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Let’s 3D print a gun, Part 3

So you got a 3D Printer, and you went online and downloaded a 3D model of a gun. You upload it to the printer and hit print and a few hours later you have a gun, right?

No, there are a few more steps.

When you get a 3D printer, even if it is assembled, it needs to be calibrated. At a minimum the print surface (the bed) needs to be leveled to the print head.

The printer needs to be set to extrude the correct amount of material at a time, and the accuracy and precision can be adjusted.

I usually use my 3D printer to make decorate objects or toys, which are not precision parts. So I didn’t worry about much about those tweaks on my Tevo Tornado. Back when I had a Tevo Tarantula I spent countless time trying to improve performance and never really got it where I wanted it.

PLA filament goes bad when exposed to humidity. I live in Florida. You might realize what the problem is. While spools of filament are vacuum sealed, once opened they have a limited useful life span.

Various brands of printer filament may use different formulas, so you will likely need different print settings for different brands of filament. Even worse, you might need different settings for different color filament.

Running the printer at different temperatures also drastically affects the print quality. Ideally, when ever you switch filaments you would print a “temperature tower” which is a single print that is done at various temperatures so you can see what temperature provided the best qualities, usually focusing on layer adhesion.


Ugh, that is a whole lotta work. Screw it, I’m gonna skip all those steps.


One more important/boring bit of how 3D Printers work:

People use 3D modeling or Computer Aided Drafting & Design software to make 3D models of parts. Popular options for mechanical design include Solidworks, SolidEdge, Alibre, Fusion360, ProE, Creo, etc.

This software is used to make a 3D model which is then usually saved/exported into the .STL format, which is most commonly used in 3D printing.

A STL file has the data of what the model is, but omit details like scale or tolerances.

Then we have “Slicer” software. In CNC machining, we tell a machine to move along the various axis and make cuts, drill holes, etc. The code to do this is called “G Code”. Simple programs can be written by hand, more complex projects may use Computer Aided Machining (CAM) software to generate the G Code necessary to machine the part.

Slicer software takes that 3D model from the STL file and slices it into thin horizontal slices, then generates G Code to tell the 3D printer what movements it needs to make to print out that part.

When I ran a FADAL CNC Mill, our programs often had a few hundred lines of G Code. When I run my 3D printer, a print might require a few hundred thousand lines of G Code. No one would be writing a program like that by hand.


A render of the 3D printable “Liberator” pistol design.

I had initially planned to print a single shot .22 that would be mostly plastic. Figured it might survive a round or two.

Hopefully.

BUT, and a bit one at that, there is this law on the books about “untraceable firearms”.

The United States Undetectable Firearms Act of 1988 (18 U.S.C. § 922(p)) makes it illegal to manufacture, import, sell, ship, deliver, possess, transfer, or receive any firearm that is not as detectable by walk-through metal detection as a security exemplar containing 3.7 oz (105 g) of steel, or any firearm with major components that do not generate an accurate image before standard airport imaging technology.[1]

https://en.wikipedia.org/wiki/Undetectable_Firearms_Act

This law, like most of our stupid laws, came about because of stupid reasons. Idiots out there thought that these new and ultra evil Glock pistols could slip right though metal detectors.

Thus, while we COULD print an almost entirely plastic pistol, it would be illegal.


I’ve learned that some people have modified the “Liberator” design to accept a steel block epoxied (permanently) into the frame.

When I started this project I intended to print the “Gluty V0.2A” 9mm pistol. It is similar to a 9mm AR15, but uses a heavily reinforced printer upper and a Glock barrel.

The “Shuty” was the first 3D printed firearm I found interesting.

Picture of the Shuty pistol, found online.

The Shuty was designed somewhat like a 9mm AR15, but used a 3d printed mag and a Glock barrel. The Gluty was an upgraded Shuty that used Glock magazines.

There is a newer version of the design called the “FCG-9” which is designed to use as many 3D printed parts as possible so that people who do not have firearm parts available to them could build it. It still uses an AR15 fire control group, but it no longer uses a Glock barrel.

FCG-9 Picture from the internet.

I hadn’t used my 3D printer in some months. The better part of a year it just sat around getting dusty. I had a new sealed package of cheap PLA+ filament. So I decided I would throw that in the printer, dust off the print bed (I use an Ikea mirror for a smooth flat surface), and start printing.

Smart thing would have been to calibrate and tweak the printer for the filament. But what fun would that have been.

The Gluty lower took about 27 hours to print, if I recall correctly. As I said in a previous post, 3D printing can not print a cantilevered structure. If you would to try and print a T shaped object, the top of the T would collapse during the print and it would fail. So you would either print the T shaped object upside down, or use supporting material to provide a scaffolding to the part.

There are many different ways to set up the support material. As I have previously done very little printing with support material, I used the default settings. This was probably a mistake.

Hours and hours later of using a scraper, plyers, side cutters, I was left with lots of support material still in the lower.

While working on the lower, I went ahead and printed the upper.

It came off the printer looking like this:

I spent many more hours removing support material.

Finally, it was starting to look like something that might actually work.

