and mouse input as well as TV out. Space for prototyping too. Easy to program too, with a USB programming cord. It's not only the cheapest option overall, but far more powerful in the end than a basic stamp. I like the language too, better than PBasic, but that's a personal preference.
It's the board I would use, and if you like I can help with programming, as I said I plan to do it myself at some time. I can also do PBasic, but I'm a little rustier in that.

Nice, thanks for the tips :D

We use Basic STAMP's all day here at work to run our test equipment. Super-easy to program (which is likely why we use them), but SLOW, inefficient code, and retardedly expensive. I've blown at least 6 of the $90 BS2P40's in the last few months. They don't like static charges. I'm changing to Cypress PSOC chips (they have tons of configurable devices embedded on the chips) since we use those in products we sell and so guys here know how to program them in C, but I use Atmel parts exclusively at home. I'd reccomend Atmel or PIC any day over Basic STAMPs, unless speed or cost doesn't matter and you need to have kids program it. :)

I've got the SurplusCenter control boards mentioned above (both the old plain aluminum one and the black anodized one) but haven't done much beyond spinning a motor with them. Hopefully they're easy enough to interface with. :) Lately I've been machining at 10k RPM / 120inches / minute and feel the need for more speed though. I like the idea of a nice high speed spindle with the RC motor attached. I could go for 20k RPM as long as it doesn't sound like a screaming Banshee. (Dremel tool.) :) It's fun watching a rooster tail of aluminum spit out of the cutter!

I wonder if anyone has used one of the 2000-4000watt brushless RC aircraft motors yet. :D
If I could find a way to control it, I'd do it. The idea of low-speed torque AND 10k spindle speeds is hard to ignore...but I'm spoiled by the Haas 10k spindle.

Almost! I built a spindle with a 3 Hp Magmotor like the combat robot guys use. The spindle wasn't much good, but the motor was ferocious. I used a controller with a 5K pot, like the ones they have on electric scooters. Rated speed at 24v is 6000 rpm, and it has tons of torque.

If I could keep the motor cool, I would absolutely use it on something like the Sherline spindle.

You can control the brushless RC motor controllers with a servo tester - http://www.robotcombat.com/products/RL-SRVTST.html

Did you consider using a servo to drive the spindle? Everybody I've heard of doing that has been very pleased with their performance.

Best regards,

Jason

Almost! I built a spindle with a 3 Hp Magmotor like the combat robot guys use...the motor was ferocious... Rated speed at 24v is 6000 rpm, and it has tons of torque.
If I could keep the motor cool, I would absolutely use it on something like the Sherline spindle.
You can control the brushless RC motor controllers with a servo tester - http://www.robotcombat.com/products/RL-SRVTST.html
Did you consider using a servo to drive the spindle? Everybody I've heard of doing that has been very pleased with their performance.
Best regards,
Jason

Yes, I've thought about using a servo tester, I think I have one around here in my tons of RC stuff...
Hmmm... a servo spindle would give me instant rigid tapping ability...
Your 3hp combat 'bot motor sounds good, my current spindle setup is fan-cooled, but I guess I'd need more than just a fan... maybe a Peltier or water cooling?

We use Basic STAMP's all day here at work to run our test equipment. Super-easy to program (which is likely why we use them), but SLOW, inefficient code, and retardedly expensive. I've blown at least 6 of the $90 BS2P40's in the last few months. They don't like static charges. I'm changing to Cypress PSOC chips (they have tons of configurable devices embedded on the chips) since we use those in products we sell and so guys here know how to program them in C, but I use Atmel parts exclusively at home. I'd reccomend Atmel or PIC any day over Basic STAMPs, unless speed or cost doesn't matter and you need to have kids program it. :)

I've got the SurplusCenter control boards mentioned above (both the old plain aluminum one and the black anodized one) but haven't done much beyond spinning a motor with them. Hopefully they're easy enough to interface with. :) Lately I've been machining at 10k RPM / 120inches / minute and feel the need for more speed though. I like the idea of a nice high speed spindle with the RC motor attached. I could go for 20k RPM as long as it doesn't sound like a screaming Banshee. (Dremel tool.) :) It's fun watching a rooster tail of aluminum spit out of the cutter!


Arrgh...I think I'll wait a bit on this one. When I get into PICs it'll be for robotics, I guess I won't torture them in my mill, at least not right away. Dealing with a learning curve AND a destructive environment sounds expensive. :D

Yes, running something like a 3/4" two-flute through aluminum at 10,000RPM and 100IPM is a lot of fun... but noisy.

where was that website when i was building my battle bot? holy crap.. oh, and thoes brushless motors, i gotta get one for my RC outrigger!

i dont need to push a 3/4" endmill that fast, but i sure would like to run my 1/4" and smaller stuff, and be able to do something in the neighborhood of 50IPM, as it is now, i'm crawling at 2-3IPM(stock spindle at 2krpm

Yeah, I'm spoiled by the Haas machines at work. Sometimes it's hard to come home and 'Think Small', but it is relaxing.

I do think a servo setup would've cost less than my Magmotor experiment, and as you say - rigid tapping would then be relatively straightforward. Speed control is almost trivial then too...

A peltier big enough to remove the heat from a Magmotor might cost quite a bit? I do wonder about the internal motor temperature given they're a brushed, closed motor - the heat from the brushes and windings doesn't really have anywhere to go. I think a brushless RC motor would be better from a cooling point of view.

Having said that though, I have an electric quad with 2 of the larger 4.5 Hp Magmotors and they don't get too hot even after an hour's fun in the park. Maybe a fan and heat sink would be all that was needed?

Project5K - good site, isn't it :)

Regards,

Jason

I've actually built a couple of motors like this, using scrounged armature laminations from other motors, rewinding them to my liking, and redoing the magnet arrangement, switching from the stock ferrites to N45 neo's. I think the trick is to wind something like this so it will take power from a cheaper VFD, so your power supply and controller needs are handled in one box. It's the same kind of motor, 3 phase, so the base theory is sound. Once I've got my machine complete, that's my next challenge.

Eric, is there any reason you can see that you couldn't just use a brushless RC motor with windings for higher voltage with a standard VFD? Preferably cheaper, but something like the Neumotor 1521/3Y (110v) or 1527/3Y (140v) perhaps?

Best regards,

Jason

Eric, is there any reason you can see that you couldn't just use a brushless RC motor with windings for higher voltage with a standard VFD? Preferably cheaper, but something like the Neumotor 1521/3Y (110v) or 1527/3Y (140v) perhaps?

Best regards,

Jason

None that I can see. Provided you get something where the Kv is in the right range for your gearing things would work just fine. Neu is good stuff too.
To those suggesting Magmotors, I'm know they put out the power per size (I'm a current bot builder as well) but I think that there are many better options particularly given the cost of Magmotors. Again, if you have a couple it's not a bad option, but to those staring from scratch it's prolly not the best option as you are looking at the same high cost for power supply and speed control.
The higher voltage brushless setup with a small VFD may be just the ticket, although I still think that cooling is going to be an issue unless the motor is run well below it's rated max.

To those suggesting Magmotors, I'm know they put out the power per size (I'm a current bot builder as well) but I think that there are many better options particularly given the cost of Magmotors. Again, if you have a couple it's not a bad option, but to those staring from scratch it's prolly not the best option as you are looking at the same high cost for power supply and speed control.

Yeah, that was me :)

I agree. I happened to have all that already so I figured it was worth a shot. If I hadn't, I'd have gone servo or RC brushless.

