Hi
I can control my CNC Mill using Mach3 but have skipping steps and speed changes on all axis motors at random times and places.

I have:
Windows7 32bit
parallel port on motherboard, set to EPP
parallel optical breakout board
3x 2M542-N Stepper Drivers
3x Nema 23 Motors

I have already proved there is no wiring problems or noise(see below), and the problem happens even when the motors are disconnected from the CNC machine so it cant be missalignment of the machine or rough spots etc.

I made a little circuit using NE555 timer to control the motors via the 2M542-N motor drivers, bypassing the PC. There was no skipping steps or speed issues at all.
Therefore I can only assume the problem is somewhere at the PC end.

Help please!!! I am so close to getting my machine working and just cant fix this issue!!!

Andy

try another pc

Hi
I would have tried this if I had one!
As buying a new one is a fair amount of money and is not guaranteed to solve my problem, I wanted to try and diagnose the problem fully before doing so.
Thanks for your reply

do you have a friend that would let you try their computer, all you need to do is load mach3 and copy the xml over.

Have you run the DriverTest.exe found in the /mach3 folder?
If so, what were the results?

John

I have just run it, does it save a file somewhere?

My PC and my friends are all 64bit and have no parallel unfortunately!

OK so realised I was running an old version of mach3.
installed newest version and ran driver test.
the display showed excellent, then every now and then pulsing too fast.
the display of the pulse can be a bit sketchy at times. I will try for a screenshot and upload
Andy

Hopefully attached...

I´m with the same problem... the glitches that your pictures shows in DriverTest are present in mine too.

Hopefully attached...