Hello everyone…And apologies in advance if this has been covered before , I tried searching the forum with no luck yet
Longer B1 20W , with added y axis extension rails
Latest and greatest version of Lightburn (as of 4/19/25)
So when I connect the machine it travels to the correct corner location for homing but once it gets there it won’t complete the cycle and jackhammers there till I hit the e-stop. Attached are my current Machine settings , which hopefully I’m just missing something easy…
What’s the history of the machine? Did this previously home correctly? What’s changed?
How are you determining correctly location?
Can you confirm that you have limit switches for X and Y at the homing corner?
If so, are they connected and getting physically actuated? Try manually actuating to see if you can get the homing cycle to complete. Note that the laser head need not be anywhere close to the corner when you do this. If manual actuation is not working then this is likely to be either a bad switch or wiring issue. History of your machine will help inform next steps.
When homing cycle begins and I manually press the switches it does stop and I get ALARM:8
Homing fail. Cycle failed to clear limit switch when pulling off. Try increasing pull-off setting or check wiring.
Machine is brand new out of the box , assembled with the extensions…Initially it tried homing to the back right corner so I switched setting $23 to True on the X & Y axis
If it stops when you manually press the limit and doesn’t when the machine is homing then it’s not hitting the switch.
With the machine powered off, move each axis to the limit switch, one at a time. Do you hear the switch trigger on each axis?
When homing, if the machine stops when you manually press the Y axis homing switch then the switch is working. If your sure the Y axis homing switch is being actuated when you try to home the machine you may need to adjust the Homing Pull Off setting. Try increasing the Homing Pull Off setting slightly and see if that helps. Try changing $27 from 2.0 mm to 4.0 mm and see if that helps.
When homing the Y axis should activate the limit switch, then it should back off the switch slightly. If it doesnt back off enough to deactivate the switch you will get an error..
I have a different machine but just as a reference I looked at the settings to see what i had. I don’t see anything unusual on yours that would cause this but the Homing Pull Off $27
Mine/Yours
Homing Feed Slow $24 200/ 25
Homing Seek Fast $25 2000/ 500
Homing DeBounce $26 250/ 250
Homing Pull Off $27 4.0/ 2.0
Stopping demonstrates that the switches themselves are physically and electronically working. The error message is likely due to how you are actuating the switch. Try actuating each limit switch very briefly twice with a short interval in between. That will simulate a homing operation.
If this works correctly then your issue is purely mechanical. Slowly move the laser head manually toward the switches. Does the machine reach and actuate both X and Y limit switches without being impeded? If not, identify what is impeding the movement and correct it.
Were you instructed to do this? Typically machines are configured correctly out of factory. Making a change like this will likely cause issues downstream. Those can be remedied but the concern is that there may be a more general assembly issue. If you’re uncertain I’d advise just continuing forward and resolving the homing issue first, then dealing with any potential fallout.
That’s all were dealing with here is the homing issue. Changing the Homing Pull Off isn’t going to cause any other issues. We know the limit switch will activate manually, we’re pretty sure the limit switch is activated when the machine is homed. And even when he is getting an Alarm 8 it is telling him to “Try Increasing pull-off setting or check wiring”. And we know wiring is good because he can activate the limit manually and the machine recognizes that. So i only see three possible causes for this.
Either the limit switch is not being activated on homing
The Pull-off setting needs to be increased
The Limit switch is flakey and not reliable
But i gave my opinion and its up to Chris how he wants to continue.