Regards,

Jason

hi Sherline and Taig guys!
I have made different spindles, just added motors for direct drive, as well as built from A to Z all muself ... included high speed spindles 25krpm up to 50k.
Hereby I like to show direct drive Sherline I made yesterday/today for my friend.
When used 24V Power Supply (16A max.) - result was 4300 RPM, 0.3A no load current, 1A...5A with 6mm endmill, milling of aluminium (5A max when very!!! heavy cut),
Motor is my own design, stator plates 0.15mm thick, 24 tooth, 20 pole (low cogging!!!) toroid wound by cheme AabBCcaABbcCAabBCcaABbcC, 8.5 turns per tooth, 0.33 square mm wire (I use Litz);)
Motor driver: any adequate (voltage/amperage) brushless RC speed controller,
I used 40A Kontronik today, and this ESC you drive with simplest PWM generator (RC servo tester). OD-53mm, ID-38mm, h-20mm, Neodymium magnets 5x20x2mm ...
I wound this motor all windings (Aa pairs) "wires on the air" because I was not sure about result, and about what voltage will be used later ... so it was done so because to have possibilities to group series/parallel Aa pairs if it will be needed ... all windings per phase are series connected now and all togethere to Star. Switch mode power supplies I have and already tried 24V/16A, 36V/12A, I have 48V/36A large one too but was too lazy to try it ( was needed to change this Kontronik (25V) to higher V ... but I know it works well and result will be twice higher than with 24V - when 48V then max RPM 8600 and no load current perhaps bit higher than 0.6A because small losses (good materials:rolleyes: ) Today I dont know what RPM my friend will need - we see it later - at that I dont want to give away my 48V supply ... perhaps he will happy with 24V -> 4300 rpm ???????????????????????????
Of course - to do all this - some kind of knowledge must to be owned before:cool:
... and especially rotor parts must to be done precise and well balanced
It is very quiet machine now !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Regards,
Herbert

^^ That's pretty cool. You should sell plans for that, or kits.

few sketch/drawings for better understanding,
Rotor is made from strong and thick enough aluminium,
High permeability back iron for magnets is inside ...
No cooling holes - two hours continuously work - ca 30C degrees :)
Regards,
Herbert

Gladly will help everyone who want to rebuild his spindle. Mostly with advices, of course.
I dont like to "sell" my ideas - not for me, I have learned myself a lot of from this nice forum - none asked any penny - men have another ways to make the money - work:cool:
Everyone can rebuild it by own style, using different stators, inner-runner, outer ... 24T, 18T ... 12T ... I can advice when seen picture about.
Stator must to be VERY good if you like low losses, not "induction furnace"
My stator laminations I ordered especially for bit another purpose, its etched, not stamped, very precise work and was fairly expensive ... but what´s most important - the right material :cool:
Have a nice time,
Best regards,
Herbert

Forgot to tell - its third Sherline spindle I have rebuilt. First one was also outer rotor style, second was inne-runner - "normal" brushless motor where I used part of stator from burned off (very expensive when new) servo motor.
I have to tell you that outer-runner is bit more agreeable for me when RPM does on exceed 10K and when also lower RPMs with high torque will be needed. It possible with inner-runner too but then it will be much bigger by OD. At that outer rotor itself is very useful when tool changing (thats because it need to be built strong).

It's generally far easier to repurpose already made laminations into something workable than to design and have fabricated your own. I've done many such conversions, taking donor motors, stripping the factory wind, ditching the stock magnets, and redoing the bearings and such. The weapon on this guy : http://gallery.me.com/escott76#100111 is made in such a way. The disk itself became the "rotor" and had the magnet assembly built in. 3.5lbs spinning at 8k. ~6" diameter with a couple of S7 teeth. The begining of the video is a little slow, but wait till the end, it's worth it :)
I've got a bigger armature waiting in the wings, but instead of using a hobby controller and living with the limitations of it's power supply, I'm going to wind it to use a regular VFD. Still a 3 phase AC motor, so it should work fine.

Herbert, great spindle motor... I'm VERY interested in that one.

Escott... awesome 'bot. :D

Herbert, great spindle motor... I'm VERY interested in that one.

Escott... awesome 'bot. :D

At first you have to find good stator wheres ID is bit bigger than Sherline spindle shaft + enough space for fixing. OD appr. 50mm, hight 20mm up to 1" is OK.

Cheers,
Herbert

Anyone knows:
What exact bearings Sherline spindle uses?
I did check the runout of this spindle - not good at all :(
Is it "normal" for Sherline ???

Anyone knows:
What exact bearings Sherline spindle uses?
I did check the runout of this spindle - not good at all :(
Is it "normal" for Sherline ???

Don't know the bearing info, but I find it quite odd to hear of the spindle runout issue - how are you checking the runout? Sherline specs the spindle at .0002" runout at the spindle nose if I remember correctly - my Sherline spindle is consistent with this figure - impressively accurate and rugged little spindle for its size and price.

