Why do I always have so much trouble with endstops?

I don’t think I’m looking for any help (yet), but I just want to know if anyone else has trouble setting up endstops on grbl mega 5x, too?

I’ve built 6 iterations of cnc with mega 5x, and two with vanilla grbl on the uno. Vanilla, no problem. Mega 5x, they always behave erratically until they don’t, and then it’s generally OK.

Yesterday i spent 3 hours troubleshooting them on my primo rebuild. First, only one would respond. After jiggling wires, double checking the solder, verifying continuity at the crimped connectors, and verifying the switches, i flipped the settings to NC and all but one of them worked. That last one would sometimes work, sometimes not, sometimes go for just a second then trigger. Reolaced the switch, same problem. Added some capacitors, no change. Every complaint for endstops is met with “it’s noise”, so I bought a bag of those and it hasnt fixed my problem ever, nor has the shielded cable i tried twice. Removed the capacitors because they ALL failed again, and flipped them back to NO, then they all started working sometimes. Recrimped the ends at the ramps. No change.

Finally, i reflashed the firmware, and they seem to be working. Good LORD was that ridiculous.

But is it just me?

1 Like

Are you using “naked” switches, or the 3d printer end stop circuit boards with LED’s on them? I’ve never been able to get those LED ones to work in NC mode, so I end up cutting the switch off the board and wiring it directly to the CNC Shield controller, then I had to add the capacitors to solve a noise problem (but my switch leads are inside a 6-conductor shielded cable with my motor leads, so noise isn’t really a surprise).

Also, are these 3 different sets of controllers, or reusing the same controller? Maybe there’s something flakey with the reused controller.

Regular switches, no leds, and at least two controllers. I THINK there might have been a third in there, but I’m not positive.

If nobody else has heard of this, I’m ok with blaming my controllers.

Sorry but I’ve never done the grbl mega setup, just the CNC Shield/Uno stack.

1 Like