Re: [CAD_CAM_EDM_DRO] Re: Z-axis CNC conversion on a mill-drill: a challenge (long)

No I never did make up a set of plans but I think I have the motors mounts in my cad files.
In this months issue of HSM Roland Friestad has a good article on retrofitting a mill drill and has drawings for the XY ballscrew drive nuts and the ballscrew end pieces.

On my mill drill, in addition to the quill modification, I did a couple of novel things to make the ballscrews zero backlash.
I made a new drive nut that was tapped for the 15/16-16 threads. I installed the ballscrew and one of the ballnuts and tighten it on one side of the drive. Then I took another ballnut without and balls in it. And screwed it in nearly all the way. Then I proceeded to load the balls. Once all the ball were loaded I then turned the ballnut to preload the ballscrew with the zero backlash. Then I tighten a set screw locking it in place. It been running for about 5 y ears now with no problem.
On the Y axis I again made a new Y axis drive nut block and tapped it 15/16-16. This time I installed one ballnut with the theads facing the drive nut block. I then install a second ballbut with the threads away from the first one. Thus the backs of the ballnuts were back to back. I adjusted the backlash by turning the second one until I had a preload on it. Then I tack welded it in two places using my Mig welder.
Now that I think about it I have some pictures of this somewhere. If interested I can email them to you.
Yes I mentioned before that after the new pinion shaft was installed and the eccentric bushing were rotated and then locked inplace that I had to elongage the holes about 1/32" on the worm wheel housing to reduce the worm to worm wheel backlash.

Dan Mauch
economical 3D scanner software and kits
low cost stepper and servo motors.
cases for Gecko drives
kits and assembled 3-4 axis drives
www.camtronics-cnc.com
www.seanet.com/~dmauch

----- Original Message -----
From: arquibaldo2001
To: CAD_CAM_EDM_DRO@yahoogroups.com
Sent: Saturday, April 28, 2007 7:36 PM
Subject: [CAD_CAM_EDM_DRO] Re: Z-axis CNC conversion on a mill-drill: a challenge (long)


Impressive video, Dan Mauch. Thank you. I deeply envy your Mill-Drill.

Now, if you please, I must ask:

-Have you published and/or would you sell plans/photos/drawings
detailling your CNC conversion?

-What about the X&Y axis? Did you convert to ballscrew/balnut or
are you using the original Acme screw&nut?

-On the Z axis, you already explained the rack-pinion modification.
But what about the pinion-worm_shaft link? Is it the original?
Didn't it add its own backlash?

Sorry to bother you, but I am very interested in doing to my machine
something similar to what you have accomplished.

Nelson





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