AR15 Free Float Style Handrail

thingiverse

Lastest update: 3/1/18 7:34PM PST Finished printing. I had to grind down a little part to make it fit, but I updated the STL file as well to fix it (supposedly) If you do print this, any feedback would be greatly appreciated! Please let me know if it fits/if there's any suggestions in the comments below. My printed handguard currently has 40 shots through it, 0 signs of melting and 0 signs of deformation. I think it's safe to say that with PETG, it can withstand the heat as long as you don't shoot full auto. Replaces standard 6.75" carbine handrails. Modeled from my AR stoner upper receiver. (Please make measurements before printing) I designed it to be used with M3 screws. You'll need 8 M3 nuts, and 8 M3x16mm bolts (Allen head). Chances are the bolt holes are a hair too small for the bolts. Go through with a ~3mm drill bit till the bolt's a snug fit. On the bottom half, put a M3 bolt in from the build plate side (flat side) and thread the nut on it. Keep tightening the bolt until the nut gets pulled into the groove where the nut's supposed to sit. It's a snug fit. I'd recommend using some Heat reflective tape on the inside, and/or fiberglass heat wrap on the gas tube where it gets close to the handguard. DEI gold reflective tape works great. Do not print with PLA for obvious reasons... I chose to use PETG because it's strong, flexible, and is relatively heat resistant. If you have a CR10 or have a base plate limited to 300mm, print it diagonally (a^2 + b^2 = c^2 ftw)