The Shallot - AR15 to AR9 Glock Magazine Adapter

!!!!!!!!!!!!!!!!!!!!!
This has only been tested in my particular frankenstein AR9.  Functionality and safety in any other firearm cannot be guaranteed.   If you damage your firearm or yourself, that's a you-problem.
!!!!!!!!!!!!!!!!!!!!!

v2b & v3 Update - long_tall_texan has converted my hacky STLs into step files and made a couple modifications.  v2b simply replaces the piece of filament hinge for the mag release lever with a M2x16 bolt.  v3 modifies the angle of the mag spring slightly so that it will "catch" harder.  I've not tried this version myself since v2 is working fine for me.  But if your mags aren't being securely retained, then v3 will likely help.

v2 Update - To try to add some much needed strength, I have added a horizontal upper support in the style of the sylvan arms adapter.  I have also added a hole through the rear tower through which a 60mm M4 bolt can be installed to add stiffness and strength.  The hex hole for the ejector bit has been ever so slightly shrunk to more securely hold the bit.  You may need to hammer the bit into place, but once there, it should stay put now.

I have about 200 rounds through the V2 version and so far it's working perfectly with no evidence of wear or deformation.

Print parts as provided.  Supports are needed, and I recommend slim tree supports.  You will likely need to clean up the support interfaces a bit for proper fitment.  Tolerances are tight all around, so be sure your printer is well calibrated.  Print with at least 6 walls and at least 60% infill.  Recommended to print at 0.16 layer height. Do not attempt to print with layer height greater than 0.2mm.  PLA+ is probably fine, but if you can print ABS/ASA, that's likely better.  It is strongly recommended to chase the mag catch spring insertion hole on the bottom with a 1/16" drill bit, or you’re going to have a hell of a time getting it in.  

Mag catch nubbin and mag release lever have hinges.  You can use a piece of filament for these.  The glock mag catch spring must be retained with a M2x10mm bolt.

The ¼” bit I’m using for the ejector is a Dewalt SL10 flathead, which is exactly 25.2mm tall.  If your ejector bit is even slightly different, you may need to make adjustments for that. 

Additional materials required:

Glock mag catch spring

M2x10mm bolt

Flathead bit (¼" hex shank) - Dewalt SL10 recommended.

Assembly instructions: 

Attach the mag catch nubbin to the lever using a a piece of filament.  Drop the glock mag catch spring into position from the hole in bottom.  Screw the M2 bole in from the side to retain the mag catch spring.  Finagle the lever assembly into position and retain it with a piece of filament cut to length.  Insert your flathead bit into the cavity in the top - it should be a fairly tight fit.

!!!!!!!!!!!!!!!!!!!!!
Test operation with snap caps before attempting to chamber live rounds.  
!!!!!!!!!!!!!!!!!!!!!