Geeetech

I am trying to get a 3D touch sensor set up, but I am getting some inconsistent Z readings. It seems like every time I run the Auto home I am getting a different result. With the same Z offset one time when I move the Z axis to zero it will be above the bed by 1mm or more, and other times it will press hard into the bed. I have not tried to print with it becuase I can forsee an issue with the nine point test if each time it is reading random values.

Is there a setting that could cause this? Could there be a bad wire connection? Or do I just have a bad Sensor?

I can deploy and stow with the menu commands, and the auto test functions just like it is supposed to (as I far as I can tell from watching youtube).

Does anyone have any ideas?

I don't have an idea but I can confirm your problem.

I had the same issue with my A10 and 3DTouch. I spent hours laying on the floor with my eye at bed level, making fractional mm adjustments, but it would always do the same thing you report.

I finally gave up and tossed the probe into my parts box. I may try it with a printer that has better firmware or I may not.

It's more important that I am able to print, so I just keep an eye on the first layer and adjust the leveling screws on the fly if I need to.

Your all not crazy, its the 3D Touch sensor.
Its garbage.
Throw it on a decent board like a Duet3D and do some basic testing via the usual process

- Set Z=0
- Raise Z+10
- execute G31 S-1 to report probed trigger

Results below from a Macro that cycled 12 times with a 2 second pause between every movement

3.250
3.352
3.625
3.632
3.275
3.220
3.358
3.463
3.625
3.612
3.678
3.630
3.618

Rule out the mount and bracket as this is a solid mount to the frame on a custom CoreXY machine I have.
Because I bought 3x3D Touch units, I grabbed another fresh one out of the pack and looped the same cycle:

3.158
3.117
3.283
3.194
3.241
3.682
3.363
3.186
3.714
3.621

I stopped the macro here as its pretty consistent with the last readings - I didnt bother testing the third unit... But I did plug in a BL Touch from another printer:

3.055
3.058
3.052
3.053
3.058
3.054
3.056
3.058
3.055
3.056
3.058
3.054

As you can see, not a variation beyond 3.05x which is more than Acceptable for our FFF printers.
In my mind the $65 I bought the 3x3D Touch units, would've been better off on a single BL Touch leading to less wasted filament and time lost trying to sort out the issue.

Most printers get to .01 mm and the 3D Touch has a error factor that effects our prints - EVERY TIME
You will have more success by manually leveling, or get a legitimate BL Touch that at least has far better error resolution (.0001 vs .1)...

That is an awesome post, JahNix.

Thanks for taking the time to collect the data and post it.

Now, if only the mod would sticky this.