RE: [CAD_CAM_EDM_DRO] Re: Any simple way to map ballscrews?

Dave,
Yes, I still have that on the engineering site shown below.
The parallel runner in my case only had to be rough sawn to the
proper cam profile, as .001" compensation equaled about 0.2 inches
on it.

I use emc, and it has screw comp...but in this case I needed to match
two tandem screws.

I used gage blocks to measure screw error. The longest one was one
foot, which was actually a $30 micrometer test mandrel. If you have one
you can easily make duplicates.

The system has worked well for years in a production environment.
BTW I didn't invent it either....the method has been used since the
1820s or so.

Les

Leslie M.Watts
L M Watts Furniture
Tiger Georgia
(706) 212-0242

Main page:
http://www.lmwatts.com
Engineering:
http://www.lmwatts.com/shop.html
Cnc surplus for sale:
http://www.lmwatts.com/forsale.html
Carved signs:
http://www.lmwatts.com/signwp.html

-----Original Message-----
From: CAD_CAM_EDM_DRO@yahoogroups.com
[mailto:CAD_CAM_EDM_DRO@yahoogroups.com]On Behalf Of turbulatordude
Sent: Monday, July 31, 2006 10:59 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Re: Any simple way to map ballscrews?


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "vrsculptor" <vrsculptor@...>

have an arm extend from the nut to a parallel runner. moving that arm
up or down would alter the locaton of the table as a super fine
adjustment. then all you need to do is grind the surface of that
runner so the arm rides on it, compensating as it goes.

I wish I could claim the idea as origional, but Les Watts did that and
had (has?) pictures on his web site.

Assuming a large screw, and a pitch of 1/2" inch, one revolution would
be 0.5" a quarter rev would be 0.125", and an eight rev would be
0.0625" it would be within the rhealm of possibility to correct for
that much over the whole of the axis.

Dave