Been running a chinese laser on a mini gerbil 3 board, it stopped working and upon powering on the gantry can be moved by hand (slowly) and there is no power to the motors. Went through lots of fault finding steps from previous threads and with Awesometech, to no avail. Tried a new mini gerbil 3 board, same problem.
If I move the gantry by hand even very slowly, it will move say 20mm and the motors will energise and the 2 orange LED’s on the board that confirm the limit switches are reached will come on. When I give the command to home, the head will move say 20mm and then stop and the orange LED’s will go out and no power to the motors. I then get the below message.
Homing fail. Cycle failed to clear limit switch when pulling off. Try increasing pull-off setting or check wiring.
The homing cycle is this, move x axis until limit switch is detected, move y axis until limit switch is detected, move off both axes a small amount (defined in settings, typically 3mm) to open switch and slowly move back to contact the switches.
When it homes, does it pull off of the limit switches on both axes and then return to limit switch?
Before the fault, upon powering up lightburn and the laser, the motors would be energised and I could do a homing move and start engraving, now there is nothing. That is what I am trying to get to the bottom of, not sure if it’s software or hardware? 5V & 24V is going into the board.
I still don’t understand, sorry. Is the state above the current state of the machine or was it acting this way previously and now will not move at all no matter what you do?
The machine was working fine until a few weeks ago, the above is the current state of the machine. It will now not work at all apart from when you move the gantry by hand say 20mm, the motors will then energise, if I do a homing command it will move a very short distance and then everything is de-energised again.
Auto home was enabled, but I have tried it with it disabled with no luck.
Ok, do an experiment for me. With the laser somewhere in the middle of the bed restart the laser and make sure it’s connected to lightburn. Go to the move panel and click get position. It should report 0,0.
Then, using the arrow keys attempt to move it up 10mm and right 10mm. If it only moves in one direction manually move the laser head on the axis that didn’t move a bit and try again. If it then moves, even a little bit, on that axis I think you have a bad stepper motor.
Most likely, since a bad stepper motor would only affect one axis.
Is that the same board the machine came with? Are the stepper drivers built in to the board or a replaceable item? My machine came with a board that had the drivers built in. I fried it and replaced it with a different board that had separate stepper drivers that needed to be installed.
Obviously you double checked all connections on both the stepper motors and the board.
SOLVED.
The red dot pointer on the laser has a twin wire positive and negative 5V wire going to it through the flexible cable chain protector. It had snapped completely with just a whisker of cable sticking out of one wire. Hence when I moved the gantry by hand sometimes the motors would energise, other times the wires were shorting out. The mini gerbil 3 has a resettable fuse that was obviously blowing and then resetting itself. All working fine now.
I’m glad you were able to track down the issue. Something like that could go unnoticed very easily if you weren’t diligent in checking the wiring. Happy Lasering!