Sunday, July 28, 2019

I'll keep this brief

I need a case for the Uzi.  Most normal people would just go out and get a normal gun case.  I am not normal(which I will freely admit to anyone who asks).  Since this is a Uzi, I decided it needed more than a plain, boring gun case.  Back when the Secret Service used Uzis, they carried them in briefcases, so I decided that mine should have a briefcase too.  $25 later on e-bay, and I had myself a nice, used briefcase.  It's not a quickly deployable hardshell Samsonite like the SS used, but I like the leather look better(and I shouldn't have to say this, but just to be clear it is NOT an operational briefcase, just a storage case).  For padding, I used Harbor Freight foam floor mats.  Since thick EVA foam like this is a pain to cut with a blade, I used my electric turkey carving knife.  It made quick work of things.  It's made to securely hold the gun, two mags, the barrel and shroud, and a mag loader that I 3D printed.

Ordinary looking nondescript briefcase:
Uzi all safe and secure inside:


Done and done.

Well, I got my Uzi done.  After baking, I hit everything very lightly with 0000 steel wool to make it slightly less flat and feel a bit smoother, then soaked it in CLP.  I way over oiled it so the CLP could soak in between all the spot welded sheetmetal bits. The only new piece that I haven't shown before is the barrel shroud.  I don't like the anteater look that the bare 16" barrels have, and fake suppressors aren't my thing, so a US Barrel Shrouds vented barrel shroud was just the ticket.  It's a very nicely made part and it simply replaces the barrel nut on the front of the receiver.  Since I built this as a "pistol" receiver, if I ever get a 10.5" barrel for it I can remove the stock and use the original barrel nut for the short barrel. Anyway, here it is set up as a carbine.


I used Testors model paint for the safety selector.  Because the black Gun Kote is very solvent resistant, I could paint the red and white in kind of sloppy, then use a paper towel damp with mineral spirits to wipe off the excess.  Since the safety selector won't go all the way forward, I just left the FA lettering black.

The color is a bit off in the other pics because of the lighting, but this one is a pretty accurate representation of it's true color.


Saturday, July 27, 2019

I need a new filing system.

Less words, more pictures this time.  Every custom 1911 build needs a lot of hand fitting to make it all work, and this one is certainly no exception.  This one will probably take more than most, partly because I left extra stock in a few spots so that I could hand fit critical areas, partly because my Sarco parts kit doesn't include the wold's highest quality parts, and mostly because of how I chose to machine it.  Most of the finish work was done with a 1/8" ball end mill because my smaller end mills have limited reach.  This left me with radiused corners in areas where there shouldn't be radii.  So, out come the files...

Also, I learned that if you take very close up pictures of small objects, machine marks tend to look terrible when blown up to full screen.  Anyway, the first place to get attention was the mag well.   I got what I could with a 1/16" end mill, but had to finish most of it with the 1/8", so I had to file the corners out to get magazine to slide freely.
The next bit to fit was the safety lever.  It was very close to dropping right in, but not quite.  This time, I removed material from the back side of the safety.  Given a choice, it's always better to remove material from an easily replaceable part instead of something hard to replace like the frame.
Then I had to make the hammer and sear fit.  Miraculously, the pin holes lined up, but like the magazine, these parts didn't fit because of the radius left in the corners.  It's an awkward spot to file with standard shaped files, so I used my riffler files.  If you don't have a set of riffler files, you should get one.  They're like needle files, but with curved tips that make areas like this much easier to get into.
Next up is the ejector.  It was very close to fitting too, but not quite.  There were burrs on the ejector legs and I probably could have pressed it in, but it never would have come out again.  Some light cleanup is all it took to get it it fit.
Another handy tip for when you have to work on small parts.  Get yourself a ring clamp.  They're cheap and they're great for holding small things securely while you work on them.
On to the grip section.  I printed my "final" version in black, using 100% infill and a .08mm(.003") layer height.  It didn't take much fitting at all to get the parts in.  The one problem I did have is that the trigger bow it's self was to narrow for the magazine to slide through(did I mention that these are all pretty cheap parts?).  I tweaked it out just lightly and now everything works like it should.
With that done, I could test fit all the bits I have fitted so far.
I can't decide what pattern I want for my grips get, so I printed a temporary blank set for now.  Eventually they'll be made from aluminum to hold the upper and lower sections together.  I also decided that I'd run with this 3D printed thing a bit more and use it for the grip safety too.  I found a file online for a beavertail safety and printed it out.  The file isn't perfect and I'll have to rework it a bit so that it functions the way it should, but this one works as a proof of concept.