From the Sherline industrial site -

Runout at spindle nose: .0003" or less
Runout at 3" out from spindle nose: .0005" or less
End play at factory preload setting: .0002" (preload is adjustable)

As you can understand - it is not my Sherline. At first I wonder when installed my Baer precision Bohrfutter (drilling chuck) and saw the runout with my own eyes! :eek:
(Bohrfutter Super 0,0 - 6,0 Kegel B 10 BAER-Super-Schnellspann-Bohrfutter Rundlauf 0,03mm Hochpräzises-Präzisions-Ganzmetall-Bohrfutter der Spitzenklasse mit Innenkegel DIN 238)
->MK1 from same company... never flapped on my machines!
OK - perhaps my old eyes himblerig me ... :(
Then I cleaned on time more mk taper and tried with 6mm original Sherline collet and 100mm long 6.00mm rod, measured runout from 5mm - was 0.02, 50mm - was 0.07 mm, end of rod even 0.09mm ... felt e'en with fingers.
Perhaps its damaged .. who knows ...will see ...
Its not a big problem for me because not my machine,
But week ago I already ordered a new Sherline headstock for making one more spindle, and planned to change bearings to SP angulars for higher speed,
Thats because wrote bit worryingly about Sh. quality
I hope this excuses me :rolleyes:

Regards,
Herbert

PS:
Bearings type and sizes I would like to know anyway:)

The collet likely has as much or more runout than the spindle itself (stack .008mm for the spindle and .008mm for the collet and you get .016mm) - I have never used the Sherline collets(never even saw one), so this is pure speculation. Maybe you have .04 mm runout in the rod as well?

The collet likely has as much or more runout than the spindle itself (stack .008mm for the spindle and .008mm for the collet and you get .016mm) - I have never used the Sherline collets(never even saw one), so this is pure speculation. Maybe you have .04 mm runout in the rod as well?

No! This rod is extreme precise, like benchmark etalon.

I dont know much about Sherline collets but ER11 (my high speed spindles base on) ... yes, there you can find frustrating syrprises. Every time when buy a new set of, I need to check and cull out bad ones, or even impelled to throw away all. Maddening that does not matter you bought expensive or cheap:mad:
cheers,
herbert

At first you have to find good stator wheres ID is bit bigger than Sherline spindle shaft + enough space for fixing. OD appr. 50mm, hight 20mm up to 1" is OK.


Does anyone know where to start looking for something like this? I don't have the know-how to make my own motor, and I'm not really wanting to just start buying motors and taking them apart to see if they can be adapted... thanks.

Does anyone know where to start looking for something like this? I don't have the know-how to make my own motor, and I'm not really wanting to just start buying motors and taking them apart to see if they can be adapted... thanks.

I find most of mine surplus, although as you say it's hard to know what's what. There is a group on Yahoo groups the "LRK brushless" group that has lots of info. They are generally talking about one particular wind type, but there is info there on many. I've picked up several cheap donors through reading there where people got theirs.

I find most of mine surplus, although as you say it's hard to know what's what. There is a group on Yahoo groups the "LRK brushless" group that has lots of info. They are generally talking about one particular wind type, but there is info there on many. I've picked up several cheap donors through reading there where people got theirs.

You correct - there is tens of different ways you can do it.
Surplus/scrap/stores, or some friend who has in garage "all" , This motor from where you can find fits for stator for your first try could be damaged, burned off - does not matter. Older PC storages has large stators (somes even too large) you need several to make at least 20mm hight. Many printers use appr 2" outerrunners you exact need, for example 5013 laser printer :banana:
I had/have a lot of this kind of stuff, unfortunately shipping cost will not make you happy:mad: Myself I dont use those poor materials anymore.
Im sure that some RC larger outerrunners are also good, perhaps cheap Chineses from ebay .. or used/crashed ones.
NOTE !!! -> ID ... its sometimes possible to enlarge when bit too small. Sherline shaft is ca 14.3mm + few mm for suport tube ... airgap ... 20mm of id could be enough. Some rc pages sell stators or just laminations - ask some friend or rc forums.
;)
Cheers,
Herbert

HEADSTOCK BEARINGS
Designation/stock number (ZZ refers to "double shielded") 6004ZZ
Size of bore 20 mm (0.7874")
Tolerance of bore 0.0004"
Outside Diameter 42 mm (1.6535")
Tolerance of OD 0.0005"
Width 12 mm (0.4724")
Bearings 9 balls, 1/4" dia.

