Hello all. My left and right jog distances have become different from each other. Same for up and down. For example, I have the jog distance set at 1". I can jog right 1" using the on screen arrows with no problem. However, jogging left only makes the laser move a few millimeters. Same thing with up and down. Up is fine (travels the correct 1") but down only travels a few millimeters. My GRBL setting all look correct. Also when I am actually burning a project, everything works perfectly fine and there is no problem. Its just jogging where things are messed up. I turned on “Show all” on the console and here is what I got: when moving left: $J=G20 G91 X-0.009 Y0 F157.48 which is bad. When moving right:$J=G20 G91 X1 Y0 F157.48 which is good. So what do you think is causing this leftwards “X-0.009” yet my righthand movement is the correct “X1”? All my GRBL settings look good.
Without an error message, that is really strange! Do you have Soft Limits (parameter $20) turned on?
If Enable $J Jogging is turned on and Continuous Jogging is enabled, then the jog distance depends on how long the on-screen buttons remain “pushed”, rather moving the preset distance, with a minimum distance that isn’t the preset distance.
Do you have both of those settings turned on?
If so, turn off Continuous Jogging and report if the motions now correspond to the preset distance.
Also, if you have a wireless keyboard & mouse, this may be a good time to replace the batteries, because weak batteries cause all manner of weird behavior.
If you jog it right by two inches, can you then jog it left by one inch?
That would implicate a problem with the machine origin / homing setup. If the controller thinks it’s near the leftmost limit, then it can start a jog, but will stop at the limit.
Things to check:
- Does the machine home correctly when it’s turned on?
- Does the
Machine Originmatch the home switch location? - Does it jog properly with
Absolute Coordinatesselected?
So the problem turned out be a very silly thing. Your post (and others above you) mentioning homing made me think to just home the machine. Note that I rarely home the machine because I’m always working on odd projects. Well anyway homing seemed to reset everything and now my move commands work perfectly! Thanks everyone
What it does is tell the controller where the laser head is on the platform, which it needs in order to move the head to other places.
Unless you have a compelling reason to not home the machine every time, always homing will save you plenty of head-scratching later on.
Fire The Laser! 
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