Hello!

I recently bought a Optimum BF-20 Vario mill and intend to convert it to CNC! :)

So far i have only made the mounting plates for the x-axis and will start making the y-axis tomorrow... I'm going to use the standard leadscrews to begin with so i'll make my own custom Oldham type couplers as you can see in the pictures.

When i get the mill running under CNC control i will make better stepper mounts and replace the bearings with angular contact ball bearings. And later i'll buy ballscrews. I don't want to start with that because i have to modify the base and the y axis carriage to fit the nuts.

I'll take some photos when i have made the couplers! :)

/Jay

Hi,
I am making a set for converting the BF20 to CNC as well. I have finished my initial designs, have included some pictures of it. The kit will become available at www.damencnc.nl after testing is finished. The parts will be made from laser cut stainless steel plates. Covers are in the making so work can be done with coolant.
I had some question about your design, which is interesting:
Are you using the motors coupled directly to the axis? Don't you have problems with resolution? Even with microstepping, a direct connection often causes problems unless huge steppermotors are used.
I am using belts so that smaller motors can be used... Have runs mills like these with 1.5 to 2nm motors and they work great..

Greetings, Kevin

Yes i'm doing a direct coupling... Its just a temporary setup that i can make all parts on the manual mill :) I have read that steppers is best with direct coupling because of the torque curve.. You don't gain so much (if nothing) with gearing because the stepper have to run faster and the torque of it goes down.

I have 2,2Nm steppers and plan to counterbalance the head to be able to use them for Z too! (not the fine feed)

/Jay

Here is some pictures of the mounting plates (The front Y plate is not shown)! This is the first parts i have ever made on a mill so they are not pretty :) But then again... Its only temporary parts until i get the mill converted. Can't wait! Hate to turn those hand wheels :)

/Jay

By the way... I really need to build a bench for the mill... The table that i use now is very unstable, and i didn't want to drill bolt holes in it so i just clamped the mill to it with MDF boards :)

been using a stepper converted opti BF20 for about 2 years now:
http://www.anderswallin.net/2004/11/07/cnc-milling-of-mdf-plug/

note stack of counterweights we use behind the machine as we have coupled the Z-motor to drive up/down the whole spindle box.

the DC motor burned out during a longer run so had to replace it
http://www.anderswallin.net/2005/11/27/motor-mount-for-new-opti-motor/

I find the stock leadscrews and the dovetail guides are really limiting the precision that can be achieved. With backlash compensation it now runs accurate to about +/- 0.05mm in the Z axis and probably a little better for X and Y.

another problem is the center accuracy of the spindle. we now have something like 0,05mm of eccentricity which is no good for vibration/surface finish.
this might be way better on a new machine as we have done maybe 10-15 long (4-5h)runs in steel/alu which might have damaged the spindle or the bearings a little...

If I remember correctly the steppers are 280 Ncm torque and they are driven by geckodrives running off a 70 V powersupply.
max feed when cutting wood is about 1000mm/min, for aluminium 300-600mm/min with very light cuts.

well, I guess you get what you pay for. I think we paid 1300eur or something for the mill, MK2 collets, some endmill, fixture kit etc...

I'm now planning a new bigger machine with linear guides+ballscrews...

I have seen your page before! :) I'm not planning on using this machine for very long... One of the major reasons i bought is was to be able to design and build linear actuators and structual parts for a hexapod... Perhaps i sell this when i'm done :)

/Jay

I made the torque disc and one part of the coupler today, nice fit to the leadscrew/key and the disc... Should be no backlash in the coupler when i'm done! :)

Hey, this is nice.

I'm also working on a BF-20 CNC conversion. I'm going the Servo way using homebrew servo controllers (http://www.cnczone.com/forums/showthread.php?t=14217)

I may be using 1:3 reduced Dunkermotor 63x55 on the X and Y axis and a 1:3 reduced Dunkermotor 80x80 on the Z axis. Another option is to leave the planetary gearboxes (1:7) on and use them that way.
Dunkermotor 63x55 is 100W 3500RPM 0,27Nm continuous
http://www.dunkermotoren.de/data/technical_data/motors/pdf/GR%2063x55.pdf#page=1
Dunkermotor 80x80 is 240W 3500RPM 0,62Nm continuous
http://www.dunkermotoren.de/data/technical_data/motors/pdf/GR%2080x80.pdf#page=1
They run @ 40V and have 500CPR encoders which gives me a theoretical resolution of 6000 pulses per main spindle revolution. When the conversion is complete I'll have built in 16x5 Ballscrews in X and Y and 25x5 ballscrew in Z giving me a resolution of 0,001mm. Which is way more than the accuracy of the machine.