Hmm ... very modest choice :rolleyes:
I have same size SP angulars, different brands,
seems will replace when my own Sh. headstock arrives,

regards,
herbert

thanks for the tips guys. I actually work at a hard drive company so I can start experimenting with bldc motors pretty easily, but I'm not into RC stuff so not terribly familiar with all of the commercial stuff available. I've started doing some research though, and it's all pretty fascinating. I know some motor designers at work, so I might pick their brains, but I also know a few helicopter flyers and I suspect they'll be a better place to start for practical knowledge. So while I didn't really want to get involved in diy motor building, maybe that's where this hobby will take me next.

thanks for the tips guys. I actually work at a hard drive company so I can start experimenting with bldc motors pretty easily, but I'm not into RC stuff so not terribly familiar with all of the commercial stuff available. I've started doing some research though, and it's all pretty fascinating. I know some motor designers at work, so I might pick their brains, but I also know a few helicopter flyers and I suspect they'll be a better place to start for practical knowledge. So while I didn't really want to get involved in diy motor building, maybe that's where this hobby will take me next.

Electric heli pilots are a good source, I have a couple helis that I fly regularly. A heli is very similar to a mill in that you want to keep the head speed constant even though the load will change due to pitch changes or cyclic inputs. You want the mill spindle to behave the same way. Beware though, as good heli stuff is not at all cheap. I will say this though, if you do go down the hobby route, get the best controller you can afford. The kontronik mentioned earlier is an awesome controller. It doesn't have the fancy settings of some of the others with programming cards or similar, instead it just works, without messing with it.

Heli mode constant speed does not want to work perfect when you use
ServoTester->ESC->Motor. When you try via RC Radio -> Receiver->ESC->Motor - then it does better, then you can order needed RPM via Radio. By Programming card ... its also too anfractuous. I think that some kind of circuitry need to be added. I have the best RC stuff whats possible but unfortunately my knowledge about electronics is too low. Hopefully somebody will help.
Cheers,
Herbert

Hereby some more ideas about useful stators - reel ... capstan motors (Teac, Studer ...), you can find really cheap (eBay Item number: 400030770708 for example) These are induction motors, you need to remove all windings and then wind it own.
Before to wind it you need to enlarge ID and lessen OD - it is not a problem for machinists. Lessen OD because you need the room for ca 2mm thick magnets if you like to use these outer rotors (good material), 1mm lessen from OD of Stator and 1mm from rotor inner surface ...
Lessening OD od stator - you must to be clever and smart enough to not ruin it (chair)
Hight of Stator you need to keep 20mm or similar - depends about lenght of magnets you planning to use.
Mechanical design - everyone can do own, I hope so.
Windings ... there is enough room for what ever style and configuration.
Smarter is to use low cogging conf. - 24 tooths - you can use schemes:
24/20 AabBCcaABbcCAabBCcaABbcC
24/22 AaAabBbBCcCcaAaABbBbcCcC
24/26 AaAabBbBCcCcaAaABbBbcCcC
24/28 AabBCcaABbcCAabBCcaABbcC

Regards,
Herbert

Or you can use this 12 tooth stator from Printer motor I have spoken before,
Sizes: OD-50.2mm.
ID is 20mm - near OK for suport tube wheres Sherline shaft inside ....
But its not a problem to make it larger.
Height is 13.7mm - I prefer to use two stators for making 20mm or 25mm of height.
There rotor needs 10 or 14 magnets for low cogging, scheme:
12/10 and 12/14 - AabBCcaABbcC
Better to use two magnets per pole like SS-NN-SS .... when using ca 5mm wide magnets. I dont recommend to use mach widder than 6mm flat magnets because geometry ... hopefully you understand what I mean:o
Few years ago these motor units was on sale in many surplus shops- cost was ... as I remenber I bought 6 for $28

