Hi - this is my first post on this forum. I have converted a SIEG X2 milling machine to CNC and I am using Mach 3 on a decent PC (3GHz 1G ram etc). I am having the same problem as Monte - you sit the motor on the desk and just run it and you can hear it jolting a bit with a fairly repeatable pattern. Seeing his video on YouTube makes me convinced its almost an identical problem to mine.
Luckily I am an electronic engineer so I have looked at the step signals on a scope. The steps were all over the place - i.e. the signals generated by Mach 3 were not evenly spaced but had a *huge* jitter - for example sometimes gaps of a few times the correct spacing, sometime very little time between. Clearly this problem is coming from the software side of things. My guess is some process on the computer taking a higher priority and screwing things up. Anyway I read the text file on the Mach 3 website saying things you can do to improve the performance and I ran the .bat file it mentioned (I think it changes the timing method or something), which improved things. Now, I get regular spacing, and I do get jitter, but it is regular - i.e. its either a certain amount too long or a certain amount too short. There is clearly still something interrupting the low level thread. I cannot figure out what it is, but my bets are on something like the wireless device on the computer (although I have tried disabling it).
Any suggestions would be much appreciated.
On a different issue - on my SIEG X2 there is a thrust bearing on at the opposite end of the x axis to the motor, which was the original bearing, and its not running smooth at all. Does anyone know where I can get a better bearing for this? The original is just a couple of cups and a ball race, not a sealed unit.
Cheers,
Reuben