Compumotor S57-102-MO steps/rev?

[wireb]

Trying to set up my Zeta drive with some Compumotor S57-102-MO and found all the appropriate settings and info BUT the steps/rev....

Anyone out there happen to know how many steps/rev these motor are?

Here are the links I have already checked and don't have that information (unless I am just blind and missed it)
http://www.compumotor.com/catalog/c67_74.pdf
http://www.compumotor.com/manuals/s-sx/s/S_chp4_h.pdf


Thanks,
Wire

[epineh]

From your datasheet :

Motors
Type 2-phase hybrid permanent magnet, 1.8 degree

so if you divide 360 by 1.8 ;you get 200 steps per rev.

This would be without microstepping.

Cheers.

Russell.

[wireb]

Yep looks like I was just blind

Currently my controllers (Zeta) are set up for 25000 steps (way overkill as set by the factory)
My current ball screws give me 0.02" per rev. So at 200 steps per rev I should have a minimum step size of 0.0001".

The next 2 lowest options are 400 (0.00005") or 1000 (0.00002"). Has anyone had experience with micro stepping these motors or micro stepping on a mill in general? If your micro stepping can you still lock and hold the motor at any step (long as your under the torque rating)?

This is going on a 4 axis 8"x18"x8" envelope mill. The main use will be engraving and cutting / drilling circuit boards.

Thanks again.

[vger]

Your ballscrews are 50 turns per inch? You will have a bit lower torque with microstepping. I have 4 compumotor drives that are also set for 25000 steps/rev and can't be changed easily. Thinking of using them with some 1 inch pitch screws I have, but that would still be 0.00004" steps. They run REALLY smooth, but slow.

[wireb]

Yep far as I can tell they are all 50 turns per inch. Unfortunately I can't find any specs on these cross slide tables. My long axis is definitely a recirculating ball screw. The smaller axis are some sort of adjustable plastic nut on a acme thread.

Set up a dial indicator and rotated the shaft 360 gave me ~0.02" Also since all the other hardware and dimensions are English/even inch I think this is correct.

Here are some photos of the small axis lead screws
http://img704.imageshack.us/img704/2...00001cm.th.jpg
http://img801.imageshack.us/img801/9...c00003a.th.jpg

[vger]

Wire,

As to the microstepping/holding question... Yes it will hold on a microstep, just not quit as tightly, but almost. Those are really nice slides! Should be perfect for doing PC boards. Cutting PC boards (glass/epoxy) will be very hard on the tooling used for the cut. The glass eats up SiC bits.

My first little CNC was a 5" X 7" X 2" sliding table unit. I used 1/2 10 acme with delrin nuts and it was plenty accurate for doing PC boards.

Enjoy the build.

Steve

[wireb]

Yep been drawing parts in sketch-up like a mad man. Got the slides and motors drawn. and stacked the X on the Y.

But now have to pick out a spindle motor to get my spacing set up to the Z.

Going to stop out at Harbor freight and look at the long neck 25k rpm die grinder.

Any opinions / suggestions on spindle motors?
Main use is going to be PCB and engraving plastic/alu/brass
Also going to do some light 3d milling (rc plane parts max Alu min balsa)

[vger]

Wire,

I just used a varriable speed Dremmel. I pulled the collar off on the spindle end and made an aluminum block that was threaded the same as the collar was for mounting. I turned that aluminum block so it was the same diameter as the Dremmel housing and made 2 clamps (double C block) to mount it to my Z slide.

I found I could leave copper traces that were 0.02 wide using a self made engraving bit.

Steve