Heli mode constant speed does not want to work perfect when you use
ServoTester->ESC->Motor. When you try via RC Radio -> Receiver->ESC->Motor - then it does better, then you can order needed RPM via Radio. By Programming card ... its also too anfractuous. I think that some kind of circuitry need to be added. I have the best RC stuff whats possible but unfortunately my knowledge about electronics is too low. Hopefully somebody will help.
Cheers,
Herbert

I wasn't suggesting that anyone use the governor mode (as it is commonly called here), as it serves a different purpose on a hobby ESC. I was more trying to say that helicopter pilots, at least those who know their stuff, are selecting motor and power systems similar to what we want. A total system with enough power in reserve to make up for changes in load. They also understand how to take a motors given Kv and gear it appropriately so that it stays in it's power band at max power output given the final RPM. Conversely they can probably suggest a motor that will fulfill a given RPM need with a particular gearing.
Personally the whole use a servo tester to control a hobby esc sounds pretty clunky to me. I know there aren't a lot of other off the shelf options, but there are relatively simple to make options. There are so many flavors of cheap, easy to program micro-controllers out there these days that making your own interface board would be cake. Personally I'm partial to the Parallax propeller board http://www.parallax.com/Store/Microcontrollers/PropellerDevelopmentBoards/tabid/514/CategoryID/73/List/0/Level/a/ProductID/423/Default.aspx?SortField=ProductName%2cProductName
which is relatively inexpensive, super powerful, and easy to program. If I wind up going the hobby controller brushless route, this is the board I'll be using.
The whole idea of using a hobby controller seems inefficient to me. You have to get a power supply with significant amperage and reasonable stability to make the controller happy. These things were designed to run on batteries which are a constant power source, no AC ripple. That power supply costs a good bit. Then you need a decent controller to run it, which also costs a good bit. I'm aiming to cut out the middle man, and since I'm winding the motor myself anyway, I might as well wind it for a higher voltage, lower current, and use a small VFD. The VFD will cost way less than the hobby controller and PS combined, and is designed with an interface that CNC controllers know how to talk to.

You right ... and not right at the same time.
Some kind of disdain I do forgive - Im old enough for understanding. English is not my mother tongue and its poor - because my messages feels inarticulated. But OK - it does not matter much.
RC ESCs you can buy for $10...$1000 - your choice. Heli mode or Governor mode when ESCs - both widely used - however most of all like heli mode. I have been busy with RC stuff last 15 years and brushless speed controllers I have perhaps more than 50 - as well as motors - even not necessary to count - huge lot of!!! I dont fly myself anymore, my son does. I have used and using ESCs everywhere whats ever possible. When max Amps are 40...120 it does not mean you use it when motor takes just only few. At that low amp ESC available as well, costs near nothing. Power supplies I use are unexceptionally switsh modes and mostly I use not overdimensoned by power , perhaps choiced +10A after tested.
Power wires could be much longer as described in user manuals. My high speed (50kRPM) spindle has 1.8m lenght of wires. Some kind of experience and knowledge are welcomed when you like to try.
PWM generator (servo tester) is the simplest way to drive. There are good ones for few $ in ebay. Some kind of interface will needed for fixed RPM - its clear. Im not able to do it myself - also clear - but I have not just only spoken like fews - I have DONE in reality!
Dont worry,
Regards,
Herbert

