Oh yeah, it's all coming together.

Everything is fitted to the 1911-ish, so it's time to put it all together.  Because the mainspring housing is integral with the printed grip section, assembly is a bit fiddly.  It's not quire as straight forward as a standard 1911, but it's not too bad and it's not like it will have to come completely apart often.  I'll make a "how to assemble" post at some point.  I still need to reprint the grip safety in black too, I'll do that when I paint the frame.  Anyway, here's how it looks all together:

All that's left is to test it.  I got out my trusty "test stand", rope, and big tree to hide behind. 

Tube stakes

The last part that needs to be added to the 1911-ish frame is the plunger tube.  It's pretty simple, you put it in, then mushroom over the posts inside the magwell.  Before that can happen though, there needs to be someplace for the posts to mushroom into.  To do that, I took my dremel, and cutting carefully with the bit extending through the post holes, added a countersink to the back side.

They sell a tool to stake the posts over with, and it works very well.  I don't have that tool.  What I do have is a lot of random stuff laying around.  This little vice, for example, that I think I made in high school.  I took a setscrew and added a point to it to mushroom the posts.  I just hot glued the pointed setscrew onto the vice since it's a one time use tool. 

I used some green Loctite retaining compound on the posts, then staked them over.  The most important thing here is to find a perfectly sized drill bit to put into the plunger tube so that it won't collapse when you squeeze it.  Is this the worlds greatest tool?  No.  Did it get the job done?  Yes.

1911 feed ramp sanding jig

Here's a more detailed explanation of my 1911 feed ramp sanding jig.  It should work for all full size 45acp 1911s.  To use the jig, slide some 1/4" rod through the magwell so that it rests against the mainspring housing edge of the magwell, with the narrowest part of the jig on the feed ramp. Wrap the jig in sandpaper and sand away. Look at the cutaway pictures to make sure that you have the orientation right while sanding. Make sure that you DO NOT radius the top corner of the ramp, it must be a sharp corner for proper feeding. I shouldn't have to say this but DO NOT REMOVE ANY METAL FROM YOUR GUN UNLESS YOU KNOW WHAT YOU ARE DOING. Metal is easy to remove and hard to put back on. Oversanding the ramp can cause your gun to jam and become unreliable, and it will need to be repaired by a professional gunsmith.  Here's a link to the 3D printed bit: https://www.thingiverse.com/thing:4006165

Ramped up

This is one of those small but very important 1911 detail things, the feed ramp.  I chose to leave it completely uncut and in retrospect I should have just machined it along with everything else.  But there is a library's worth of discussion and argument on what the "best" feed ramp angle should be and I wasn't sure how the barrel would fit so I put it off until later.  And now it's later.  After a whole lot of reading, I decided that despite all the discussion and arguments, it is not, in fact, rocket science.  There are millions of these things out there from hundreds of companies, spanning over a century of manufacturing, and they can't all be the same.  I chose the most commonly recommended ramp, at 31.5°.  I started by laying out some guidelines where the limits of the ramp should be, the most important one is that it needs to be .030" from the throat of the barrel.

Not trusting myself to do an ultra precise angled setup on my little mill, I elected to do all the metal removal by hand.  I can already feel the gun community shudder as I start attacking this with my Dremel.

I may look stupid, but I'm not dumb, and I'm not doing all of it with the Dremel.  I'm just doing the roughest of roughing.  The rest of it will be done with sandpaper.  But how do you make a very precise angle with sandpaper?  With a happy coincidence and a stupidly simple tool.  You see, if you put a 1/4" rod through the magwell so that the back of it rests on the MSH side and the front lays on the feed ramp, it ends up being exactly 31.5­°.  If you then have a 7/16" diameter circle tangent to where it contacts the ramp, you have the exact diameter you need for the feed ramp.  I checked everything in Solidworks, and it all works out perfectly.  I made my tool with some 1/4" rod, and a 3D printed sleeve.  I put a center line on it so I could be sure it stays straight up and down while being used.

Wrap the sleeve in sandpaper, hold the frame in something secure, and have at it. I taped off as much as I could to keep from getting everything scuffed up.

I sanded using progressively fine sandpaper up to 400 grit, and stopped when I hit the barrel setback line I had scribed.

Then I hit it with some Mother's Mag and Aluminum polish to shiny it up.

I don't know how accurate it actually is, but it feeds very well with my dummy rounds.  We'll have to wait to see how it works with actual bullets.

Sliding on in.

Next up on my 1911-ish project is fitting the slide.  I machined the rails just a tiny bit oversized to leave room for hand fitting so that I could get the best possible fit between my frame and slide.  When I went to start fitting it though, I noticed something odd.  My frame rails were bent.  You can see the slight wave in the left rail here:

Weird, right?  Here's what I think happened.  When I clamped the frame in the vice for the last CNC op, the rails were facing down.  I can see witness marks from the vice showing where it was.  Here's where I had it clamped in the vice: 

I didn't think anything of it because there was solid aluminum in front of and behind the magwell and the vice wasn't actually touching the rails, so I really cranked down on it.  All I can figure is that the vice compressed the aluminum, but because there was no support at the magwell those areas just bent instead of squishing.  I'm not super concerned because it shouldn't really affect strength and some frames omit that portion of the rail entirely.

Anyway, fitting a slide is easy, but tedious.  File, check, file, check, repeat until it fits.  Instead of Dykem or some other layout fluid to see where the frame is making contact, I just use a black Sharpie.  Any spots that end up shiny get material removed.  You'll want to go slow and check frequently because it's easy to overcut and hard to fix if you do.  It probably only took me an hour or so to get my slide fitted and functioning right.  To my surprise the barrel needed virtually no fitting at all, just adding a very slight chamfer to the VIS area of the frame(which I'd purposely left out when I machined it).

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.