still not progressed much ...

good news is i bought a new stepper motor and managed to connect it so it works (wasn't easy since i didn't have the pinout of the old motor so i had to determine which lead is which first)
bad news is: it wasn't the stepper, still losing steps with the new one

so it's something downstream from the stepper. I doubt it's the cable since it's really well attached and there is no movement of the cable at all when the machine is running since the stepper transmits through a belt. I will try to double check it but it'll be hard since it's channeled through the underside of the machine.

being a musician i'd quite like to try out listening to the signal in audio
i'm not sure i completely understand the instructions.

Quote Originally Posted by probinson View Post
To use headphone to monitor the signals you need to connect a resistor to cut down the signal level. The value of the resistor isn't critical. We just would rather not blow out either the headset or our eardrums.

The headphone plug has 3 contacts:
Tip - Left channel
Ring - Right channel
Sleeve - Common ground for both channels

I find it easiest to wrap one lead of the resistor around the sleeve ground and poke the other lead into the housing, touching one of the pins. Then use the tip like a probe to connect to another pin. With this you will be able to hear if missing step signals are causing the problem.
After that you will at least have some idea where to look.
Pete
poke into which housing ? i have all the leads coming from the driver (4 leads) going into clip connectors so it's easy to connect .. but not completely sure what to connect to what ...

in any case ... since the problem seems to be in the old electronics of the machine i think i will stop troubleshooting this at this point and completely eliminate the old electronics and power stage. i'll probably buy 3 new power stages from Leadshine, a good power supply and if i have to an interfaceboard but i have this super cheap chinese 6-axis USB board lying around which i'll try first.

thx everyone for your help with this .. i'll keep you posted when the new electronics are up