1911-ish

Even though my Uzi isn't done yet, and I have a thousand other projects going on at the moment, I decided to start another one.  Some time ago I made a complete 1911 pistol from scratch on the CNC.  On that one, the frame was made in two pieces, left and right halves, with some of the pins replaced with screws, as well as a few screws added in other places.  That made it very easy to machine in just a few setups.  It was mostly aluminum with 6061 for frame and 7075 for the slide, but it's just a 22lr so I wasn't really worried too much about strength.

I decided that I wanted to make one in 45acp though, as a proper 1911 should be.  I didn't want to do the left/right half thing again, not really trusting a bolted together frame in 45.  I could do it in steel and silver solder the halves together, but as mentioned several times in my Uzi build, I hate machining steel.  Making a complete one piece 1911 frame from any material involves a lot of odd setups and careful machining, and I am far too impatient for that.  The available 80% frames don't really hold much interest for me either, I like doing everything myself.  Fortunately, there's another way.

I'm going to be building this 1911 like the STI 2011 pistols.  It's going to use separate upper frame and grip sections.  I'll be using an off the shelf slide and Sarco parts kit for the hard parts, I'll CNC an upper frame from 7075 aluminum, and the grip section will be 3D printed.  I hope to have under $250 in the whole thing.  Here's the the CAD work I've got done so far.  All the important bits and anything that needs to be very precise is in the upper frame, and you can see how the upper and lower will be split:

I'm reasonably confident that a 3D printed grip section will be strong enough, all the real load bearing areas are in the upper frame.  The area around the front upper grip pin and trigger guard is much thicker than standard, and the sides of the mag well have a big rib going down them to add some extra strength to the print.  The only part I'm really concerned about is the pin that holds in the mainspring housing.  The pin hole area is thin to begin with, and I think it'll break on a printed part(that's the little hole on the bottom right of the grip frame in the pic).  Fortunately, I have a plan for that too.  I'm probably going to make the grips from aluminum.  The top grip screw attaches to the upper frame and the bottom goes into the lower, so I'll basically have metal supports running the full length of the grip frame.  I'm going to make the grips so that the mainspring housing pin goes through them too, giving it some extra support.

I'm going to try not to drag this project out too long...