FAQ and Troubleshooting

Sensor errors during homing

If you see errors like this:

Error during homing z: Sensor error (ldc status: UNREADCONV1 ERR_ALE)

This indicates an "amplitude error", and is usually caused by one of two things:

• Eddy coil mounted at wrong offset from nozzle (either too high or to low)
• Wrong drive current is set for coil

The default drive current is 15. In some cases, some additional current can help, but it can also introduce errors in the other direction.

See "Drive Currents" below.

Sensor errors during tap operations

These are the same cause as errors during homing, but if the errors appear only during tapping, you can increase your drive current for tap operations only. See "Drive Currents" below.

Tap stopping too early with the toolhead in the air

This is caused by the tap threshold being too low and triggering before nozzle-plate contact occurs. Looking at the plot can help identify what's going on.

Also verify that there is no filament on your nozzle. Tap detects physical contact, but if there's a bit of filament at the tip, that will count, too.

Tap erroring with "Probe completed movement before triggering"

This is caused by one of two things:

1. The tap threshold is too low, and a tap isn't detected before the toolhead reaches the target position (default -0.250).
2. The base sensor calibration is too far off, and actual zero is lower than -0.250 on the Z axis.

To check the second one, put a piece of paper under the toolhead and manually move the toolhead to 0. Then keep stepping it downwards by 0.1 until you can no longer move the paper (or it's very difficult). If this is below -0.250, you can redo calibration, or you can set a lower tap target Z; but be aware that this increases the amount of nozzle-build plate contact.

If it's not the second one, then looking at the plot can help identify what's going on with the threshold value.

"Already sampling" error

If you see errors like this:

EDDYng Already sampling

This often happens after a QUAD_GANTRY_LEVEL aborts due to increasing offset values. Unfortunately the way that error is reported doesn't seem to go through the normal command error paths. A RESTART is required. (TODO: add a PROBE_EDDY_NG_STOP_SAMPLING) If you see this and there wasn't an aborted QGL or bed mesh, please file a bug.