stepper motors glitching

[routercnc]

Hi Lee,

I did some more testing last night, and got the PC spec.

Processor AMD Athlon XP 2600
RAM 1.5Gb
Graphics card FX5200 128MB ram (i.e. not built-in)
MB Asus A7N8X Deluxe Gold
Windows XP SP3

A few years old, but plenty good enough!

Checked the output of the Parallel port directly and still got glitches on the scope.

Then disabled the PCI parallel port and got clean pulses from the main port! Quickly hooked up the steppers and got clean runs - for about 20 seconds, then the glitches came back. The allegro chips all got quite warm on the drivers, even though the current is limited to 1A. System3 is an all in one board, and for these tests it is out in the open. Shouldn't be overheating surely? Thinking about heatsinks and direct fans on chips to see if this helps (case has general exit fan).

I might need to remove AVG to see if that helps, but the chip heating needs to be checked out a bit more first.

Thanks
Barry