This is a really easy way to mount a Havis dock or anything else that has the vesa 75 or 100mm mounting holes. None of the designs are my own, thanks to @bricbric for the arm/ball design(all of his designs are great!) I found them to work together really well. I haven’t tried it in the cab yet but it feels very solid when tightened up.
The mounting ball just needs the very top of the hex ground or shaved down a little and it will slide nicely into the dovetail slot. You could also just mount the ball directly to the dovetail but the holes aren’t currently the same size and the dovetail needed some clearance added after it came off my printer (it was way too tight). Someday I’ll try to learn some CAD and I can fix these problems properly like many of you would, but for now it’s a quick fix!
Here are links to the files: