Added sight rail and optional parts/upgrades to the STL folder

[R3DG0L1AD]

• v1.2a:
  • Added AP9 sight rail.
  • Added optional quad rail barrel retainer(replaces derwoods barrel retainer).
  • Added optional arm brace for 36mm buffer.
  • Added optional reinforced buffer tube and attachable M4 stock(replaces derwoods buffer tube).
  • Added optional improved mag release pivot retainer with 2 screw holes(replaces derwoods mag release pivot retainer).
  • Added optional foregrip for use with quad rail barrel retainer.
  • Added optional skeleton AR-15 grip.
  • Added optional skeleton foregrip.
  • Added optional 45 degree selector switch since the regular 90 degrees doesn't give much room.
  • Added derwoodvw's AP9 video build tutorial just in case it is purged. * Print with same settings as derwoods parts.
    • Rafts: Yes / Resolution: .15 / Infill: 100%
    • Added to maduce's fosscad-repo by R3DG0L1AD but most credit goes to thingiverse users Matt19888, m42quik, and idy26.

[T-Kyouko]

Non-AP9 specific files should probably go in their own folder. The 45-degree selector is already available but I have not seen the skeleton foregrip or pic. rail section.

[maduce]

These are great! What software did you cad these parts in? Can you add STEP files of each part and native file(s) as well, i.e., IPT, SLDPRT, F3D?