5mm wide opening. I will add some parts later for larger wrenches
Assembly: Slide threaded part 3 thru part 2 and thread handle on which will hold everything together with the allen wrench inside
Print handle at 101.5% for thread tolerance. Part 2 was given .6 tolerance in the design process but may need scaling depending on print settings. Handle has a 45 degree chamfer at the top on the inside so only a 10mm diameter circle will have to be bridged so this should print fine with no supports.
update: 2/17 adjusted locking ring for a tighter fit on the wrench and added a multiple size wrench locking ring