Weld. JB Weld.

A lot has happened since my last update on this project.  I got all the parts fitted into my printed grip section, and then decided it didn't fit quite how I wanted.  Instead of more filing and fitting, I just changed the CAD file and reprinted it.  There are still some print artifacts in the latest one so I'm still not 100% happy with it, but it will do for now.

The next big holdup was the grip bushings.  The grip bushings on this particular gun are very important because they help in locating and locking the upper receiver and grip section together with the aluminum grip panels.  The grip bushings that came with my parts kit were cheap.  Very cheap.  The first time I screwed one into my freshly tapped frame I thought I stripped the threads out of the frame, but I tried a second one and it screwed in fine.  The first bushing was out of spec.  Given the importance of the bushings on this build, I decided I needed higher quality ones.  I bought THESE US made grip bushings and screws from e-bay seller "wvag".  They are really nicely made, and definitely worth the $7 that they cost.

Even with the nice bushings, I was concerned that the bushings would pull out of the plastic under recoil.  To lock the bushings into the plastic grip section, I chose JB Weld.  PLA+ filament doesn't get along well a lot of adhesives, but to my surprise JB Weld sticks to it very well.  So that's what I used to lock in the grip bushings, and fill in the gap between the bushing and the pocket to help support them for any side loads that they might see.

With the bushings locked in place, I felt comfortable putting the mainspring in and putting it all together.  Assembly is a bit fiddly because of the fixed mainspring housing, and I'll go through the assembly process in a future post.  There's still a lot of fitting and tweaking left to do, but so far it works pretty much how it's supposed to.