Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4332803.
I really liked this phone tripod compatible mount by Redd (thing:3002681). But I wanted it to be a bit bigger so I could mount an ipad so that my kids could do piano lessons via zoom. I went chunky because I didn't want to save a bit of plastic and risk it being too weak to hold a rather expensive ipad. I made it modular so you can use it for a phone or add extension rods to fit an ipad or other tablet. I also have a tripod with quick connect adaptor so I made the base quick connect compatible, as well as, standard 1/4" threaded.
I printed in PETG and then used a tap and die to clean the threads, if you print in PLA you might be ok as is. If you are having trouble with tolerances you can print the male parts at 97% in x and y directions leaving z (the axial direction) at 100% and it will increase the tolerances and make threading it in easier.
I printed on an ENDER 5 at 60% infill, and 4 perimeters with no supports. You might need to raft some of the taller parts if you have trouble with adhesion.
The threads are: 1/4" - 20 UNC for the tripod mount 1/2" - 13 UNC for the rest of the threading I had tap and die for these on hand in a good old Canadian Tire tap and die kit so that is what I went with, hopefully it is pretty common.