Re: Loosing position and need help...

Right idea wrong coefficents. Aluminum expands or contracts at a rate
od .0000129 Inches per inch per degree F, steel at .0000065 Inches per
inch per degree F. Or Aluminum changes at almost 200% the rate of steel.

gary

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Randy Wink" <rwwink@i...> wrote:
>
> Would sound like you getting some growth. Heat causes aluminum to
grow at a
> rate of .0000063 inch per inch per degree F and steel will grow at
about 1/3
> of that amount. You could also get some variation in readings based
on the
> temperature in the electronics cabinet..causing resistors to change
values
> and such.
> R. Wink
>
> > -----Original Message-----
> > From: mmurray701 [mailto:gmurray@n...]
> > Sent: Sunday, January 02, 2005 12:00 AM
> > To: CAD_CAM_EDM_DRO@yahoogroups.com
> > Subject: [CAD_CAM_EDM_DRO] Loosing position and need help...
> >
> >
> >
> >
> > I have a Taig CNC mill powered by G320's, Electrocraft E543 servos
> > with renco encoders setup in a 2:1 reduction. Running off a P133 in
> > dos with TurboCNC V3 (not sure exactly what version but its the
> > latest release of V3)
> >
> > I'm picking up a few thousandths on long machining files. If I run
> > an hour long program i could be off by a few thousanths on X or Y,
> > seems to vary depending on what file i'm running. I've written all
> > sorts of test files and can never seem to duplicate the problem.
> >
> > I have no idea whats causing it, tried almost everything to fix it
> > with no luck and its really starting to turn me off from CNC
> > machining. I thought I knew enough about this to solve it but no
> > luck. Have to turn to the experts on here for help.
> >
> > The fault lights are not comming on, I've tried a different
> > computer, and shielded cables are used everywhere so picking up
> > steps is unlikely. Anybody have any suggestions on something else to
> > try? When I did switch computers, i did keep the same hard drive,
> > should i format it and start fresh? Anything else?
> >
> >
> >
> >
> >
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