URX 3 and 3.1 side and bottom picatinny rails set for M4 AR15 AK and others

cults3d

Recently I got a riffle with URX 3 style barrel cover. It's great in all aspects in the same time I found myself in difficulty to find picatinny rails that match this system. Keymod and M-Lok are not fully compatible if you wander. So ... I reworked one Keymod set to make it somewhat fit to the URX guard. It came quite nice so I decided to share it with you. URX 3 require 40mm space between screws. The screws are 6mm OD, 10mm OD heads. I was lucky that the riffle was delivered with all screws on it. You may need to drill a bit the hole for the screw and for the screw head by hand. Not a problem, just be patient and drill slow. Rails are reduced in width to 20.8mm instead of 21.2mm to allow for some printer innacuracy. Also reduced in height to just 5.8mm to be in line with URX rails ( cut in Z so that the picatinny raiser is removed, only the rail is kept ) . That's not a problem, because of the URX design you will have enough space or to say depth below the rail to fit the mount. Print with 8-10 layers for bottom and 5-8 layers for perimeters. Top can go with 5 layers. Infill is at 30-40% honeycomb, rectilinear pattern for top finish. If the print come out a bit rough you may need to sand it a bit to smooth the top of the rail.