Re: [CAD_CAM_EDM_DRO] Loosing position and need help...

////A few thou on a mill is really not that big of a deal although, it still should not be happening. How are you generating code? Is it absolute or incremental? Always program in absolute, it's much easier to keep up with zero's. Sounds like its in the programming. If it were always one axis, I'd be looking at crosstalk issues or a bad encoder. Still may be encoders especially if you are using an auxillary power supply. The USdigital encoders are a good match for Geckos, powered right off the drive. If the power supply can deliver the current (try adjusting accelleration and velocity to a lower setting), the encoders are accurate and there arent any crosstalk interference issues it should never lose position. The PC hard drive would be a very unlikely candidate. And it may just be software? If you use note pad for programs, write a small or use a small program that does not display end cycle position errors then copy and paste the X,Y and Z moves several times to make a program
several minutes long. If there are no errors then I'd be looking for some new CAM software. I use Mach2 for control and mine never loses position. Find a 1 ghz. or better laptop and try a different control software. Ultimately, a servo system should never lose position.

Ron

mmurray701 <gmurray@...> wrote:


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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