Stallguard on CoreXY/HBot Printers

General Discussion
1

Question for the group:

Has anyone used TMC’s Stallguard (using tmc2130, tmc2209, tmc2660, or tmc5160) on a CoreXY or HBot printer?

I have successfully implemented it in my RepRap Cartesian printer.

The Klipper documentation does provide some information (Tips for sensorless homing on CoreXY). The Voron community page also has a description (Setting Up and Calibrating Sensorless XY Homing) of what needs to be done. Doing a search on the interwebs found Sensorless Homing which has a pretty good description of the process.

I was wondering if anybody had a definite example they can show as I have two questions about doing this:

  1. On a CoreXY printer are both the “A” and “B” steppers running to find the limits? I was expecting both to be running with one at the lower level for Stallguard to work but when I look at the examples listed above it looks like only one is turning so I’m not sure how the X/Y limit positions are calculated.
  2. How should the Y Axis endstop (bumper) be physically implemented? I’m thinking that it should be in the middle of the moving gantry support beam so that there is no torque on it. The X Axis bumper is just at the end of hte moving gantry.

Comments or pointers?

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I use sensorless homing on my voron2 and have not had an issue. I use a variant of the macros that I documented in the main Klipper “tmc drivers” page that you linked above. Many people successfully use sensorless homing on corexy with Klipper.

Homing of X is done by moving the carriage in only the x direction (both the “x+y” and “x-y” steppers move). Although both steppers move when homing the X carriage, for code implementation reasons, only the “[stepper_x]” tmc driver is used to sense the contact. The same is true when homing the Y carriage. In practice, this has not been an issue.

I didn’t need to do anything special to the rails/carriages on my voron2 to use sensorless homing. For other printers, just make sure the carriages hit a solid object at the end of the rail.

-Kevin

1 Like
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Thank you - that answers my questions perfectly!