Bolt Together AR-15 Castle Nut

thingiverse

This is for the AR-15_Bolt_Lower_Receiver_v2.0-RollTroll from the FOSSCAD_MEGA_PACK_v4.8_(Ishikawa). Once I assembled my rifle I noticed that the castle nut included with my kit would not work with the 3d printed lower due to the buffer tower on the lower being way to thick. To remedy this, I made my own out of ABS. You will need at least two 8-32x1/2" screws; five is preferred, and two 2-56x1/2" screws. You must acetone dip (not vapor, but an actual dunk in acetone) to increase strength, otherwise the part will split! Acetone dip for 30 seconds, then heat with a hot airgun until the part is no longer tacky. Dry the part for 1 hour, then tap the 8-32 threads. The 8-32 screws hold this plastic "nut" in place on the buffer tube. The 2-56 screws are driven into the recessed holes into the rear of the buffer tower on your lower to prevent the "nut" from rotating. The "nut" is going to be a tight fit when inserting over your buffer tube, keep this mind if your filament shrinks and scale accordingly.