re:RE: Home built machine setup, perpendicularity

Another note:
Your ways should be straight as well as perpendicular.
The same mill & flip technique can be used to detect non-straightness in a
linear travel.

By milling two adjacent edges, you've made an "L" square.

Note that if the ways aren't straight, then when you flip the L square over
the y edge will be at the other end of the x travel. If the x axis isn't
straight, you won't be measuring perpendicularity along!

OTOH, if you mill a T square, and the edge doesn't translate when you flip
it over, then this can be avoided.

Straightness first, then perpendicularity.

regards-
Elliot

Date: Tue, 12 Jul 2005 07:50:12 -0700
From: Drew Rogge <drew@...>
Subject: RE: Home built machine setup, perpendicularity


Hi Scott,

I was thinking about this last night and if you can do the final
adjustment for perpendicularity after you've mounted a spindle I
think I have a way for you to zero in your machine.

The idea is to use the machine to mill two adjacent sides of say
a 1/4" thick 2' square aluminum plate. Then flip the plate over,
front for back, about X axis and indicate the milled edge parallel
with the X axis. If you then use the Y axis to run an indicator
along the other milled edge, the total reading you get will be
twice the error in perpendicularity. Adjust the Y axis until you
get a total indicator reading of half the original reading and
the Y should be at 90 degrees to the X. I would then mill the
edges again and repeat the test to check the results. If there's
still a bit of error you can repeat the adjustment until you're
satisfied with the results.

Hope this is clear enough.

Drew


--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.323 / Virus Database: 267.8.14/48 - Release Date: 7/13/2005