Solved Sensorless homing, difficulty configuring.

[Telescopic]

Printer Model

LDO Voron 0.2

First, please confirm that the home position of a Voron 0.2 is when the toolhead is positioned in the back right corner. If that's [0,0], then the front-left corner of the bed is [-120, -120], right? The Mainsail dashboard seems to confirm that orientation.

I can move the toolhead to the right side with "M28 X0" and to the rear with "M28 Y0" I've done this repeatedly while getting the values for SGTHRS.
I add those values to the config file and restart.

On startup the printer seems to take wherever the toolhead is positioned as the home location.

I'm missing something here. I hope my description isn't so confused that someone can't tell me what I should be doing. Thanks.

 

[GetJava - Frem3D.no]

You are correct in that you will home to the back right corner, but your front left corner will be 0,0. So your homing point will be 120,120ish

 

[claudermilk]

You coordinates are correct. Are your trigger settings too sensitive? What are your driver_SGTHRS values under tmc2209 stepper_X and stepper_y? If it's too high, they will trigger too early and register the axis home incorrectly.

 

[shiftingtech]

First, please confirm that the home position of a Voron 0.2 is when the toolhead is positioned in the back right corner. If that's [0,0], then the front-left corner of the bed is [-120, -120], right? The Mainsail dashboard seems to confirm that orientation.

I can move the toolhead to the right side with "M28 X0" and to the rear with "M28 Y0" I've done this repeatedly while getting the values for SGTHRS.
I add those values to the config file and restart.

On startup the printer seems to take wherever the toolhead is positioned as the home location.

I'm missing something here. I hope my description isn't so confused that someone can't tell me what I should be doing. Thanks.

Home and 0,0 are non the same thing

 

[Telescopic]

You are correct in that you will home to the back right corner, but your front left corner will be 0,0. So your homing point will be 120,120ish

Thanks for the correction. Three things make sense, but the designers had to choose any two:

1. It's usual for us to think of cartesian coordinate systems beginning at the lower left, and increasing to the back and to the right.

2. The most convenient spot for the printer to home is at the back, out of the way.

3. It's usual for us to think that home is [0, 0].

For the Voron 0, #1 and #2 are true.

 

[Telescopic]

You coordinates are correct. Are your trigger settings too sensitive? What are your driver_SGTHRS values under tmc2209 stepper_X and stepper_y? If it's too high, they will trigger too early and register the axis home incorrectly.

Bingo. You got it. I had much higher values for driver_SGTHRS-- hey, they worked a couple of times. When I set lower values (much lower, almost 1/3) everything works. Thanks!

 

[claudermilk]

I'm glad it was that simple. It took me a little while to get the values dialed in.