I just got an old Ender 3 for cheap and wanted to replace the crappy extruder with a nicer bowden extruder of my (now) direct drive Kobra Max. When I connect the new stepper, nothing moves. It's a longer stepper and a different manufacturer. Is the wiring different or VREF wrong or are there other reasons why it wouldn't move? The driver is good, since the old stepper is still working.
NEMA motors should all have the same wiring, it’s part of the standard in the nema specs, might be off on voltage, which would make sense. Check the specs on your motor and pull out a volt meter and check/adjust its voltage to match the new motor’s needs.
As long as both have the same number of wires, that is.
This is, of course assuming the physical connections are all dandy. (It’s possible something came loose in the conversion?) you’ll have to open its case up any how to get the volt meter on the tuning pot anyhow. (Positive to the pot, negative to ground somewhere. I’d drop a guide but specifics change with boards.)
Just to give more details, NEMA 17s can have 4, 5 or 6 wires. 4 wire versions are bipolar while the 5 and 6 wire versions are unipolar. While it would be nice if NEMA 17s were all the same, they aren't. The standards apply to dimensions but not electrical specifications. Windings will change from manufacturer to manufacturer but are ultimately limited by its size. Because of this, all NEMA 17s will be capped in torque to a degree. Increase the case size with a NEMA 23 and you get more space for more windings, etc.
Edit: All this said, it doesn't matter too much if steppers are mismatched. It's just a matter of tuning voltage and steps. I prefer to have the same steppers in a project since it is much easier to configure that way.
To clarify what I meant, the Pinouts are all standardized- or should be. OP shouldn’t have any issue slotting in the old wires (unless it’s a different wire count, of course.)
If it is a different number of wires OP will certainly be having a hard time adapting it… (that becomes a firmware issue; and I just don’t want to know the headache a creality main board will cause with that.)
Just to give more details, NEMA 17s can have 4, 5 or 6 wires. 4 wire versions are bipolar while the 5 and 6 wire versions are unipolar. While it would be nice if NEMA 17s were all the same, they aren't. The standards apply to dimensions but not electrical specifications. Windings will change from manufacturer to manufacturer but are ultimately limited by its size. Because of this, all NEMA 17s will be capped in torque to a degree. Increase the case size with a NEMA 23 and you get more space for more windings, etc.
Edit: All this said, it doesn't matter too much if steppers are mismatched. It's just a matter of tuning voltage and steps. I prefer to have the same steppers in a project since it is much easier to tune that way.
I use a tevo tornado which is similar in many ways to an ender3 and added a direct drive extruder. I ended up needing to change the wiring for the stepper motor because it just sat there jerking around but not moving. I don't recall if I used a meter to measure resistance or if I just swapped wires until I got it working but it prints perfectly today and has for years.
To do it I think I had to use a small screwdriver to push in the little barb that holds the pin in the connector (on some you can lift a little plastic tab on the connector to pull it out) then I could just push it back in place. Make sure you don't disconnect your stepper while powered, it can toast your controller.
I checked the pinout with a multimeter yesterday and the don't seem to be the same. I'm pretty sure this is the issue. Thanks for mentioning pinout as a source of issues.