I made this as simple as possible, you need a 200X200 bed minumum to print it in one go per piece.

There are 3 objects each to be printed twice.
Main object is the leg, designed to sustain 2 Kg of product at 20% infill, much more at 100% infill you need two, their square hole is there to put through an aluminium 20x20 profile as long as your needs are, mine is 300 mm long, infill the nuts and put the bolts trough to hold it fix, by losening the nuts you can slide to open/close the gap as needed.
Second object is the grabber piece, you need two as well, plus two M5 nyloc nuts and two M5 by 100 (or at least by 70mm) bolts and two springs interior diamter 5mm or 5.5 mm
Third object is there in two versions, version for smaller PCB to hold and version for holding thick objects like... my tablet, yest this thing holds my tablet while I use it to film things with it like how to do something by hand, once it is fitted in there I can go ahead and work under the camera no problems.  You will need two of each.

For the price you have access to download the STL file that you can print yourself.