Duet 3 Touch Probe Digitizer

[Gerrard]

Hi All,

I've had a quick look around, and I can't find what I'm looking for.
I'm wondering if there's a way to connect a digitizing touch probe to the Duet 3 board for reverse engineering purposes?

Something like this: https://www.youtube.com/watch?v=FJ8aKo_qqos

Cheers

[Gerrard]

I've been looking into this further, and it seems that simple digitizing probes are just switch based - they assume the contact surface is perpendicular to the direction of travel, and let the controller calculate the position.

So, I see that there is an output to file (M28) command, and a current position command (M114), so I'm wondering if there is a way to string these together to do move through a grid pattern - touch the work surface, then output the current position. Even if the output file was a bit messy we could clean that up afterwards...

I'll explore this further later...

[JoergS5]

@Gerrard here https://www.youtube.com/watch?v=prb60JoxQSQ and second version here https://www.youtube.com/watch?v=_OZmYQTXtEo

is a nice DIY for a probe digitizer. In fact it's a switch.

I would like to use it to proceed a damaged print.

[Gerrard]

@JoergS5 the probe part itself is covered now I think. The question now is how do we utilize this with RRF?

[JoergS5]

@Gerrard I expect solutions will be found in the CNC field. I found a few software solutions in this direction:
Esprit: https://www.espritcam.com/product/probing
Renishaw Easyprobe: https://www.renishaw.com/en/easyprobe--6092
OpenCNCPilot: https://github.com/martin2250/OpenCNCPilot
G-Code Ripper with auto probe: https://www.scorchworks.com/Gcoderipper/gcoderipper.html

But they are bound closely to specific hardware or run on a pc only. I expect a macro based solution, storing the values like for mesh compensation, could be a path.

The 3D probe will have some force when having contact to the object with the danger of destroying or moving it. So other methods without contact (maybe in addition) could be a camera or laser based solution. Same direction like 3D scanners.

[Phaedrux]

G29 mesh compensation kind of works like this already, albeit with the probe diving downward in a grid pattern and generating a heightmap.csv. The mesh isn't quite a point cloud though since it wouldn't be able to detect vertical surfaces.

Even so, someone had used this with a tiny touch probe to generate a heightmap of the face of a coin at very high detail. I wish I could find that thread now...

EDIT: Here we go: https://forum.duet3d.com/topic/8685/3d-scanning-a-2-coin-with-3d-printer-and-diy-touch-probe?_=1597808249921

[baird1fa]

I realize this is an old thread but I'm curious if any head way has been made. I was thinking of trying to do something like this with the available touch probes. I have installed this probe on my machine and written a macro to find the XY coordinate of the corner of the work piece shown here: https://youtu.be/sxFnuANYMj0?si=RC7X4tuDhhlL49RF

With the Meta commands is it possible to make reprap generate an output file using the M28 command an the M114 command to store the point cloud data. I think all that would be needed is a set of commands like move so many mm in x then do a probe, on contact save that coordinate, lift up a bit, make another move and probe. Repeat that until there is some user defined stopping point, then move in the Y direction and move back to the X starting position and repeat for as many Y directions as needed.

Is this something that anyone has done, or is there an example of this with meta commmands. I'm very new to meta command and text based programming in general.