Conversion will first use the standard spindles and when all is working the way I want I'll get me those $$$$ ballscrews.

When completely done I'll be able to get rapids up to 6m/min (100mm/s). With the planetary gearboxes this should still be 42mm/s which is also more than adequate.

I'm still deciding which way to go. The gearboxes are quite heavy. To hang those from the table is not very desirable since it may start to hang causing extra wear. Motor with gearbox is 3,4kg!

Decisions, decisions, decisions....

I'll see how this thread goes.

Erik Jan

What ballscrews/nuts will you use? I made a solid model of the mill to try out the possibilities of ballscrew conversion and there is not a lot of space! :P Will you modify the Y "carriage"? and/or the base? I have been thinking of trying to build DIY rollerscrews that would fit the current space! :)

Interesting about the controller! To bad i already have the steppers hehe :)

I'll use Isel ball screws.
If you can read German I suggest you read the thread
"Optimum BF20 Vario gesucht, gefunden!" in Hobby Machinen on www.cncecke.de registration required.
You'll find a wealth of information regarding the machine including mainetance, bearing replacement, ballscrew conversion, cnc conversion both with steppers and with servo's.
Their is a complete documentation of a ball screw conversion including photo's by Thomas74 that I recommend you read.

Erik Jan

Hi Erik Jan,

Dunkermotor 63x55 is 100W 3500RPM 0,27Nm continuous doesn't sound like a lot for 240 inches/min on a BF20. Also what about backlash in the gear reduction system.

Or do I misundestand something.

Phil

It will have a reduction of 1:3 or 1:7 (haven't decided yet). With 1:3 this makes about 0,9 Nm continuous torque (not just holding torque) but real usable Nm's
At 1:7 its about 2Nm which should be plently.
Backlash is almost impercievable (do you write that like this???) in the gearboxes. And it will be a constant backlash since the wear in the gears will be immeasurably small. This makes it just a setting in the software.
Starting torque (comparable to the holding torque of steppers) is 2Nm for the 63x55 and the 80x80 has 6,2Nm.

Erik Jan

I have been browsing that forum before (just for pictures as i don't read German) hehe :)

What do those motors cost?

New around E300,- each but I bought myself a bucket full (4xDunker 63x55 (with 1:7gearboxes) and 1x Dunker 80x80 (with 1:20 worm gear) ) with 3 500CPR (2000 pulses per rev) encoders for E25 or something like that.
It's a matter of what available I guess.

Check ebay for DC Motor or dc servo and encoder to check prices.

Erik Jan

Changed to a better worktable! :) Not as stable as i want but it was free ;)

I really need to get started on the controllers!

(As you can see on the windows its pretty cold, -35 Degrees C :()

-35degrees brrr..

doesnt that bother your mill ??

nice work y the way

i'll be beginning my project somewhere in februari.
i'll be sure toopost some pics by then

Its about 8+ in the garage when it is that cold outside... Like working in the fridge ;) I will order the electronics as soon as i get a little cash over :) Need to fix the pc too!

/Jay

could working in a cold(0degrees celsius) environment hurt machinery

thats funny jbv i got the pc and the machine but no steppers yet
we should a teamed up

Hey Irondigit,

We too could team up. Got a HBM BF20 and live in the Netherlands too.
Got the machine, the servo's and the first controllerboard ready.

Anxious to see it running.

Erik Jan

Check it out

http://www.top-maschinen.de/maschinen/opti-cnc-steuerung-umbausaetze/index.htm

Hi everyone
I am in France, and i also have a BF20L since beginning of 2006
I am planning a cnc upgrade, i wait for the bipolar controllers from US
I made a iron block counterweight, to help the Z axis to move easier

I'm thinking of using a gas spring for counterweight... But i probably go with counterweight to begin with :)

1 axis (X) under cnc control! :D

Made a ugly oldham type coupler.. It works very well, can take pretty much misalignment! But i probably will make my own XL timing pulleys and better mounting plates when i get Y controlled.

