Help with Sherline Mill Retrofit from Backtrack

[Reax]

I am new to CNC and this forum so please be gentle with me
I recently purchased a used Sherline 5400 that is 3 axis CNC
the books were lost in transit and all I can find out about this is that it is
a retrofit from Backtrack Manufacturing which is written on the driver board
I was told that this system is about 5-6 years old, looks older to me but then I am new.
The mill has the old style backlash nut locks. My question really has to do with the steppers, all that is on them is "57BYG" and "No.960710"
no voltage or amps, I think the driver maybe dead and would like to replace it
but with out the volts and or amps of the motors I don't know what to buy.
Does anyone know this system and could you supply me any info at all.
I would sure appreciate it! My budget is of course low and would hate to have to buy motors as well,
maybe later after I become more experienced it would pay but right now I just what to learn how to do this all
TIA.

[awerby]

but they might work. Here's a datasheet for that type of motor, but it's not too specific - apparently that's a type rather than a specific motor.

http://www.globalspec.com/datasheets...E-4705F5793C78

You should be able to run it with the standard Sherline driver: part #8760 ($600) - if it still doesn't work well, you can order their official steppers. Alternatively, you can get a Gecko G-540 drive, a 50v power supply, and Mach3.

Andrew Werby
www.computersculpture.com

[jkcab]

Reax,
If you go to ebay and search for EZCNC you will find a guy selling 2 boards he has left in stock for $60.00 ea. These are 4 axis boards with allegro chips. They work with 12-34vdc and 2.5 amp. I cant imagine any company doing a refit without using at least 24 volts. Judging by the size I would say they are low amp motors and doubt they will need to draw more than 2.5. If you use the board I suggest and a 24vdc power supply a little wiring and Mach 3 you should be up and running for less than $100.00. There are a few on ebay that sell the whole shootin match for 3 axis (different board w/ motors and ps) for about $170.00? Just remember once every thing is hooked up you still need an enclosure for the electronics and incidentals $$ included in your budget. It adds up fast!!
Jeff

[vlmarshall]

Congrats on the mill... I've got an older Sherline as well, and other than the underpowered Xylotex driver I put on it, it's been a great little machine for years.

Just remember once every thing is hooked up you still need an enclosure for the electronics...

You could go with the super-cheap enclosure I used to contain my lathe's Gecko drives and power supply... a plastic tub: Yet another Sherline lathe thread


Certainly not the fanciest setup, but it was fast and easy, and I had jobs waiting for the lathe to be finished.

[Reax]

I just got those last two boards, Thanks Jeff for the heads up
I saved so much money that
I am now going to build my asian 7x12 lathe into a cnc machine as well
in addition to the 2 boards at half price I just got 2 "Power One power supply 24 VDC 10.5A PFC250-1024F" power supplies on ebay for 10 bucks each and with the cheap enclosers vlmarshall suggested I am set
THANKS AGAIN. This is what these forums are for helping each other !!!!

sure am glad I kept all my old computer stuff

[jkcab]

I had forgotten I'd seen that enclosure! That was a good Idea just be sure to watch your grounds. Harbor freight sells a rubber grommet kit for cheep.
I actually striped the braded sheath out of some coax cable for shelding.
By the way you didn't have to be so greedy. I was thinking of buying one of those since I only have a three axis board!!
Any way you might not want to get too ahead of yourself. When calculating for motor voltage you should multipy the square root of the mH of the motor by 32 to get the proper voltage. Most systems are far under rated. If you buy a 6 wire unipolar motor ( most common ) and wire it bipolar you have to quadruple the mH prior to aplying the above formula. Those boards have a limit of 32 vdc and you will probably need every bit of that for a 7x10.
The good news is the bipolar wiring will half the amp requirement. It seems the limiting factor is voltage. Again the good news is the voltage is needed for high speeds not torque. They might be a little light for a large enough motor for the 7x10? Reax good luck, glad to have helped and let us know how you make out.
On another note I have a question for Vmarshal. How do you find your mill for repetable acuracy? I am hoping to use mine for milling some very small plastic injection molds. My mill is an old spectralight sherline (similar set up to yours). I was thinking of doing the bearing mod you did and adding the Z axis backlash system from Sherline. My 90vdc motor already runs at 10,000 rpms so I think I'm going to have to make my own 1:1 pullys because Sherlines kit is for a 6000rpm motor.
I built an automatic draw bar that actuates two fingers for a pullstud on some custom made er 16 taper tool holders. The system works great and I'm programing to make the parts for an auto tool changer to mate with the numatic drawbar system.
Jeff

[Reax]

I bought a Mechatronics 4 axis board from ebay and I need a little help if possible please.
I cannot get any axis to run a motor except the "X" axis, I get power lights and fuses are good on the
other axis but no motor movement, I am able to set REF voltage for AMPS and PFD on all axis.
Is there something I need to be doing on limit switches to get "Y Z A" axis to run a motor?
I read the manual and followed all the set up and the "X axis" runs fine, micro stepping even works good, using Quickstep to test.
The manual says there is a way to enable/disable each axis via the opto coupler but I am thinking this is for limit switch use and the board should come with all axis enabled by default ?

[jkcab]

Reax,
If you have the X axis working then try hooking the Y and Z motor to the X axis. Make sure you turn the power OFF BEFORE you unplug or plug in a motor!! If the other two axis work when hooked to the X then you need to go back and ohm out your wiring to make sure every thing is correct. What controll software are you using? If it is Mach 3 then you need to check the Sherline box when using the Mechtronics board. Remember when ever you troubleshoot any system only change one variable at a time.
Jeff