So I went and read the instructions on how to make the Gluty pistol.

Turns out it requires a little more metalworking than I am set up to do in my little hovel of a home.


I could have continued with the Gluty project, but I was starting to run low on filament, and the monitor on my laptop (Surface Pro 2017), which I use to run my 3D printer, started to fail. I decided it was time to shelve this project and go in a different route.

I looked at a variety of AR15 lower designs that are printable. Picked one that seemed decent to me and printed it out. Since then, I have assembled it, and am about to take it to the range for test firing. We will go over that next time. I’ll also go into more detail about the Gluty design.

Let’s 3D Print a gun – Part 1

Let us skip with the intro and get to the printing. Plenty of time to chat about details later in other parts.

After about 27 hours on the 3D printer, this block was pulled off the print bed:

I spent two hours today removing support material with some side cutters, a couple of pliers, and a scraper. It is starting to look more like the finished product, but there is still a long ways to go.

3D Printers add material in layers to build up an item. So you could print something shaped like the letter V with no problems because the layers support each other and you can have some amount of overhang of a previous layer. But a shape like the letter T would fail because it would be trying to print the top line of it in the air and the print would fail. To solve this problem we can add supports, additional material to provide a base for the final product to print on. Unfortunately, like in this case, those supports can be a pain in the ass to remove.

There is a still a large amount of support material in the mag well, and in the various holes in this trigger housing. It is going to take me a good while longer to get it cleaned up.

I’m not sure if I am going to try and finish this part first, or start working on the next. I’ll give you all some proper details and explanations later. But for now, I am really impressed with how rigid this part feels. The additional material along the top sides makes it feel far more rugged that some of the old cheap plastic AR15 lowers I have handled.

“Absolute disaster shooting my new 9 mm upper “

B-ARFCOM user Johhnyrotten had a really bad day with his budget upper bought from Midway.

Report
Midway recently had an exceptionally good price on an AR Stoner 9 mmm upper that I bought. I went the range today to shoot it for the first time. I put it on my PSA 9 mmm billet lower that has functioned perfectly for thousands of rounds
  The initial shots proved it to be single shot. It would pick up a new round from the magazine but it would not reset the trigger. I figured it just needed to be broken in so I shot 20 rounds that were individually in the magazine.  I then tried a mag with 2 rounds to see if functionality had improved.
 There was a small explosion. The gun had doubled and there had been an out of battery detonation.
 There was intense pain my forearm.  I looked and the cartridge had penetrated my skin and punctured a vein with what appears to be the case head. Blood was pouring out like water out of a faucet. Having a medical background,  I new to apply direct pressure.  While I was sitting down applying pressure I noticed a steady stream of blood accumulating in my lap. The other had cut my chin.  So had to apply pressure with both hands

 

Ouchie.

Read the thread below.

https://www.ar15.com/forums/General/Absolute-disaster-shooting-my-new-9-mm-upper/5-2352705/#top

Thoughts from the range

Went to the range yesterday, shot my B&T APC9K with the Glock lower for the first time. Also shot a SCAR with silencer. Got to get some quality time behind the Trijicon MRO green dot optic.

I really like the Glock magwell lower for the APC9K. I bought the gun with the intent to get that and while I don’t like how long I had to wait, it was worth it. The mag release and bolt catch are also easier to use on the Glock lower than the standard B&T lower.

I remember when the Trijicon MRO came out I read some early reviews and looked at the price tag and pass on it. There didn’t seem to be any reason to pick one over an Aimpoint. I didn’t even know Trijicon had come out with a green dot model like this one. Apparently they have announced a new model with an Eotech like reticle (MSRP somewhere in the $900ish). That is two options that Aimpoint does not have.

The MRO has fractionally more magnification than an Aimpoint and it is noticeable. All lenses will distort light to some amount. I’ve read that Aimpoint lenses are something like 1.03X and the MRO something like 1.05X. Seems like a trivially small difference but it feels very different looking though the optic.

Indoors when I first looked though the MRO, I thought that extra tiny bit of magnification was extremely noticeable and distraction and I thought that the optic was garbage. But using it out doors, live fire, I found it just fine to use. Felt weird having uncovered adjustments on the MRO, but they worked fine. It is plenty bright and worked fine.

While the MRO is small, it feels a good bit bigger than an Aimpoint T-1. On a small gun, I would always pick the T-1. Well, hell, I’d ALWAYS pick the Aimpoint over the MRO. But I think the MRO would feel fine on a normal or larger gun.

The MRO seemed perfectly serviceable, but I wouldn’t pick one over an Aimpoint unless I needed that green dot or circle dot reticle.

I think I’ll write about the SCAR at a later date. I was rather disappointed with it.

Ugh, I hate rust.

Left some of my cheap practical steel cased ammo in the truck of my car. Went to do some training today and found it was rusty.

I decided I was going to go ahead and use it, perhaps get the chance to practice my malfunction drills. I found that the B&T APC9K ate up this rusty ammo with no complaints. Only had one failure to fire on the Sig M17.

Really goes to show the value of proper ammo storage.