I'll take a picture later, spent all night trying to make the coupler in alu, just to find out it wasn't able to clamp over the stepper shaft. Had to redo the part in nylon. And now i need some sleep! ;P

/Jay

Still waiting for the controllers, so I had time to make a RPM gauge ...
Max speed : 2700 rpm, if I set the adjuster to max, the rpm stall and is not regular ... Is it the same for you ?

If anyone interested, I can give the pcb and hex files (using a pic16f628, a IR reflector with the half pindle painted in black)

Still waiting for the controllers, so I had time to make a RPM gauge ...
Max speed : 2700 rpm, if I set the adjuster to max, the rpm stall and is not regular ... Is it the same for you ?

If anyone interested, I can give the pcb and hex files (using a pic16f628, a IR reflector with the half pindle painted in black)

I am interested in these files, what did you use for the LCD viewer?

The Lcd is a "classical" 2 * 8 , serial connection, you can use any other set for direct pic usage
I post the eagle files for the electronic shemas , i'll post the hex file for the pic16f628 later

so if i got this thing right
using steppers/servos with some extra torque hold the table in position instead of the usual manualbrakes right ?

but then wont we be needing qite some torque on the z-Axis of this machine if we uppered and lowered the whole spindlehead

cuz mine got quite a heavy z-Axis compared to x-and y-axis

man that digital rpm thing looking good from way over here

keep up the good work men i think i m actually learning something over here

Steppers have what is called a holding torque. This means that the stepper is powered even when stopped. Keeping current through the same windings makes it resist motion. Holding torque is a peak torque. It can only be reached when the motor is not rotating.
Servo's use feedback. The encoder on the back tells the controller that there is a socalled error. Depending on the magnitude of this error and the PID settings of the controller the controller tries to correct the error. In an improperly set servo controller this may lead to oscilating. The controller overcorrects an error resulting in the servo overshooting it's desired position.

This is also one of the major advantages of servo's over steppers. They sense their position is off. With steppers the only thing you can do about it is stuck on a big stepper with sufficient holding power. During movement the torque of a stepper is lower than the holding torque. If the available torque is less than what's required for the movement results in slip or better lost steps. If you loose steps with a stepper the endresult will suffer. If a servo looses steps it will correct the because of the feedback.

So much for stepper/servos.

Does the head of your machine drop down when you don't clamp down the head on the ways. If yes it's not self braking (ball screw) of no it's self braking. This means that the motor can drive the head but not the other way around.

Since were talking about a stock bf-20 here your leadscrews a trapezoid / acme and thus self braking.

Erik Jan

Finished Y and made my first cnc:ed part ever! :)

:banana:
Great !!
What kind of motor do you use, and which controller ?

A 4 axis Xylotex board and 2,2 Nm steppers

I have to little money for the moment to buy stuff to convert the Z axis. But then i got this crazy idea: I will make MDF gears to drive the axis hehe :)

Hello

@manurc

Can i have the files, too ?

Greetings, Frank

Hey Frank,

Look at post #27.

Erik Jan

What´s about the Hex-File ?

Manurc wrote: i'll post the hex file for the pic16f628 later
Attached Files

Greetings FRank

What´s about the Hex-File ?

Manurc wrote: i'll post the hex file for the pic16f628 later
Attached Files

Greetings FRank

hoops !!
Sorry, i forgot to send it ...
don't hesitate to send me a private message if I still forget ... (the files are in a notebook that I don't often use)
gona try to send it this evening

Here it is ;-)
hex files for 16f628

This is not my conversion but I am working on a similar setup.
I find this very inspirational.

http://www.dirt-page.de/metall/cnc/umbau1.htm

Erik Jan

These look like really nice little mills guys! You can have a lot of fun with one of those. I particularly like the wood gear cutout as a first cnc run. Kinda makes me wish I'd started out with a smaller mill that would be easier to convert.

Very cool!

