Car CD mounted spring loaded adjustable tablet holder, should fit 4" to about 7" tablet.

Print orientation is as the pictures show.

Use a 1/4 x 20 x 1 1/2 in socket head bolt and a 1/4 x 20 nut for the knob.

The spring is a 3" tension type spring, that can be easily adjusted by stretching it, if needed,
the spring mounts between the two holes using whatever you want to use, I used some rivets I had lying around, trim as needed, I also used some CA on the pin to keep it from falling out.

This mount works great on a table top too.