Losing steps/position, again

[Doddy]

Full reveal: I believe 300VA is enough for you and there's an air of cost-consciousness in your posts. If you're happy to suck up £20 extra for a pretty-much guaranteed future-proofing then go with it. You'll regret not doing it if you later need it, you'll probably not regret going 500VA if you don't need it.

[ngwagwa]

While being cost conscious I don't mind paying a little extra for future proofing, Thanks

[ngwagwa]

Right folks.
I have the 36V PSU kindly donated by Doddy installed an powered alongside a DIV268N to drive the X axis

BOB connected to the driver as follows:
5V connected to DIR+ PUL+ EN+
EN to EN-
XDIR to DIR-
XCLK to PUL-

I have found the correct 4 wires for the stepper and which are pairs - does it matter which pair is connected to A and B on the driver and how do I know which is + or - ?

I think the only missing thing is the dip switch settings

[Doddy]

Stepper: If it goes in the wrong direction, swap one pair.

Pull the EN signal for now - without the enable signal the driver defaults to ON. Once you get it working then re-assess if this is part of your e-stop strategy.

DIP-switch, start with 8 micro-steps and maybe 2.5A or thereabouts. If the motor gets uncomfortable warm then think to reduce - but that current should be safe.

[ngwagwa]

Stepper: If it goes in the wrong direction, swap one pair.

.

I am just getting a knocking noise - no movement.

I forgot about the 5th and 6th wires from the steppers. They run from the stepper to the underside of the cabinet - I will try and trace th- this may take some time.....

UPDATE
I have manage to get underneath (glad the router wasn't sat on a table) and it looks like the rogue blue and white cables are connected through the umbilical (the wiring diagram I have does not show them). Thre are several identical multicore cables going from inside the cabinet through to the underside and as my arms aren't long enough I am going to have to leave it until tomorrow as I don't want to cut the wrong ones.

[Doddy]

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.

[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.