Best,

BW

I'm thinking of getting a gas spring to counterweight the head. Is it nessecary to "keep it symetrical"? Or can i use just one gas spring on the right side of the head? Will it wear out the dovetails faster? :P

I think it doesn't have to be symmetrical.
A cheap alternative, that may be easier to optain and maintain is a simple pneumatic cilinder (ebay) and an air tank. If you pick a smaller cilinder and a larger tank you'll have very little pressure increase in the stroke.

You can also use a counter weight.

I intent to use no such thing. The weight of the head takes out any play.

Erik Jan

I don't think the stepper will move the head without help :) (or some serious gearing). I have only 2,2 Nm :P

http://www.danahermotion.com/design_tools/sizing_selection.php

You can download a little piece of software here for free (the highest in the list) in which you can virtually build a motion mechanism (like a leadscrew mechanism with dovetails) and calculate what motor you need. How many rpm and torque you'll need for given speeds. You can see what the effect of a different transmission will be, different pitch, etc, etc.

Has a built in database for DC Servo, AC Servo and steppers.

I found it very easy to work with and best of all....
.
.
It's free for personal use!!!

Erik Jan

Does anyone have any info on Dunkermotoren Type GR 63x55 SNR 88442 01278 1500rpm.so l don`t know how much torque they have ..
l cannot find anything about these motors and l can buy these really cheap maybe there is a good reason for the low price !!!

Have you looked here:

"http://www.dunkermotoren.de/default.asp?id=9&mid=12&gid=0&cid=0&bid=0&sid=0&lang=2"

lots of info but appears to be 3,000rpm

Phil (chair)

Does anyone have any info on Dunkermotoren Type GR 63x55 SNR 88442 01278 1500rpm.so l don`t know how much torque they have ..
l cannot find anything about these motors and l can buy these really cheap maybe there is a good reason for the low price !!!

They are standard 3000 (~3500rpm) motors but can be customized to specific needs. They are very good motors! I have 4 of them and would like to have more. http://www.dunkermotoren.de/data/technical_data/motors/pdf/GR%2063x55.pdf#page=1
They are 100 Watt motors with 0,27Nm contiuous torque and a peak (starting torque of 2,1Nm at 3500rpm). At 1500 rpm the torque doubles making it about 0,6Nm.
There is a but however.
Since they are DC motors they cannot be controlled with a normal controller.
I'm building UHU servo controllers for them (see my thread in the open source controllers "diy servo controller")

The 1500Rpm is great for BF20 control (x and y axis) since you only need a small reduction. I'd say buy them if you can use them, if not give me the adress ;-)

Succes ermee,

Erik Jan

l purchased 2 today and l`m going to buy 1 more next week and l`ll ask if he can get anymore so l`ll let you know ..

Glen

Z-axis may need something stronger for good speed. I have an 80x80 (240W) for that. If you can get more than you need, email me, I might be interested.
Where do you live in the Netherlands and what are your plans with the motors.

Erik Jan

l live in gelderland near Lochem ...l have just purchased a BF 20 Vario mill and l want to make it into a cnc but this cnc thing is all new to me L do a lot of 2D/3D drawing at work and at home and l do a lot of my projects and working with steel, alu etc is no problem but my electronic knowledge is limited ...so l could use all the help l can get l was thinking of buying a kit from damenCNC or stappenmotor.nl but l saw these motors just sitting thereand l`m a real sucker for a challenge...

glen

The mechanical part is easy.
http://www.dirt-page.de/metall/cnc/umbau1.htm

This is a conversion that you can follow.
Reduction can be less (say 1:2 or 2:3) depending on the spindles you'll use.
Allthough expensive everybody does recommend a conversion to ball screws.
I'll use HTD timing belts since they have no backlash and are easy to obtain.
If you are quick I'll order some for you at Maedler.de. They are cheap (50% less than what I'd pay for them here in the Netherlands) with stuff like this. A guy in Germany is willing to order some for me and ordering 4 is just as easy a ordering 8.

I got my Z-axis spindle cheap and convert that right away. I'm stil in doubt if I'll convert the other 2 axis right away. I may start out using the original spindles.
Ball screws have a much higher efficiency (~90%) than acme or trapezoid (~50%), and their backlash and wear are minimal and constant whereas trapezoid will wear out the nut much faster.

Electronics can be either very easy or a bit more chaanging.
Easy with those Dunkers is buying Geckos (320 or something like that)
More challenging (but more rewarding imho) is building those UHU controllers.
Check the UHU controller subforum @ www.cncecke.de for more info.

