Thanks for the interest Mike - I haven't had a whole lot of time to spend on it - have to make those widgets, and I have a workaround. Here's what I have done:
I ran a program peck drilling 80 holes, with 10 pecks per hole, and touched off on an indicator before and after to see if it's losing position, and it was roughly .0006" off (from memory) - considering my quick set up, that the tool's not flat and the machine was made 20 years ago, I consider that to be no error. A friend of mine who is a lot more knowledgeable than me ( that's most people ) said "We should probably stop calling our term "bounce" and call it servo following error on rapid moves...as I understand it all machines have this, and that is why a programmer never rapids right to the start of cutting, or even .010" close!". He also told me on the phone that Mach 3 has a closed loop feedback with the galil motion control card I have so it knows in real time what the encoder shows, so indeed, it can overrun its mark, and then correct without losing position, unlike most other systems ( hope I got that right ).
Anyway, I think that motor tuning can cure it, but since it doesn't lose position it would mean that my rapid would be slower for everything else, and I don't do that much peck drilling, so I've been reluctant to slow it down. I probably shouldn't worry about speed - I do short runs, so the difference would be negligible, and if it keeps me from chipping a tool down the road, it would time ( and $$) saved.
Alex