Messages

11

General Mach Discussion / Re: Some starting advice for two steppers on one axis

« on: February 29, 2016, 07:37:34 PM »

It worked,, !! thanks ger21 !!!

12

General Mach Discussion / Re: Some starting advice for two steppers on one axis

« on: February 29, 2016, 07:36:56 PM »

Ok,  giving it a shot.  A crude sketch of what I'm going to do.

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General Mach Discussion / Re: Some starting advice for two steppers on one axis

« on: February 29, 2016, 07:05:01 PM »

I don't subscribe to an online pic posting site so I can't provide a sketch of the basic layout.  Does this site not let you post a pic from your local PC??

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General Mach Discussion / Re: Some starting advice for two steppers on one axis

« on: February 29, 2016, 06:43:58 PM »

Positioning accuracy needs to be .002-.005in.
I cannot have sag along the Z axis, so I thought the best approach is to tie the Z axis bar on both ends for proper support.
I don't have much room for a driveshaft along the tube axis to drive the other end.

This is not the typical use of CNC for metal or wood working, but I proposed this idea as an acceptable positioning device to map the magnet bore tube since I have some experience with a HobbyCNC controller with my lathe in my home shop.

Any other ideas?

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General Mach Discussion / Re: Some starting advice for two steppers on one axis

« on: February 28, 2016, 04:17:35 PM »

Just thought up another squaring option that might work well.
If one was to put a simple SPST toggle switch on the PULSE line to one of the paired drives, isolate the signal to that drive while squaring with the other, then close the switch for normal operation.
A viable work around ?

Just thinkin",
Russ

This is an interesting idea..  I was thinking I would do this mechanically, but isolating them temporarily to adjust with Mach seems like a good idea.  As long as they would not jump when reenergized.

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General Mach Discussion / Re: Some starting advice for two steppers on one axis

« on: February 28, 2016, 04:09:45 PM »

Yes, squaring will be needed.  The two xy tables will be carrying a single bar of some sort for the hall probe along a Z axis.

Picture a 12 in DIA tube, 6 ft. long with an X-Y table at each end that will position a bar in the tube.  A probe runs along the bar (Z axis)
to scan the inside of the tube, thus mapping the magnetic field.  Positioning on X, Y, and Z.

17

General Mach Discussion / Re: Some starting advice for two steppers on one axis

« on: February 26, 2016, 07:51:45 PM »

AAAHH,,, I see.  Well that sounds like a champ!  I'll do some more research.  I did find a review topic on here for the UC300, and folks have good things to say.
I will look into it further and I'm sure I'll have more questions.  Thanks so much!

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General Mach Discussion / Re: Some starting advice for two steppers on one axis

« on: February 26, 2016, 07:02:39 PM »

Oh,, wait,,, this board would be another option and would take the place of a gecko G540 or hobby CNC board...  Skimming the manual, it seems like a nice option, and gives me the number of axis I need.  Interesting.

BTW, for those who might be interested.
This project is to build a CNC controlled magnetic field mapping probe.  It will map the magnetic field of superconducting magnets used in the FRIB beam line upgrade at MSU in Lansing Mi.
http://www.frib.msu.edu

19

General Mach Discussion / Re: Some starting advice for two steppers on one axis

« on: February 26, 2016, 06:43:57 PM »

I see,,

http://cncdrive.com/UC300.html

This looks to be the best option.

Thanks and learning a lot about a good launching point for this project.  I might have some connectivity questions, but I'll do some research first.

20

General Mach Discussion / Re: Some starting advice for two steppers on one axis

« on: February 26, 2016, 06:23:58 PM »

Opps, I meant PCI,, good lord.. haha

You mean something like this?
http://www.pmdx.com/2PARPCI