Power supply is easy.
Buy yourself a big torriod (sec voltage around your motors nen voltage).
Most torriods have 2 secundary windings. Find out what the start is of each winding and hook them in parallel. Hook up both secundaries to an equalizer bridge (gelijkrichter) and hook the gelijkrichter to a bank of capacitors.
My setup is 2 500VA torriods 39V secundary (with 40Volt dunkers). I've switched the secundaries of each torroid together and fed each torriod into it's own equalizing bridge. After the equalizer bridges I've switched them in parallel and hooked the up to a capacitor bank (54000uF at 63V).
To prevent my fuse blowing I've added an NTC into the circuit for the primary winding of each torriod. At normal temperatures they have a certain resitance value. As current flows trought them they heat up (and get very hot). As they heat up their resistance drops to virtually zero ohms. Torriod transformers draw a very high current when switched on. This prevents that peak. After a few seconds I bypass the NTC's allowing them to cool and readying them for the next start.

This setup give me a DC power supply that generates 52V without load. With maximum load (~26A) the DC voltage will be around 42V DC.

This is enough to allow for some hefty peak current for the DC motors.


Erik Jan

Sorry this is a bit offtopic, but where can you get one of these mills in the US? They look very nice.

Hello EveryOne
Finally, the X Y cnc works (Z need still developpement ...), using USB connection

Looks nice, USB? what controller are you using(computer program)?


Jon

Hello
I made the software, the USB device is IOWarrior 24 input-output(http://www.codemercs.com), output info are the same as using parallel port
1 byte for impuls, 1 byte for drive way

Just finished Z!! :D I made a oldham coupler of MDF (had no other material home hehe) Works fine until i can make something more serious! Made a simple test...

haha very inventive!

hi guys

i can see yall been havin some fun on your bf20's
now i'ld like too ask you if anyone took his millinghead(spindle etc.)
a part yet for what i'ld like to know is :
if a gear/drivebelt modifiation would be able too crank that rpm up a lil like the sieg
were they replace the plastic gears for better quality drivebelts and achieve as well a more silent run as some extra rpm's

and offcourse i'ld like too know if anyone has any ideas how the spindle will react too more speed

thx in advance guys(i'm still hopin i'll be able too convert mine soooon)

Hi Guys , just joined this forum
I have converted a BF20 Vario to 3 axis cnc and seem to have been through most of what you guys are discussing. I have played around with upping the spindle speed as high as 12000rpm. I removed the gears inside and the quill feed mech. I made an additional bearing plate on top and coupled the motor with a poly-v belt. I started with a 1:1 ratio but quickly wanted to get little cutters spinning properly and changed to 3:1. At 8000rpm plus the grease starts to burn and the motor wine. I stripped and cleaned the spindle bearings and added just a light rub of Klueber high speed grease and took the seals off the top bearing. After running in for a few hours the bearings run warm but stable at 12000rpm now. The correct preload is tricky!. The bearings are taper rollers which are not ideal for high speed and should be replaced with a matched pair of angular contact bearings $$$$. The next problem is I have the high speed for engraving and fine work but nothing for normal milling, the electronic speed control eventual blew up trying to hold low rpm. I am in the process of fitting a 3phase 750W motor with inverter control. Time to stop messing around!!
I should have tried the other option of attaching a small belt drive to a MT2 taper and drive a small engraving spindle off the side of the main spindle on an adapter plate.

I have many tips on adapting this machine and advise for anyone willing to try. mostly what not to do! its a great little machine!!

Rob

some pics of my machine, operating but still undergoing developement. I would like to enclose the whole thing to contain the spray and mist. I am drawing plans for a integral stand and enclosure with a removable swarf drawer.

Rob

I saw that optimum sell a high speed spindle "attachment"! Have anyone looked into that?

