Quote Originally Posted by Davidh
What OS are you running ? WinXP
Have you run the mach 3 optimisation ?.. i.e. switching off unused system processes. don't know. Will investagate.
Have you run the mach 3 pulse rate test on your machine ? No. will investagate
What IS your mach pulse rate on diagnostic page.. does this match set pulse rate ? Dont know
Have you run motor tuning ? No
Are you sure your axis calculations (steps per unit) for mach 3 are correct and that settings are correctly applied. Dont know, didnt calculate but reverse engineered off a ruler.
Are all motors\settings the same ?Y
The problem is almost certainly with your motor setup in mach 3... the responses given to the above questions put it practically beyond all doubt. There may also be a prob with OS.. depending on which\number of processes running in the OS.

Firstly Win XP requires optimisation to run Mach software at it's best. there's a document called optimisation.txt available from arcsoft. It explains the processes which are to be disabled.
You haven't run the mach 3 machine test anyway.. to determine if the software will be stable and able to output a constant pulse.. run the ocxtest.exe in the mach dir.. this usually runs on install unless you cancel it.

Mach pulse rate has nothing to do with your problem.. unless the OS is making it misbehave on it's way to the printer port. I imagine its at the default anyway as you would need to change it to get it otherwise. You need to run axis calculations or your positioning is not accurate.. simple as that... is not a hard calculation and is an example for direct drive connections in the mach manual... you only have to be 1 or 2 step per rev out in your calculations for the positioning to go adrift.

Your main problem stalling\lockup is related to the fact that you haven't run motor tuning... so it looks like the y axis is hitting a speed where it will bind when the other axes are also running.. you have to adjust and save the motor speed\acceleration to a point where when Mach runs it "flat out" you still get smooth motion... from your description I'd suggest adjusting the accelaration setting on the Y axis... stall on direction change is most likely to be acceleration more than speed. this is what motor tuning in mach software is for. to set the performance range for each axis... such that no axis will lock up either on it's own or when in combined motion. The Mach manual is clear enough on this too... This combined with questionable steps per unit setting would give problem cutting arcs and circles.

RTFM bro... that's what it's there for.....