Z-probe broken?

Sovol SV06 Plus ACE
1

Hi,

Had my printer for about 9 months now, just switched it on for the first time since Xmas.

The homing routine failed, when I went to do my first print. Luckily the toolhead was high enough off the bed that it didn’t collide, as I don’t think that the z-probe is working.

I’ve tested it by:

  1. putting a piece of steel underneath the tool head, and touching the nozzle with the steel

  2. shifting the gantry up, and running the homing routine, and holding the build plate underneath the nozzle - the motor just pushed down on the build plate, and didn’t stop.

I have not run a calibration, as I believe this might crash the nozzle into the build plate, if the sensor is broken. Perhaps it’s not though, and I’m being overly cautious?

So…

Should an LED change state in the tool head, based on the output from the z-probe? I have two LEDs lit, one red, one blue, they don’t change state, regardless of metal underneath the toolhead.

Is there any more in depth info I can get about this printer? Apparently they are not as open source as I first thought! (Having now tried to find out some info). If I do need to replace the z-probe (or anything else in general), how do I do it?

Here’s a pic of the toolhead, powered on.

PXL_20260305_204045025.MP
PXL_20260305_204045025.MP2117×2018 305 KB

I’ve read several other posts about z-height issues, but they seem to either be for other printers, or some other calibration issue, so different to my issue.

Any advice much appreciated.

2

The Ace printers do not have a conventional Z probe.

The hotend and nozzle are mounted on a loadcell. When the tip of the nozzle touches the buildplate the signal from the loadcell changes. Sovol has a custom add in that monitors loadcell output durring “probe” moves. That module (hx711.py) then creates a virtual switch that is passed to Klippers [smart_effector] module.

Put something solid (a coin works well) on the plate and home the Z axis. The motors are not powerful enough to damage anything other than the plate surface coating. If that goes well remove the coin and home Z again.

FWIW Klipper now supports load cell probing without custom modules but the configuration is somewhat difficult.

3

Hi @cardoc ,

Thank you for this information! I’ve done as you said, and it calibrated OK. I was probably being overly cautious, but I wanted to avoid the headache of damaging the plate.

Thanks again for your help.