Z stop issues and solution (endstops - not for BLTouch)

I have seen many comments that people are having Z stop issues. Some are seeing Z stops “in the air” away from the limit switch, non-repeatable Z axis calibration or occasional Z stop crashes.

I was having similar issues after loading the 4.0.6 firmware on a Balco 5.2c motherboard (without BL touch). With the original OEM firmware the printer had been working well for several kgs of filament.

I eventually realised that the mainboard was receiving intermittant electrical noise on the Z stop limit switch signal. This was being detected with the 4.0.6 firmware but not with the OEM Balco firmware. Perhaps andres excellent software has different switch debounce sensitivity than others.

My problem was eventually and completely fixed by the addition of a 0.01uf capacitor directly across the Z axis limit switch terminals.

Who is “andres”? :wink:

You are making an over generalization. Most of the people having such problem do have a BLTouch and often some wiring problems. I almost never heard of any problem with the z endstop. For the x endstop, yes and there is a fix in the firmware for that.

So I think that the problem you describe here is very specific to your printer and can’t be generalized to others.

This is a classical and valid solution to debounce the signal from a switch. But (for future readers), NEVER do this if you have a BLTouch.

I had the same problem on uk balco and when I took it apart I spotted that my board it 5.1 - so just flashed firmware for it and it works fine