Friday, July 26, 2019

A Gripping Development

The last piece of the Uzi puzzle is the grips.  All of the grips that came with my parts kit were pretty beat up, and I didn't want to put well used grips on my practically new gun.  You'll remember a while back, I 3D scanned and printed the front grips because I couldn't find new ones for a price I wanted to pay.  After a few more tweaks I reprinted them in black to use as my final parts.  I also hit them with scotch-brite to knock just a little bit of the shine off. I'm still not completely satisfied with the right grip and may rescan and reprint when I have the time/motivation.

The pistol grips are a different matter though, and are easy to find.  I got a pair of genuine IMI grips still in the package from 1965.  According to the tag, these were from the German market.  I still find it incredibly ironic that the Germans of all people adopted a Jewish weapon for their defense forced.

Sunday, July 21, 2019

The most exciting thing to happen in a long time...

It's a very exciting day here in Jeff's basement.  This day has been a long time coming, and days like this don't happen often.  What's so special about this day you ask?  Well, I'll tell you.  It's new cardboard on the workbench day!  Every now and then, the old cardboard gets dirty and chewed up enough that it needs to be replaced, and that day is today.  Oh, and I finished machining my 1911-ish upper frame too.

These are very tedious guns to machine in general, and especially so on a mill without a tool changer.  Practically every hole on the thing is a different size so there are a lot of tools needed for single operations.  The first operation from my last post was from the top down.  The second operation was all the machining on the right side.  I chose to leave as much of the bottom solid as I could to help keep as much rigidity in the part as I could.  The boss that I left on the front of the dust cover gives that thin area a bit more support while machining, and gives the vice something solid to clamp against.
The third operation was all the features that needed to be done on the left side, and it's really starting to look like something now.
Just one setup left, machining all the extra material off the bottom.  I made the dust cover extra long so that I can cut the boss off the front, and trim the dust cover to match my slide just how I want it.  Anyway straight to the money shots: 





Saturday, July 20, 2019

Work that body

This gonna be a long post, so I hope you're not busy.  It's time to actually finish my Uzi and get it painted.  I always dislike this part because I'm a bit of a perfectionist when it comes to painting.  Comes from spending years in the car hobby.  Nothing irks me more than spending a lot of time and effort on something, then ruining it with a crappy paint job.  Now, on to the Uzi.  My welds are good but not cosmetically perfect, and in a couple spots I wasn't as careful as I should have been with the grinder.  Add in the machining marks from my machined center section, and there's no way I could just slap some paint on it without it looking terrible.

