Focus test negative starting point

using ruida controller I was trying to set the focus test to a -3mm to 10 mm but the focus test wont allow a negative number to be entered. this would allow a better gauge to check focus. Or is there a way to set the z position to zero without using focus z button so you could move the bed to like 3mm and set the z to zero and then run the focus test

Ruida won’t accept negative numbers for any axis - there’s no command I can give it that will position it that way.

If you zero’d the Z to the bed of the machine, that could work - it will obviously be too close, and all other numbers away from the head would be positive.

thank you. Is there a way to zero the z bed manuely? Right now when I turn on the the laser it defaults to 3000 and then you need to auto focus to get it to set to zero. If i adjust the auto focus probe lower so the the head is at bed hight or even 1 mm above I run the risk of the head hitting the bed.
By the way love the lightburn program and all you have been doing with it.

Please egnore previous entry . I found one of your comments on the subject that sort of helps. Thank you. Keep up the good work.