RE: [CAD_CAM_EDM_DRO] Z-Axis backlash removal

Thanks Dan.

The mill drill is, like most of them, pretty similar to the Grizzly G1005.
Although it's been branded with a local distributors name. The details on
the CNC conversion from HSM January 2002 seems to match it pretty well.

I'd be interested in receiving the details on the bearings or anything else
you have as a solution. I'll send you my email address separately.

I'll have to take it apart to see what you are talking about
with the Quill cross shaft and pinion but I can envision what you are
saying.



Thanks



Dave Sage



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From: CAD_CAM_EDM_DRO@yahoogroups.com
[mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of Dan Mauch
Sent: Wednesday, June 04, 2008 2:05 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: Re: [CAD_CAM_EDM_DRO] Z-Axis backlash removal



Your post doesn't say what size your mill drill is or what model.
Most mill drills seem to come stock with .020" backlash. Most of the problem
is due to the machining of the bores for the cross shaft and pinion. They
machine the bore so that the pinion is loose against the rack on the quill.
The other problem is the worn wheel housing is properly adjusted so that the
worm contacts the worm wheel properly.
There are a couple solutions.
One is to counterbalance the quill so that the backlash is always up. The
other method is to replace the existing cross shaft flanged bearing with a
new one that is made excentric. This would also require the machining of the
shaft on the worm wheel side so that there are two eccentric bearings
holding the cross shaft. These are then roated until the backlash is gone.
If you want I have a detailed explaination of this procedure. Give me your
email address and I'll send it to you am also woking on an air spring that
has a constant 40 lb lift of the quill. I have one in my mill drill but I
haven't had time to to much testing
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: Dave Sage
To: CAD_CAM_EDM_ <mailto:CAD_CAM_EDM_DRO%40yahoogroups.com>
DRO@yahoogroups.com
Sent: Tuesday, June 03, 2008 5:04 PM
Subject: [CAD_CAM_EDM_DRO] Z-Axis backlash removal

Hi:

This is my first post here. I've been sitting in the bushes trying to gather
as much info as possible.

I'm in the process of converting my mill/drill to CNC. I have ball screws
ordered for the X and Y and motors and drives ready to go for all 3 axis.
I'm wondering what to do to remove the backlash (about 15thou) from the
Z-axis. If anyone has any suggestions what is typically done I'd appreciate
it and I'd follow that lead.

Sage

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