I have finally worked out most of the bugs in my v90 mill.  I can get my rapids without binding and all seems to be running well.  Until about 45min to 1 hr in on a carving file  the machining will shift over anywhere from .25 to .5 but not miss a lick, the finished part just looks as if it was just shifted over part way through the cutting. Z depth seems OK, just in the x and or y. I have run the same file 7 to 8 times and at different feeds and velocity settings. It does not happen in the same place it is different everytime so I'm sure that it is not the code.  I am thinking that somehow Mach just hickups part way through. I am using CV mode and the part is coming out very good except for the shifting.  I am thinking of buying a smooth stepper hoping that it will fix this glitch.
  Does anyone have any ideas on what could be going on, and what I might try to fix this? I am running mach from my laptop but have also tried a desktop PC and the same thing happens.

Thanks,
Tom

Have you tried optomising per the optomization sheet in the downloads section? If it isn't happening in the same spot may be another application running in the back ground. Also, try de-tuning your motors by 50% in accel and vel. just as a test and lets see if it is skipping steps. Notice if it still jumps and/or by the same amount.

Brett

Yes, I have optimized the system.  I have tried detuning to lower rates, but I will give it another shot tomorrow.

Thanks,
Tom

No problem Tom, let us know how it does.

Brett

This sounds like a problem I had a few years back, dont think I ever found what the problem was, it just started working again properly if I remember correctly, heres a pic of what was happening. If its similar I will have a look back and see what I did (if anything ) to cure it.
Hood

Here is another pic showing where the error actually occurred, as you can see it is the Y axis that stalls only and causes the whole thing to be out. Looked back to see if I found the cure but seems I just tried reinstalling Mach and it cured itself.
Hood

Yes, that is about the same thing that my mach setup is doing. If you can remember what you did to fix it that would be great. The only difference is this mine does not go back in line and continue, it continues in the offset position.

Thanks,
Tom

Well really there was no definite answer to why it happened, I looked back and it just came right after a lot of messing around, think what it probably was, was a corrupt install of Mach, I re downloaded Mach and installed it over the top of itself and I think that cured it.
Hood