Re: [CAD_CAM_EDM_DRO] testing for squareness

Try the following test for out of square (it works for ALL machines):

First place a flat test piece in the vise. (This piece must have surfaces
parallel to each other or the test will be inaccurate.) The test piece
should also be parallel to the table after clamping, therefore clamping the
piece to table would be even better.

Next "paint" an area on the top surface with a black magic marker (DO NOT
use dykem blue or anything that leaves a thick surface on top of the test
piece).

Install an end mill in the spindle.

Lower the cutter 'till it just clears the part.

Turn on the spindle.

Raise the table (or lower the spindle) in VERY SMALL increments (.001 or
less).

If the spindle is square to the table, a full circle will be cut when it
first contacts the "paint". If it does not cut a full circle, one or both
axis is off. If either or both axis are off, a quick examination of the cut
made will indicate not only which axis is off but the direction of cutter
tilt.

Smoke

>
>Responses to the questions from Craig Libuse on the Sherline
>list: "Instructions on squaring up a machine can be found on our web
>site at
>
>www.sherline.com/2000inst.htm.
>
><<I was told one way to test for squareness is to machine a circle.
>If the x and y axes are not 90 degrees to each other, the circle will
>not be a perfect circle.>>
>
>"Keep in mind that when machining a circle with a CNC machine that
>does not have ball lead screws, any backlash in the X and Y will show
>up as an "out of round" condition as backlash is pulled out of the
>leadscrew with a change in direction. This is not a function of it
>being out of square."
>
>
>
>Addresses:
>FAQ: http://www.ktmarketing.com/faq.html
>FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
>
>Post messages: CAD_CAM_EDM_DRO@yahoogroups.com
>Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
>Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
>List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...
>Moderator: jmelson@... timg@... [Moderator]
>URL to this page: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
>bill,
>List Manager
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>