Origin not working right

[Willee (William Lee)]

Using an Xtool D1, firmware up to date.
I load a project into LightBurn, home the Xtool D1, and jog to my starting point.
I set my Origin position.
I start the burn and decide to abort using the stop button.
It stops.
I then click on the Go To Origin button and the laser moves toward the lower right corner instead of toward the origin spot … I stop it.
In the Move panel I click the home button and the laser goes to the home position (upper left corner)
I then click the Go To Origin button and the laser goes to the origin spot.

Why is it not going to the origin spot after I stop the burn?

[berainlb (PY)]

@Willee

I start the burn and decide to abort using the stop button.

Stop button raises an alarm condition. Steps/position are no longer reliable so wouldn’t surprise me if location of user origin is off.

You may be able to avoid this by first pausing, then stopping.

@Willee

In the Move panel I click the home button and the laser goes to the home position (upper left corner)
I then click the Go To Origin button and the laser goes to the origin spot.

I’m curious how this is working. As I understand it xTool D1 doesn’t have limit switches so didn’t think it would be able to home in LightBurn. I’ve heard but have not had confirmation that xTool D1 uses a sensorless homing process to be able to home without switches in Laserbox. However, I wasn’t aware that this was available in GRBL mode.

if D1 is able to home and reset origin then this would explain why doing so allows it to re-establish proper position.

[Willee (William Lee)]

The Xtool D1 will home to the upper left corner.
It must use some kind of torque sensor on the motor cause it will go to that corner without the stepper motors skipping when it comes to the rails. It then offsets itself a few mm from the corner. That is now the 0.0 x 0.0 home position.
The origin position once set (as measured from the home position) will remain in memory.
That is how I can stop, home, and go to origin and as far as I can tell it stays accurate.

I will try a Pause then Stop and see if it will then go to origin position without going to home position.

[berainlb (PY)]

@Willee

It must use some kind of torque sensor on the motor cause it will go to that corner without the stepper motors skipping when it comes to the rails. It then offsets itself a few mm from the corner. That is now the 0.0 x 0.0 home position.

This is good to know. In sensorless homing for 3D printing the detection of back EMF as the result of stepper motor skipping is used to determine limit detection. I imagine this works similarly but not sure. I didn’t realize the behavior was available in GRBL mode of the firmware.