As the title says..... I am using the cannot get it to home everytime the command "Home All" is excuted the Z axis moves up about an inch and "Alarm 8-Homing fail. Cycle failed to clear limit switch when pulling off. Try increasing pull-off setting or check wiring [ $H ]" Now the issue isits no where near the Hard limit switch in order to trigger it, I have the home all set to raise spindle up .....But it only moves an increment and then stops I have tried to set the PULL-OFF to 30 (I set it back to 5 after I tried 30) and it still does it? I have installed new limit switches, This is my first machine in case you couldn't tell lol so the learning curve has started....boy that hill looks STEEP! LOL Thank you in advance for any direction to assit with this issue
Hi Larry. Don't feel bad, amigo. Limit switches and homing is the number one problem everyone has with GRBL and DIY setups. Very few times do setups work on the first try. It seems that GRBL / BB might still think the switch is tripped even when it's not. I assume your running your switches normally open, as you have GRBL in standard limit pin setting. Check your wiring for grounding. If you have a lot of EMI (inducted line noise) it could do it too. Try to isolate your wires and CNC from sources of EMI. Your switch debounce is set at the top limit, so it shouldn't be this. Lastly, check that your axis movements are not missing steps. Since your Z axis works against the pull of gravity it could be that it isn't moving the prescribed pull off distance. These forums are pretty good so if you look around for solutions, you'll find something. Good Luck!
What does the troubleshooting tab look like (screenshot please) when the limits are not triggered? On the switch, sure you wired to C and NO, and not by mistake to C and NC
Thank you for assisting, hear is the screen shot you requested I also went back and checked all grounds, reset everything and started over, I pulled the limit switch wires out of the drag chains so that they have no other wires around them. When I execute home all the z gantry starts and raises up and its as though the limit switch is not even installed it wants to bottom out! I confirmed that the switches were working prior to executing the home all command and it blows right past the z hard limit switch? And yes the limit switches are running NO
Eh. Can you take a pic of the z axis setup..? Which machine are you running? Do you hear a grinding or stuttering sound when the Z stepper is moving? Also, its a little hard to make out the Z limit condition from the screenshot. It kinda looks like Z shows triggered, and I assume it's not physically triggered. When you physically disconnect all limit wires from the black box does this condition go away?
It's a 1000 x 1000 utilizing Nmea high torque motors, using the "workbee" config file loaded into the Black box....the video shows it at lease hitting the limit switch and bouncing back .....but that horrible noise on the bounce back??
Long shot, but you don't maybe have the limit switches plugged in incorrectly, for example Y switch in X port, or similar? (wondering why the switch triggers before its hit, remember an older thread where someone had a similar result, had wrong switch on wrong plug) Other than that, consider getting some of these: Xtension Limit Switch Kit - built in EMI filtering may help if that was just an EMI related false trigger
Ok Peter thank you, I have 3 of the Xtension limit switches on order and they should be here by Wednesday once I install I will report back! UPDATE I double checked my wiring and Peter as you stated I had the limit switches inserted incorrectly after fixing I am happy to report we are "Homing" correctly!!! THANK YOU ALL FOR THE support! That hill doesn't "feel" as steep now, I know I will have a ton more questions but I am feeling very confident that if I get stuck there is a great support forum to help!!!
