I’m using a generic GRBL board with a machine I built myself. I’ve used this machine before and it was working, but this time I’ve made some upgrades: size and limit switches.
Im pretty sure I did everything I need to do in lightburn pertaining with homing, but I could be wrong. I uploaded a screenshot of some settings I changed.
The machine refuses to move when I hit the home button. If I use the set laser position tool, the laser will move. I dont know where it’s trying to go everything I use that tool, but it is moving. Its always trying to go right and to the rear some. I have to shut the laser down everything I do that so it doesn’t reach the limits.
I don’t know what I did at one point, but when I touch the limit switches, I could see in the console that the machine saw the switches triggering. The machine doesnt want to move during homing.
I uploaded the most resent GRBL using xloader. I could also jog the laser around using ESTLCAM as well. I didn’t try to get the machine to home using ESTLCAM.
This is what im seeing in the console after trying to home:
$H
ALARM:9
Homing fail. Could not find limit switch within search distance. Defined as 1.5 * max_travel on search and 5 * pulloff on locate phases.
Will it attempt to home with the switches disconnected? You may have to halt it, as it will run the working area distance.
If/when it does move, does it go the right direction?
Just guessing here…
Is your board ‘3d’, meaning does it support a Z axes? The normal cnc will raise the Z axes before moving x and y to avoid ‘hitting things’… could that be enabled?
It won’t move when the switches are disconnected. Tried anyways even though the switches are NO.
The machine does move in the right direction now. I had to invert both X and Y.
My board does have a third dimension but I do have the Z Control disabled.
I’m aware that the z does move up some before homing, but a switch isn’t involved with that movement. It should move the x axis shortly after that z movement. It’s just not moving anything. It is doing something, its just not moving.
Is this a cnc machine or dedicated laser engraver? Do you have a Z axis connected with limit switches? If you have a dedicated laser and no physical Z axis connected you may need to modify your firmware to skip homing Z in the config.h file.
There is nothing being used with the z axis. I think you might be right.
When I try this machine using ESTLCAM, I can clearly see that my limit switches are working as that software allows to test. If I jog the machine all the way in either X or Y, it will trigger the switches. ESTLCAM won’t home either, but I can clearly see that it’s trying to home Z first. if I abort Z, it shows its trying to home the others but there not moving.
In LB if I manually move the machine to home in a triggered state and then try to jog the machine it wont let me. it says that its triggered. if I move the machine out of the triggered state it will then move. if I try to home at that point, the X and Y steppers are holding. When the machine is not homing, the steppers are not holding. Tomorrow Ill se about editing the config file.
I had to do this recently on a diy laser engraver myself.
I made the following modifications to the default config.h file, recompiled & uploaded.
//#define HOMING_CYCLE_0 (1<<Z_AXIS) // REQUIRED: First move Z to clear workspace. #define HOMING_CYCLE_0 ((1<<X_AXIS)|(1<<Y_AXIS))
I think that was all I had to change for homing to work.