Are you using the ballscrews? Steppers/Servos? How fast can you run the machine :)

I opted to use servos and have large DC motors +/- 800W with 12mm preloaded ball screws with angular thrust bearings on the ends. Driven by Geckos and Desk CNC controller. I can rapid very fast but limit it to about 3000mm/min. cut speed is limited by spindle rpm but good results up to 1000mm/min. the great thing with Desk CNC is you can tune the Accel curves to your liking, even 'S' curves. The geckos also have decent stable trimming. The ball screws are as big as you can squeeze in and suffer from a bit of torsional wind up but only during heavy cuts. its by no means a hunking metal eating machine but does fine work beautifuly

hi guys


i can get m hands on some preloaded ballscrews
the only thing i'm not quite sure that
they are 16mm diameter 28mm including the nuts
except for the fact that this is overkill is there anyway
that they would be able to fit in the bf20
i'm sure Z-axis shouldn't be a prob

by the way thx Rob van Z

Hi irondigit

the nuts I used were the threaded type (not flange) and were 25mm OD. the Z axis is no problem but the X and Y are a tight fit. I had to mill away small pockets in the Y slide (the one where the nuts attach) to make clearance for them. I also had to mill the bottom of the table to allow the Y nut to clear from limit to limit. the cast iron has a tough skin so dont use anything less than a insert rose cutter to eat it off. I paid dearly for that lesson. I drew up the whole machine in Solid Edge to figure out the adaptions and space. So if anyone wants the drawings just say what format you want dxf, par etc
Alignment of the screws is critical, you need to make sure your adaptions have some adjustment or self alignment capability. the latter is another place for backlash to creep in. If you can squeeze those 16mm screws in you'll have a nice tight machine

Rob

oh and never take the nuts off a preloaded srew assembly!!!

nice rob van Z

only i was wondering :what is insert rose cutter ?

and on what machine did you do the cutting on the y slide ?
not the bf20 itself i suppose ?

thx in advance guys

I guess we all have our own local nick names for tooling, the rose cutter has a number of indexed TC inserts that do the cutting. Kinda looks like a rose if you have that warped sense of seeing beauty in machines. If I really liked a girl I might give her one but only if I could use it!
I milled the castings on a big old Bridgeport

Hey guys is this the same mill as a Vario 20 or is some other variation? http://img200.imageshack.us/img200/6404/precisemill2zg.jpg (http://imageshack.us)

The only difference I see is the z axis handle is on top and the front looks like its missing what your version of the Vario has.

This is a clone of the BF16 Vario.
It's the smaller brother.

http://www.quantum-machines.com/products/drilling-milling-machine/index.html

Hey thanx, yeah I found that out a little while after I made that post. Darn you guys are lucky thats all they really sell over here in America as far as a small mill goes, I really like that BF20 with the larger table. I hope some day they start selling them over here.

hi guys

all yallz bf-20 lookin mighty nice
this thread is gettin a kinda ''pimp my machine'' feel to me

anyway i wanted to ask ya guys if
20oz-in. contineous torque at 170 oz-in. stall torque DC servo motors will hold this machine ??

and except for prize what should a n00b be aware of using servo's instead of steppers ? is there any maintenance of anykind for the se motors or .....

That a little on the light side. I'd go for double that. X and Y are getting 0,28Nm continious and Z is getting 0,6 continious with in X and Y 1:3 reduction and in Z 1:6 reduction due to the large lead I have in my Z-Axis leadscrew.

Price is not a issue.
2Nm holding torque steppers are not any cheaper than a couple of DC motors with optical encoders. Power supply is not any cheaper for the steppers and controllers cost roughly the same too. Try ebay and look for dc-servo or dc motor and see what that stuff costs you. Ecoders are ~E30 each on ebay.de and I saw a great Dunkermotor 80x80 go for ~E60. Thats only E90 for a motor thats allready on the heavy side for the X and Y axis.
Power supply a a big torroid transformer (between 500VA and 1000VA) with a starting current limiter a bridge rectifier and a couple of big capacitors.

My power supply cost me around E100 and is built around 2 Velleman Torroids 500VA with 2x 39V secundary (bought cheap from a store that ordered them for somebody that did not pick it up).
My servo's are Dunkermotor 63x55 40v for x and y and a Dunkermotor 80x80 40v for Z bought together with 3 500cpr encoders and a bucket full of ball bearings and some other motors for E40 at a local junkyard (4x Dunkermotor 63x55, 1x Dunkermotor 80x80 and 1x Dunkermotor 53x58).
I have 2 ball screws 12x4mm in the right lengths for E50 and 1 ball screw 20x20mm for E30,-.