First everything was thoroughly degreased using Brake Cleaner.  Brake cleaner specifically, because it won't leave a residue of any sort on the parts.  Do Not use Carburetor cleaner, some brands leave a residue that could affect your paint.  From this point forward, everything should be done with gloves on.  The oils from your skin can ruin the finish.  Nothing worse than laying down your paint, only to have a fingerprint show up.  After degreasing and drying, I stared attacking it with sandpaper.  I used my Harbor Freight oscillating multi-tool, the triangle shaped sanding pads work great for getting into corners.  After a thorough sanding with 120 grit paper, here's what I ended up with:
You can clearly see some weld edges and the gouge I managed to put it while grinding by not paying enough attention/being in a hurry.  After knocking down the high spots, I sandblasted the whole thing in preparation for the next step.  I needed to both fill in the gouges, as well as make the whole thing actually flat so it doesn't look all wavy when painted.  Bondo is great for cars, but it's too soft for guns, and in addition, the paint I'm going to use requires baking at 325° to cure and bondo won't handle that much heat.  Instead we're going to use JB Weld.  JB Weld works perfect as a high temp filler for this kind of thing.  It's tough but slightly flexible, it sands easy, once cured it's impervious to just about everything, and it will hold up up to 500°F.  I mixed some up and and spread it on in the places where it was needed.  Try not to put too much on, remember that most of what you put on will be sanded off.
Once cured, I blocksanded the JB weld down with 80 to knock down the high spots, then 180 grit sandpaper to finish.  It's important to use a sanding block or rigid backer when doing this, sanding with just your hands will lead to a wavy surface.  A rigid block will assure that it actually ends up flat.  I use a combination of sanding blocks and popsicle sticks with sticky backed sandpaper.  Since the JB Weld is softer than the steel, you also want to make sure you don't oversand it.  Oversanding will leave low spots and waves just like hand sanding will because the JB Weld sands faster than the steel.  Here you can see how it looks ones it's been blocksanded.  The low spots are pretty obvious.
When working on cars, a sandable primer surfacer is the next step, but that obviously won't work here because of the temp required to cure the paint.  Fortunately, the paint it's self can serve as the primer.  I used Duracoat on my AK and it worked well, but because it's a 2-part urethane you have to mix it then use what you mixed and clean all your equipment before it sets.  On my last few projects I have used KG Gun Kote.  In my opinion it's easier to use and more forgiving than Duracoat.  It's very easy to apply, cures to a very tough finish, and most importantly for our purposes, sticks to it's self very well.  It's always important to do a test piece first, and here's why.  I got a bottle of the KG Satin Black thinking that's what I wanted, but when I did my test piece, it ended up way too shiny for my liking.  No matter how I sprayed it, it always ended up too shiny, much more gloss than satin.  So I got a bottle of their Flat Black, and it was just about perfect for what I wanted.

That left me with a full bottle of Satin.  So I decided to use it as my primer.  As I mentioned above, KG Gun Kote sticks to it's self very well meaning I could spray it on, bake it, sand it off, and recoat it without having any adhesion problems.  And that's exactly what I did.  Since the satin ended up so shiny, I also decided to use it to paint the insides of all the parts so that they would be a bit slicker, and easier to clean.  The inside of the receiver, top cover, and grip section all got coated, as well as the outside of the receiver over the JB Welded areas.  It's slightly oversanded so it's very easy to see where the JB Weld is under the paint.  If you're really careful with your sanding, you can skip this intermediate step and go straight to final paint, but knowing that I was going to do it anyway, I wasn't too worried about it.
I sprayed the Gun Kote on thicker than recommended too because I wanted to make sure that it filled it what it needed to, and most of it was going to get sanded off anyway.  Try not to paint anything you don't have to though, any paint that you intend to paint over will need to be sanded or scuffed up for the next coat to stick.  Turns out Gun Kote sands really well too and makes a great primer.  I blocksanded it with 320 grit paper to make sure that I didn't get any sand scratches showing in the final paint.  Being the top notch planner that I am, I didn't take a picture of this same side of the receiver after sanding, so here's a pic of the other side.  You can still see about how it should look with all the low spots filled.
With that bit done, it was time for final paint.  After another very very through degreasing, I whipped out my trusty $10 Harbor Freight paint gun and had at it.  One of the things I really, really like about the Gun Kote is that it goes on thin and air dries very quickly.  Normally when I paint things, I have to carefully hang each piece so that I can cover the whole thing, but that's really tedious when you have a bunch of small pieces like this.  Because the Gun Kote dries so quickly, I could paint the back sides, let it dry, flip everything over and paint the tops all in an afternoon.  It's also handy for things that have to move like the folding stock.  I could paint it in one position, then unfold it and hit the spots that were missed.
Gun Kote sprays really, really well straight out of the bottle.  It's very easy to get nice, even coats on your parts.  It dries so fast that getting dust in the finish isn't really an issue.  If you screw it up and get a run or something and need to try it again, unbaked Gun Kote wipes off very easily with most solvents like lacquer thinner or acetone.  For reference, I used about 3/4 of a 4oz bottle to put 2-3 coats on all my Uzi parts.  Once you're happy with how it looks, into the oven it goes.  I live by myself with no one to give me any dirty looks, so I just used my kitchen oven.  It should be noted when placing your parts for baking that anyplace that is touching something will end up with a slight shiny spot, so try to set things on surfaces that won't show once everything is assembled.  Bake for an hour at 325°F, pull it out to cool, and here's what we ended up with.  Mmm...freshly baked Uzi...

So how'd we do at making this thing flat?  Not perfect, but I'd say pretty darn good.




