3D kinematic probe

This design was inspired by Andy Pugh's videos:

I am making my own tips with a 4mm thread and 3mm tip following:

In my design, I added adjustment screws to the center hub for aligning concentricity of the tip.

I like to 3d print designs that are complicated before I build them on the mill or lathe. When I printed the housing, I intended to use the 3d print simply to verify the drill/ream hole setup for the pins. The print looked good so I did a cleanup pass of the shaft on the lathe and had a working probe! When I used the mill to drill/ream some delrin, one of the six drill/ream positions was off a little. End result is my 3d print "prototype" 3d probe is more concentric than my milled delrin probe.

I had some spare 5mm pins but needed to use a dremel to rough cut the length the pin lengths are not critical in this design. You may want to redesign or use Andy's files to use smaller pins.

I used a center hub made from delrin. I added adjustment screws that slightly bend the delrin to center the tip. I think this would be ok with abs or nylon. Not sure about other printed plastics. (It doesn't require much adjustment but you are adding stress.)

Print Settings

Printer:

JJT custom makerslide

Resolution:

.15

Post-Printing

Finish steps

I finished this part off with a light cut of the shaft using a lathe which gave me a better surface for gripping in a collet. Depending on how you mount the probe this may not be necessary.

I reamed the pin holes for a better fit. Depending on how dialed in your printer is this may not be necessary.

I milled a simple PCB and soldered some solder wick to make contact with the precision pins. You could try soldering directly to the pins.

I had a spare spring laying around. You don't need much spring force to keep the center hub pins against the main body pins.

Category: Machine Tools