You right ... and not right at the same time.
Some kind of disdain I do forgive - Im old enough for understanding. English is not my mother tongue and its poor - because my messages feels inarticulated. But OK - it does not matter much.
RC ESCs you can buy for $10...$1000 - your choice. Heli mode or Governor mode when ESCs - both widely used - however most of all like heli mode. I have been busy with RC stuff last 15 years and brushless speed controllers I have perhaps more than 50 - as well as motors - even not necessary to count - huge lot of!!! I dont fly myself anymore, my son does. I have used and using ESCs everywhere whats ever possible. When max Amps are 40...120 it does not mean you use it when motor takes just only few. At that low amp ESC available as well, costs near nothing. Power supplies I use are unexceptionally switsh modes and mostly I use not overdimensoned by power , perhaps choiced +10A after tested.
Power wires could be much longer as described in user manuals. My high speed (50kRPM) spindle has 1.8m lenght of wires. Some kind of experience and knowledge are welcomed when you like to try.
PWM generator (servo tester) is the simplest way to drive. There are good ones for few $ in ebay. Some kind of interface will needed for fixed RPM - its clear. Im not able to do it myself - also clear - but I have not just only spoken like fews - I have DONE in reality!
Dont worry,
Regards,
Herbert
I know english isn't your first language, and there is no disdain here. Don't forget, you aren't the only person who has "Done in reality", as I have as well. I know better ways to do some of the things you describe, as I have done them in reality. Some things I still have yet to try, but please don't tell me I'm "not right" as you haven't seen what I've done either.
I stand by my statement that RC ESC's and the power supplies they require for the kind of power we want to generate are not cost effective. Perhaps for 50k spindles you can get away with a cheaper supply, but I want to get maybe 10k max, with plenty of power to use common size em. The $10 ESC's are available, but are quite simply crap. I've seen too many fail outright or give such sketchy results that I'd rather just spend the money once and get a good one. I need a reliable system, and there are better and less overall costly ways to get it.

The VFD idea is interesting, I don't know much about them. Does a VFD work with a brushless dc motor, or does it require a different sort of motor winding? I don't know much about the differences between AC and DC brushless motors or AC motors or induction motors. Time to start learning I guess.

I've used $1000 sensorless bldc motor controllers at work for spinning HDD spindles (the thought of using it for CNC purposes never crossed my mind). I would like to understand the difference between a $10 ESC and a $1000 Eloquent Designs or Xyratex Xyclone BLDC controller. Certainly the software interface is part of it. How accurately can an ESC hold a specified RPM? I've done some work with the Microchip bldc motor board as well (uses dsPIC30 uc). I like the PICs- inexpensive development tools and seemingly infinite amount of code examples (in C no less) out there.

One more idea:
eBay Item number: 220222374955
http://cgi.ebay.com/Precision-Bi-Directional-Brushless-DC-Motor-w-Driver_W0QQitemZ220222374955QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item220222374955&_trksid=p3286.c0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A0%7C293%3A4%7C294%3A50
I have no idea how this original controller works, is it possible to "parallel" several units or not ... myself I prefer RC sensorless ESC ... but someone whos able can try it - perhaps very good:banana:

Main idea is to stack together needed number of stators (18 tooth) for getting adequate hight and rewind it by scheme
18/16 - AaABbBCcCAaABbBCcC
or /the same
18/20 - AaABbBCcCAaABbBCcC

Inner Rotor 16 or 20 pole I strongly recommend to make a new, using Neo magnets.

Have a nice time,
Regards,
Herbert

The VFD idea is interesting, I don't know much about them. Does a VFD work with a brushless dc motor, or does it require a different sort of motor winding? I don't know much about the differences between AC and DC brushless motors or AC motors or induction motors. Time to start learning I guess.

I've used $1000 sensorless bldc motor controllers at work for spinning HDD spindles (the thought of using it for CNC purposes never crossed my mind). I would like to understand the difference between a $10 ESC and a $1000 Eloquent Designs or Xyratex Xyclone BLDC controller. Certainly the software interface is part of it. How accurately can an ESC hold a specified RPM? I've done some work with the Microchip bldc motor board as well (uses dsPIC30 uc). I like the PICs- inexpensive development tools and seemingly infinite amount of code examples (in C no less) out there.

Hey, if you're comfortable with PIC's so much the better. I suggested the Parallax route as it's friendlier to people with no experience.
There are no brushless DC motors*, although the source of power for a hobby motor is DC, the motor is running on 3 phase AC which the controller generates. Hell, even the so called permanent magnet DC motors are switching directions by use of the commutator. Anyway, there is little difference between a VFD and a sensorless brushless controller.
One of the main differences in controller is the software, how well it's written, how smooth it scales power to the motor, how well it holds under load all kinds of other goodies. Anyone can slap together a board with datasheets, but it takes talent (money) to optimize it so it operates to higher tolerances. Just like just about everything else.
You sound really well setup to try something like this, with resources few of the rest of us have. Good luck and keep us updated, let me know if I can be of any specific help.


