I needed an adjustable mount for some motion sensors. There's a recessed hole at the bottom of the base so that you can screw it to a wall. Then the ball goes in. Next the clamp piece. I made two versions. One without knurls one with. Mix and match to your preference. I've found that having either the clamp or base knurled is good enough to get a good grip for tightening. For the best grip use both knurled parts. For the cleanest look use the plain parts.
I printed these at .2 and .3 layer heights. Both seem to work with .2 having a bit smoother operation.
The mounting holes have 4mm diameter.
The .amf files are what I used, but I added the .stl files so you could get a 3d view on Thingiverse if you want it.
Some pictures show the motion sensor holder attached, but that isn't a part of this thing.
FreeCAD
This was designed completely in FreeCAD.
It was a pain to learn it, but I really hate the subscription/cloud model of Fusion even if it is free. FreeCAD is open source and getting better all the time.
The author marked this model as their own original creation. Imported from Thingiverse.