I hope this helps. Try visiting a local metal scrap yard. You'll be amazed at the amount of stuff you can pick up there for a nickle and a dime. Yesterday I bought an enclosure 60x40x30 with a metal door and two locks including a lot of connection material and stuff like that for the grand price of E3,-. This will be my enclosure for the PS, switches for stuff like coolant and my UHU servo controllers (www.uhu-servo.de)

Erik Jan

he Erik Jan

always fast and informative i love this guy

thx for all the info BUT:
with my limited skill i decided to go start with a all in one package from the same place
so í can be sure all is compatible and service right now i was lookin a a system/kit from deskcnc i really like the probe also and as far as i could see on their site they only have servo's
any other remarks and experiences with dealers and their kits are very welcome

Hi Erik Jan,

I took a look at the videos on the uhu-servo site. Very nice. I am interested in the spindle motor being used. Do you have any details, links or references you would be willing to share.

Regards
Phil

What are you referring to. The milling motors or the motors driving the trapezoid / ball screws. You can always try to mail Uli. He's very coorporative and has a lot of knowledge to share.

Erik Jan

@IronDigit
Is DeskCNC a complete package?

If you're looking for a complete package that fits your little baby look at the CNC retrofit by Optimum. They designed an addon package for their mill. DamenCNC is also working on an addon set.

Check the first posts in this thread for more info about the damencnc.
Optimum retrofit set http://www.optimum-maschinen.de/produkte/1/cnc-anbausatz-fraesen/index.html

Erik Jan

The spindle motor driving the cutter.

Phil

What are you referring to. The milling motors or the motors driving the trapezoid / ball screws. You can always try to mail Uli. He's very coorporative and has a lot of knowledge to share.

Erik Jan

he erik jan

i guess deskcnc isn't a complete kit but :
the deskcnc 'cnc system' is
can be expanded up to 6axis coming all in 1 with
deskcnc handling the CAM-part and the controller card doing the motor driving
as many servo's as Axis' ordered in combination with that probe they offer
i think i'll be able to set up something very sweet
All thats missing now is CAD i got trials of bobcad and alibre i m trying to figure out how that worx allthough they seem totally different

and as usual nothing i say here i know 100procent for sure so if i missed something
i'ld be very pleased hearing yall opinions and experiences with deskcnc
especially the probe

Hi,

Can someone repost the files for the digital rpm meter as the ones that are listed are corrupted. Much appreciated.

Sebastian

hi guys

its been a while since any1 posted i hope yall still interested

i've been having some probs with me Z-axis -it won't move up&down as smoothly as it used too instead its putting up one heck of a fight and the funniest thing is : NO VISIBLE DAMAGE i even took the complete Z-axis apart to the last screw except for what seems too e some normal wear&tear on the leadnut and some teeny weeny only visible with a magnifying glass scratches on the leadscrew.

i'ld like too ask you guys did you encounter something like this with your machines ? and how/did you solve it ?

and also after taking the Z-axis apart i couldn't help noticing that for a ANTI-BACKLASH solution you'ld need to replaca more then just the leadscrew for a ballscrew
so i'ld like too know from yall guys that converted or already buying parts for the conversion --what exactly are you replacing except for the leadscrew and handles?
and by the way how did yall guys connect your Z-axis ?by a direct coupling to the screw or did you use the 90degrees gears along with the original handturning wheel ?
and anyother adjustments you've made to the mill

Hi

Ist off I used a timing belt to couple the motor to the ball screw. This takes care of any miss alignment stress on the screw. 2nd, miss alignment of the lead screw will cause it to run tight. The ball nut, screw and thrust bearing must be perfectly alligned to run smooth. And last , you need to replace the thrust bearing with a double row angular contact bearing and make sure that its clamped in place with even pressure on its casing. Its very easy to warp the outer bearing race and cause rough running.
If you like I can send you drawings of all the adaptions ive made and bearing no's etc

Regards

Rob

This is my temporary solution for Z :D I had no materials at home, and wanted Z running to start learning, so i made a Oldham type coupler of MDF! Works great but the stepper is a bit to weak as i have no counterweight :P I get 150mm/minute or so...

