Losing steps/position, again

[ngwagwa]

If these are wired in a unipolar manner - which is sounds as though they are... you will need to isolate the centre taps. I appreciate the buggeration that comes with this - and recognise that at this time you're probably trying to keep the machine in a recoverable format (normally I'd just cut/isolate the cable at the stepper), but I understand you may want to be a bit more circumspect. the centre tap will be either to ground or to +V and it'll be causing problems for the driver - certainly your described behaviour I can imagine with the centre taps connected.

So just to recap the X Axis stepper now uses the 2 pairs of wires that have the highest resistance.

Today I thought while I would do the same with the other two steppers starting with the Y axis. Disconnected the 4 leads from the driver and the resistance on each pair is 2.4 ohm. Opened up the cover at the stepper end and to my surprise there were 6 wires connected (X Axis only had 4) I measured the resitance to find the correct two pairs to use and am now lost. Two pairs (brown/orange and red/yellow) have a resistance of 1.8 ohm and the two purple have a resistance of 0.4. I should say at this point the manufacturer of the stepper is unknown. I don't yet know where the purple wires go but all the unused wires that go to the control cabinet from the umbilical have been disconnected and isolated (at least I thought they had). I will trace the 2 purple wires tomorrow or Saturday.

[Doddy]

So just to recap the X Axis stepper now uses the 2 pairs of wires that have the highest resistance.

Today I thought while I would do the same with the other two steppers starting with the Y axis. Disconnected the 4 leads from the driver and the resistance on each pair is 2.4 ohm. Opened up the cover at the stepper end and to my surprise there were 6 wires connected (X Axis only had 4) I measured the resitance to find the correct two pairs to use and am now lost. Two pairs (brown/orange and red/yellow) have a resistance of 1.8 ohm and the two purple have a resistance of 0.4. I should say at this point the manufacturer of the stepper is unknown. I don't yet know where the purple wires go but all the unused wires that go to the control cabinet from the umbilical have been disconnected and isolated (at least I thought they had). I will trace the 2 purple wires tomorrow or Saturday.

...Are you not just measuring the loom resistance in series with the coil resistance?, or have I misunderstood?

[ngwagwa]

...Are you not just measuring the loom resistance in series with the coil resistance?, or have I misunderstood?

The 2 readings of 2.4 were pairs from the stepper disconnected from everything else. The 0.4 on the purples I am not sure now as I only disconnected 1 of them so I knew which was which - I will double check the purples and try and trace then tomorrow providing UPS deliver in the morning otherwise it will be Saturday.

[ngwagwa]

The 2 readings of 2.4 were pairs from the stepper disconnected from everything else. The 0.4 on the purples I am not sure now as I only disconnected 1 of them so I knew which was which - I will double check the purples and try and trace then tomorrow providing UPS deliver in the morning otherwise it will be Saturday.

So out of stepper I have 6 wires 2 pairs each with a resistance of 2.4 and two purple wires with a resistance 0.4. The 2 pairs are connected to the drivers and i have (so far) been unable to trace the purple inside the cabinet but they are not connected together and there is no connection between the 2 puple and the other 2 pairs.

[dazp1976]

So out of stepper I have 6 wires 2 pairs each with a resistance of 2.4 and two purple wires with a resistance 0.4. The 2 pairs are connected to the drivers and i have (so far) been unable to trace the purple inside the cabinet but they are not connected together and there is no connection between the 2 puple and the other 2 pairs.

I've tried reading around while I'm bored and didn't get very far. All I've got is:
6 wire steppers can be wired Unipolar or Bipolar(series).
My guess is it's in series and NC means not connected?

[ngwagwa]

I've tried reading around while I'm bored and didn't get very far. All I've got is:
6 wire steppers can be wired Unipolar or Bipolar(series).
My guess is it's in series and NC means not connected?

That's the configuration on my X Axis (I found out thanks to JAZZNC and Doddy) it was originally wired A+ to COM and B+ to COM so we changed it as per your diagram.

Thinking the Y and Z axis would be the same I was examining the wires on the Z axis (typo earlier) but all I could find were two pairs with a resistance of 2.4 and the 2 purple with a resistance of 0.4,