BIGTREETECH-SKR-E3-Turbo
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bigtreetech
Stepper motor pinout
I'm confused about the stepper motor pinout in multiple ways:
- Looking at the pinout pin 1 should be on the left (marked with a square). Comparing this with one of my JST-XH connectors the mark for pin 1 is on the right.
- From other BTT boards a would have expected a pin order like "2B 2A 1A 1B" where the number matches the coils and letters A/B for the polarity. This is the order I also find in the schematics. In contrast to this the pinout reads "2B 1B 1A 2A". Do I have to swap pins on my connector cables or did just the meaning change with letters representing coils and numbers representing polarity? It would be great if this repository could explain the meaning of those stepper motor pins.
Now having the board in front of I think the PDF with the pinout is wrong:
If we follow the old naming scheme (coil = number) which is also present in the schematics it should read "2B 2A 1A 1B" or if we follow the naming convention of the trimac stepper drivers (coil = letter) it would be "B2 B1 A1 A2"
Connect the motors so that they work. For example, the original engines on the Ender 3 use engine connections other than the engines you buy online.
From my understanding it can be dangerous to bridge the different coils. Only swapping coils or polariy should not damage anything. There are many reports of destroyed stepper drivers because of wrong motor wirings with different boards and replaceable stepper drivers. Does the E3 Turbo have any protections in place so we don't destroy any of the onboard TMCs when we go for the trail and error approach? That's why I think it is important to have an understable pinout before we connect a stepper motor.