hi guys thx for the replies again

first of all i'ld love to see what you did Rob so lets have that drawings until now you've always managed too impress me and i trust there will be no difference this time

and for JBV i'ld recomend you too try coupling your motor directly too the leadscrew on top of the machine and leave the turningwheel on the side for maybe manual operation/setup or whatever cause there is some serious slop in the gears that connect the handturningwheel/mdfcoupler too your leadscrew i dont think you'll ever be able too reduce backlash that way unless your gears are better made and i just happened too get a missfit

cheers guys and thx alot don't forget too chekk out my thread on Z-axis probs

I have perhaps 1 degree of backlash in the gears (0,01 mm on the leadscrew), but i don't think thats a big problem, the weight of the head keep it down :) It's ok for now! When i buy ballscrews i will make a new top plate for the column.

Hello manurc

I find your RPM Counter ! But it does not working correctly.

The Pic Programm was with Options ER Osc. But what is the correct value of the Resistor ? for RA7 ? 4Mhz ?
I dont get the pic working how do i connect the Display ?KS0073 Controller ? On you Display pin 1 and 5 (R/W) is bridged ? Please can you help me to get it working ?

MFG
Burkhardt

hello budybergy
for pic, you must use the internal osc , as there is no Xtal connected

to connect the display, 1 gnd, 2 +5v, 3 contrast adj, 4 gnd, 5 RB3, 6 RB2, 11 ... 14 RB4 ..8

hope it will help you

Manu

hi

Some interesting ideas in this thread , keep up the good work guys

cheers

Hello Manu
now my LCD Display Work very well but you in you Pinlayout you told me there was an failure on the pins. But now it works. Thank you

But 1 little problem i get. Why the RPM Counter counts the double real RPM ?

Maschine has 2000rpm in real you count 2x time and display 4000rpm ?
and the rpm lacks 200rpms slower as real.
Why ? Can i get the source of it ? Perhaps i can fix it?
Or i must do my own programming on this layout.

Thank you Manu
for this little helpfull thing.

Hello Buddybergy

Happy to see that you fixed the RPM gauge

How many "Frame" did you paint on the spindle ?
on mine , i just have 50 % black and 50 % natural iron to reflect the IR signal
so 1 rpm = 1 low (or high) signal

hope it can help you

Manu

Thank you Manu

but i do so 50%/50%. I have a spezial hand rpm meter which told me
the half of it and this is right,True

Your Counter programm counts 2 form black/to white and white to black .

I have try all. 2 Black part doubles the RPM. 25%black/25%white 25%bl 25&w.
or litte reflekt but no other displaying.
Or is it a problem to use a CNY70 ?

Please send me to my private address the last working .asm .hex. Perhaps it is Problem that is where a previos version of you programm ?

I have it from this site. A few pics of my LCD.

MFG
Buddy

hehe,in fact we have been order the BF machines,then we will have conversion and complete CNC of them soonly after factroy delivery to me.
i sent reply of BF CNC reply here long time http://www.cnczone.com/forums/showthread.php?t=23251
but no one interesting it,right now it is become hot,hehehe.
in fact germany converted them many months or years before,very good machines. hope our future conversion kits will be satisfy for everybody.
Syil

I will rebuild Z for belt drive soon, this is what i have in mind:

did any of you had problem fitting ballscrew for the x axis i have checked the space in between the underside of the table and the sadle and i get about an inch of space

we have been order the BF machines,then we will have conversion and complete CNC of them ...
Any idea when SyilAmerica might have them and what the price will be?

EDIT: holy thread restoration batman... it is taking quite a bit of time to get the BF20 CNC (ie. Syil X5) to market...

i dont think the bf20 is the syilx5

edit: from looking at the spec the say i think its the bf20 mine came at around 120kg not 70kg, there are certain thing i dont get in there description of it like

Solid concrete polymer on a steel base, precision guides? mine is cast iron all the way

from looking at the spec the say i think its the bf20 mine came at around 120kg not 70kg, there are certain thing i dont get in there description of it like Solid concrete polymer on a steel base, precision guides? mine is cast iron all the way
I believe that Syil has not actually completed their webpages for their new mills; in many cases they just block copied the info straight across from the X2 or X3 mil, resulting in some obvious mistakes such as the ones you pointed out. I think the steel encased polymer only applies to their new X4/X4+ mill.