*on several technicalities there are, but they are not that common in use. Pure DC motors are relatively rare, although a common place to find them is the older rotating disc power meters. There is a "Handbook of Electric Motors" that contains all sorts of useless interesting factoids.

Dear escott76,
Sorry, but I will not to thrash out with you about who is better or smarter - not for me - hopefully at least 23 years later you will think identically:argue:
Cool down,
If you have something to show - please do it.
cheers,
herbert

There are no brushless DC motors*, although the source of power for a hobby motor is DC, the motor is running on 3 phase AC which the controller generates.

Hmmm, interesting. I figured there must be a difference between AC and DC motors or they wouldn't have different names. To me, AC implies sinusoidal voltage vs time, whereas DC is PWM'd when "on" and 0v when off. Again, I need to do some more research. Maybe a coil is a coil and doesn't care quite as much as an engineer does about what the input waveform looks like.

So do VFD's pwm the motor phases the same way and look for back-emf on the non-powered phase? When a VFD spec's a frequency range (like 10-400Hz), what does that mean?

Herbert- thanks again for the links and tips.

Hmmm, interesting. I figured there must be a difference between AC and DC motors or they wouldn't have different names. To me, AC implies sinusoidal voltage vs time, whereas DC is PWM'd when "on" and 0v when off. Again, I need to do some more research. Maybe a coil is a coil and doesn't care quite as much as an engineer does about what the input waveform looks like.

So do VFD's pwm the motor phases the same way and look for back-emf on the non-powered phase? When a VFD spec's a frequency range (like 10-400Hz), what does that mean?

Herbert- thanks again for the links and tips.
Think of it this way, what is commutation but AC? If you were to feed straight DC into the armature it would move to the position where opposite poles line up and lock there. Only by switching as the motor spins are you able to get rotation. Brushed motors use brushes to do it, and brushless go without (duh :) ) but make no mistake, hobby brushless motors are 3 phase AC motors. You can view the sinusoidal waves on a scope.

Hmmm, interesting. I figured there must be a difference between AC and DC motors or they wouldn't have different names. To me, AC implies sinusoidal voltage vs time, whereas DC is PWM'd when "on" and 0v when off. Again, I need to do some more research. Maybe a coil is a coil and doesn't care quite as much as an engineer does about what the input waveform looks like.

So do VFD's pwm the motor phases the same way and look for back-emf on the non-powered phase? When a VFD spec's a frequency range (like 10-400Hz), what does that mean?

Herbert- thanks again for the links and tips.

When BLDC, like RC motors and most of brushless motors, then controller does not "generate" - controller, sensored or sensorless - does follow rotor position - instead of brush commutator you have electronic commutator,
whereby electronic commutator gives much more possibilities to play with number of slots versus rotor poles - commonly higher number than 4 of magnet poles you do not see when brushed motor because room limits for more brushes. Simplest two pole / "three leg" armature dc brush motor is equivalent of 2 pole / three tooth brushless motor - 3phase motor :)
Brushless DC motor is most common brushless motor - does not matter it has what design - slotless_ironless_airgap ... axial, radial ... outer rotor, inner rotor. When it is commonly designed as 3phase dc brushless, then anyway it is DC motor, it could be maden as 2 phase, 5 phase ... what ever.
Mostly used trapezoidal waveform, sometimes sinus as well, but even when sinusoidal, its not "generated" - faster synthesized.
When AC brushless then electronic commutator commutates pure AC current. Mostly these are higher voltage motors ... hopefully you have seen "normal" brushed AC motors :)
Motors where controller "generates" are induction motors, variable frequency ... these are AC motors ...asynchronous like hf spindles, variable f servos what could be as synchronous as well as asynchronous ...,

cheers,
Herbert

http://www.townbiz.com/wd/clients/examples/resmed/2-pole_bldc_motor.html
http://users.tinyworld.co.uk/flecc/4-pole-bldc-motor031102.swf
http://users.tinyworld.co.uk/flecc/brushless_motor.html