LM3 not homing properly

This is linked to a previous issue I had where I thought I had solved the problem. Just started machine for a project and when I home the laser moves to the correct position on the x axis but does not move down on the y axis. Consequently, if I home a few times, the laser will move further and further upwards. I I try and jog down, the machine will alarm (out of machine working area). It is as if the machine is resetting it’s home position each time I select home. Any suggestions appreciated.

This may be mechanical binding because it seems to be worse in one direction.

A lack of motion in the Y direction when homing can be caused by a mechanical concern, an electrical concern or a poorly selected setting.

Do the Jog buttons move in the correct directions by the correct amount? Testing by repeatedly jogging 100mm in all four compass directions may show accumulated lost motion. Alternating 100mm jog commands should offer precise repeatable movement with no accumulation.

This may be a symptom of a mechanically loose drive sprocket.

Please confirm that the set screws on the motor sprocket are tight by attempting to tighten them slightly. Homing behavior is mostly in one direction so we can’t disprove lost motion in both directions with homing operations.

Slowly move the gantry along the Y axis to confirm it moves freely without binding. Binding can cause lost motion when the drive motor slips or when it stalls. Binding can have a directional bias; the engraver could bind more severely when it moves away from the origin than when it moves toward the origin (or vice versa).

With lost motion the engraver will count steps (and keep counting them) without sufficient movement until wildly incorrect locations and offsets accumulate.

In LightBurn, in the Console window, we can ask where the engraver control board believes it is and which workspace offsets may be accumulating. Please request those reports by typing the following into the Console window in LightBurn:
pressing enter after each one.

Please copy and paste those results into a reply here.

Please let us know what you find.

Hi, at the same time as asking these questions on here, I also opened a ticket with Ortur. After some back and forth, it transpired that the washers on the idler brackets were on the wrong side. Whilst I have a mechanical engineering background and this made no sense to me, swapping the washers over fixed everything! I can only assume that the washer location was causing the idler wheels to bind and the motors were being instructed to stop during software driven operations (jogging was fine). Anyway, all is now well and sincere thanks to everyone who took the time to provide advice.


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