Friday, July 12, 2019

Salsa for these chips

As you know if you're been following along with my other posts, I hate machining steel, so for my 1911-ish project I'm going to make the upper frame from 7075 aluminum.  If you're not familiar with 7075, it is in many respects as strong as some steels, but without the weight or hassle of machining.  The only real downsides to 7075 are it's cost, it's pretty expensive compared to other alloys, and the fact that you can't weld it, which hopefully I'll never have to do.  For stuff like this where I only need a little bit, e-bay is my go to source.  You can often find cutoffs from a wide variety of materials at very good prices.

Unlike my Uzi bolt, this piece is going to require actual precision. The Uzi bolt really only has one critical dimension, the headspace distance.  Everything else can be +/- a bit and will still work fine.  This thing requires actually holding a tolerance, so lets hope it turns out.

My workspace isn't overly well contained, so stuff like this is an exciting game of machine for a while, vacuum the chips, machine for a while, vacuum the chips, repeat.  Even though it's just aluminum, I'm still using carbide tooling too because carbide is so cheap these days that there's no reason not to.  I have my coolant/air blower set up as a homemade Fogbuster style system, so it's just mists on the coolant without making a huge mess of things.

Off to a good start, here's how my first setup turned out:

Wednesday, July 3, 2019

1911-ish progress

So I had me an idea.  One sticky point on my 1911-ish build is that I'm concerned that the mainspring housing pin hole area is pretty thin, and that on a printed lower it will break out and let the mainspring housing go flying.  So then I thought what if I just make the mainspring housing one piece with the grip frame?  That would give me some extra strength in the grip frame, and eliminate the worry about the MSH retainer pin breaking out.  The biggest problem I see with that is that the sear spring has to go on before the MSH, and the MSH keeps the sear spring tab locked in it's slot.  To get around that, I'd add some extra clearance so that I could slide the sear spring in from the top, and once it's tab is in the slot in the mag well, I'd put a pin through the grip frame so that the spring couldn't come out of the slot.  That extra pin would be captured by the grip panels.  Hopefully that makes sense.  Here's a few pics that hopefully will explain it a little better.

Looking from the back of the grip frame, the red pin fills the gap between the sear spring and the now merged MSH/frame, keeping the sear spring in place:

Looking from the front:




Nothing is as good as actually being able to look at the thing, so I fired up the old magic machine and printed some parts.   I printed one with the standard MSH layout, and one with an integrated MSH.  While I was at it, I printed a temporary frame to make sure everything fits together like I want.
The integrated MSH seems to work alright.  It's a bit of a hassle to assemble, but really, once it's together it'll rarely have to come apart.  I put it all together with my slide and barrel, and all the internal parts of the grip frame are assembled.  The yellow printed temp frame isn't really strong enough to hold any spring pressure so all the FCG parts except the trigger and sear spring were left out.  The pin through the grip frame retains the sear spring perfectly.

Tuesday, July 2, 2019

Starting to finish

I'm at that point where I actually need to finish my Uzi.  I'm going to start with the bolt, because it's the easiest thing to finish.  As much as I like the machined look, this is an Uzi, and Uzi parts shouldn't be bright and shiny.  I could have all my parts parkerized like the originals, but I don't want to deal with shipping and the cost.  Fortunately, there is another way(and it's really easy).

For the bolt, I'm going to use Precision Tool Black( https://precisionbrand.com/product-category/tool-black/ ).  It's a blackening compound for ferrous metals, and it's super easy to use.  Just wet the metal with it, and almost instantly it turns black.  Here's the bolt, about half way covered(picture taken with my potato camera in poor lighting by the sink).
The Tool Black can't compete with industrial black oxide coatings for durability and you'll still need to keep things oiled to prevent rust, but it also doesn't require any special equipment and it goes on at room temperature.  It's literally wipe on, wait a few seconds, and rinse off with water.  I generally use a chunk of scotch-brite pad as an applicator, though you can just dunk your parts in it too.  A little goes a long way, and you could get several whole guns out of a pint bottle.  After coating the parts, a brownish-black film develops that I buff off with dry paper towels.  The rougher the surface, the blacker it gets so sandblasted parts come out very black, and polished/smooth parts tend to be a very dark gray.  Here's how my bolt looked after being treated: