Stepper replacement with TMC2208

Hello Guys

My printer actually has steppers with reference:

42SHDC4047Z-23B the spec I found are:

Main Features:
- Step angle: 1.8 degree
- Number of phases: 2
- Voltage: 3.96V
- Current: 0.9A
- Resistance: 4.4 ohm
- Holding torque: 0.34 Nm
- Operating ambient temperature: -20 Deg.C - 50 Deg.C
- Operating environment humidity: 90 percent
- Axis diameter: 5mm

I have installed TMC2208 with Vref set to 1,2.

I tried to replace original steppers by 42BYGH 1.5A (17HS4401

However when I mound those ones the shaft tries to move but is not working.

I can not understand exactly why?

Can you please give me some idea?.... The driver and the cable is working fine with the original stepper...

Just to bring more info.... My main board is an MKS gen L (12VDc supply) and I have all drivers configured to 16 microsteps.

However for the extruder I have a DRV8825 (also a 16).

On this DRV I have the opposite.... 17HS4401 works perfect and the other model of steppers do the same issue that I explained before (is like trying to turn but just jumps a bit).

Thanks in advance

Edited 2 time(s). Last edit at 01/02/2019 12:44AM by davidcgu.

Have you checked that the wiring of the cable is the same on both types of steppers? Wrong wiring will cause the kind of problem you experience.
Check the wire pairs which correspond to each coil - if you short them, and turn the motor by hand, you will that it needs more force. If the coils are not on the same wire pairs, you will need to change the cable.

It was making me crazy as I was using original cables.... now solved... and yes... wiring problem, apparently the pins on the steppers from the coils are twisted in one model respect the other one.

Thanks a lot and have a great new year.

Regards from Barcelona

Edited 1 time(s). Last edit at 01/02/2019 08:14AM by davidcgu.