Here we have the Gluty AR-15 9mm Pistol and it works. This firearm is the colloration of 3 designers over the course of a few months. It accepts a Glock generation 3 or 4 magazine. This design is an improvement on the FOSSCAD Shuty AR-15 9mm Pistol version 4.0 MP-1. The Gluty uses all the same parts as the Shuty v4.0 MP-1 except for the lower receiver and magazine release.
All parts were printed and tested with Atomic PLA filament except for the ejector which was printed with Atomic Super Impact PLA. You can use ABS but i cannot guarantee a proper fit and parts could possibly fail due to bad layer bonding if done incorrectly; be advised.
* Gluty Lower - print vertical with buffer tower on the build plate.
* Bolt housing - Print vertical with hammer end on the build plate.
* MP-1 Upper - Print vertical with barrel end on the build plate.
All other parts should be self explanitory.
##### Machine settings PLA
* Bed 50
* Nozzle .4 temp 220
* extrusion width .45
* cooling fan set to 40% starting on the second layer
* layer height .15
* filament diameter set to 1.71mm
* Infill 100%
#### Assembly Instructions
##### Upper Receiver
After you print the upper you need to drill out the four barrel retainer holes with a 7/64 drill bit to a depth of 23mm. When you attach the barrel adapter the machine screws will be difficult to insert. Take your time and you will have to back the screws out every so often as if it were a tap. Also the two endcap holes at the rear of the upper need to be drilled out with a 7/64 drill bit.
Insert the two 154mm 1/4" dowels into the upper, these reduce bolt friction and also reinforce the upper. They should go in fairly easy and apply oil to them before inserting. You will notice two small pilot holes close together on the ejector side of the upper, these are for the ejector pivot drill them uot with a 1/8 bit. You will only be using one of the two holes, I use the rear most hole but you may want to experiment. Be careful when installing the ejector pivot screw, screw it in a little at a time and back it out each time so that it does not crack the upper. Drill out the front takedown pin hole with a 1/4" drill bit.
Insert the barrel into the upper using a 12-16" wood 2x4 block. you will have to pound it in slowly being careful to make sure its not too tight and possibly crack the upper. My barrel goes in fairly easy but some printers may print the hole too small and filing will be required. When the barrel is fully inserted it should protrude slightly into the upper so that the face of the bolt bumps the barrel before it bumps the plastic upper. Once the barrel is installed slide the barrel retainer over the barrel and insert the screws, make sure the retainer seats completely against the upper. If there is a gap the barrel needs to be driven in a little more.
##### Bolt and Housing
The housing should fit into the upper without any sanding but you will want to sand the flat sides of the bolt housing and the two bottom rails so that they are smooth.
Start with a 43.9mm steel dowel approximately 55mm long. You can cut the final length later. Use the printed jig to mark the bolt for the cut out. Using a hand held grinder with a thin cutting disc, cut the notch out of the bolt. Once the notch is cut insert the bolt into the housing mark and cut it to the correct length.
Wedge the bolt into the housing so that it can't move inside the housing. Wedge it with a tooth pick between the top of the bolt and housing. do not wedge it at the bottom or sides because you want the bottom of the bolt to be resting on the housing when marking the firing pin hole and spring guide hole.
Mark the firing pin hole using the firing pin hole in the rear of the housing.
Insert the bolt and housing into the upper being careful not to let the bolt move inside the housing. Once the bolt bumps the barrel use a large diameter pencil to slide into the barrel to mark the firing pin exit hole. Also mark the spring guide hole at the rear of the housing.
Using a drill press drill the firing pin hole from each of the ends meeting in the middle use a 9/64 drill bit. Drill the spring guide hole with a 5/16 drill bit. Counter sink the rear of the spring guide hole with a 1/2 drill bit to a depth of 12mm. Once the bolt is drilled, drill out the firing pin hole in the housing with a 1/4" drill bit. Clean off any burrs on the inside so that the bolt can completely bump the rear of the housing. Finish drilling out the spring guide hole in the housing with a 1/2" drill bit. Clean off the burrs on the inside.
Make sure that the firing pin slides smoothly in the bolt and housing before using epoxy. Apply two part epoxy to the bolt and inside of housing, do not apply epoxy to the lower most portion of the bolt housing the epoxy will get pushed into the firing pin hole. Make sure the bolt is centered in the housing before the epoxy sets.
Once the epoxy sets insert the firing pin and spring and use a 7/64 drill bit 27mm long as the retaining pin. Use the smooth part of the bit. Insert the bolt into the upper and mark the hole for the charging handle. Mark the hole as far forward a possible but leave at least 3/16" so that the handle does not bottom out before the bolt closes.
Drill and tap the hole for 8-32 all thread the plastic knob onto the all thread.
Insert the bolt into the upper and screw the handle into the bolt.
Use a good gun oil on the bolt housing and interior of the upper. Make sure you oil the bottom of the bolt housing.
Insert the 180mm 1/4" dowel into the bolt and upper and then insert the main spring. If you cant find a spring long enough it is ok to use two pieces, just make sure that the factory ends face each other.
Install the end cap using the listed screws and the upper is complete.
Attach the upper to the Gluty lower using a 1/4" steel dowel 44mm long (front take down pin) and a 6-32 machine screw for the rear pin. The screw will thread into the upper and lower.
Insert the buffer spring into the buffer bolt, Make sure that the spring can compress freely into the bolt. You may have to ream the hole some. If the spring is a little loose then wrap some tape around the bottom end so that it stays in. Make sure that the factory end of the spring faces the bolt.
Thread the buffer bolt into the buffer tower. Done!
##### Lower Receiver
As with all printed AR lowers you will have to drill out all of the holes for the FCG, safety selector and safety selector locking pin. You will also have to tap the lower for the grip bolt.
In order for the lower to function correctly you will have to cut off one of the hammer spring legs(cut off 18.5mm).
Drill the front take down pin holes with a 1/4" drill bit.
Install the mag lock arm and pivot, make sure it works smooth and use the pivot screw hole as a template to drill a 1/8" hole into the mag well. Make sure the screw does not protrude into the mag well.
Install the mag release shaft with the mapointed side facing the mag lock arm and also install the spring before screwing the arm and pivot into place. Install the feed ramp into the lower at the top of the mag well.
Disclaimer: Use these files and instructions at your own risk. These files are for educational use only.
If you have any questions please do not hesitate to chat with us. We are active in IRC on OFTC in #fosscad and on twitter @fosscad. Visit http://fosscad.org/fc/chat/ for more details.
