3D Printing Chassis?

[ecestu]

Just doing a little spitballing here on a sleepless night, but with the popularity of 3d printed guns and accessories, I had an idea. Would it be possible to print a chassis for your registered receiver, cut the magwell grip off, and use whatever magazine you wanted? The 3d print would dictate the bullet angle/magazine height, so the upper would stay OEM. I was browsing Fosscad reddit, and came across the below link on the "Smack-11" that got the wheels a-turning.
https://www.reddit.com/r/fosscad/comments/rq3bjt/smack_11_up_and_running/

 

[Tinman45]

Possible to do anything you want. If you’re just doing it to your own piece, the ATF probably doesn’t care. Might make it impossible to transfer and one less piece on the registry when they become aware. If you’re talking about developing a product for market, seeking ATF approval, some posters here can probably give you some cautionary tales.

 

[strobro32]

Yes. You could cut the grip off the lower, make a chassis to hold the lower and upper and use what ever mags you could make fit.

The gun in your link would probably be considered a SBR.

The SBR in the pic uses a AR15 fire control group. It would need a semi bolt and upper to work with that FCG.

An select fire M11 or open bolt upper can not use a AR15 FCG but a shell could be done. We discussed the shell idea when the SRU bull pump kit came out. The SRU kit does not require cutting the grip off.

I personally would not use 3D printed parts for a finished gun as the material breaks and melts too quickly.

 

[Galil#1]

No.

This makes perfect sense:

"personally would not use 3D printed parts for a finished gun as the material breaks and melts too quickly."

Now... Can a 3D printed part, be "printed around" like a steel subframe/chassis? Too complex/PIA?

 

[Gaujo]

Just doing a little spitballing here on a sleepless night, but with the popularity of 3d printed guns and accessories, I had an idea. Would it be possible to print a chassis for your registered receiver, cut the magwell grip off, and use whatever magazine you wanted? The 3d print would dictate the bullet angle/magazine height, so the upper would stay OEM. I was browsing Fosscad reddit, and came across the below link on the "Smack-11" that got the wheels a-turning.
https://www.reddit.com/r/fosscad/comments/rq3bjt/smack_11_up_and_running/

I just don't know how you'd make the FCG work.

 

[ecestu]

No.

This makes perfect sense:

"personally would not use 3D printed parts for a finished gun as the material breaks and melts too quickly."

Now... Can a 3D printed part, be "printed around" like a steel subframe/chassis? Too complex/PIA?

That's my train of thought. Doesn't seem like it would be too complicated. Maybe create an extended selector. Cut the magwell and trigger guard off. Maybe have an extended trigger, like a few mm longer. Stock choices are endless.

 

[ecestu]

I just don't know how you'd make the FCG work.

Not trying to make the AR15 FCG work. Just want the Glock (or whatever) magwell/grip.

 

[ecestu]

Possible to do anything you want. If you’re just doing it to your own piece, the ATF probably doesn’t care. Might make it impossible to transfer and one less piece on the registry when they become aware. If you’re talking about developing a product for market, seeking ATF approval, some posters here can probably give you some cautionary tales.

Lol. I don't care about the market. If I developed anything, I would drop the files to the public.
Not really sure why it would be impossible to transfer, not that I ever plan on getting rid of it. It's steel. The back plate already had to be welded back on. I remember seeing a conversion awhile back where people were swapping out the grip. So I'm not following you.

 

[Deerhurst]

Hahaha! 3D printed material melets too easily or isn't strong enough! Hahaha!!

I've been making industrial parts with consumer 3D printers for years! Fixtures, jigs and other things all the way up to electric motor mounts and flex couplings for motors. The right material, the right layer direction and the right settings makes stupid strong parts. I am printing some high temp materials up to 300c and even have PLA blends that are dried at 80c which is beyond when a standard PLA typically becomes soft and will stick to its self.

It's always a compromise. Doesn't matter if it is a metal, a thermoplastic or a thermoset plastic or any other material. You trade strengths and weaknesses for what you want in the final part.

I just do FDM. A whole world of stuff available for SLS and other types of IV cure and sintered printing, both metals and plastics.

 

[ecestu]

Hahaha! 3D printed material melets too easily or isn't strong enough! Hahaha!!

I've been making industrial parts with consumer 3D printers for years! Fixtures, jigs and other things all the way up to electric motor mounts and flex couplings for motors. The right material, the right layer direction and the right settings makes stupid strong parts. I am printing some high temp materials up to 300c and even have PLA blends that are dried at 80c which is beyond when a standard PLA typically becomes soft and will stick to its self.

It's always a compromise. Doesn't matter if it is a metal, a thermoplastic or a thermoset plastic or any other material. You trade strengths and weaknesses for what you want in the final part.

I just do FDM. A whole world of stuff available for SLS and other types of IV cure and sintered printing, both metals and plastics.

My man. So what are your thoughts on my insomnia-led imagination for a 3D printed body for a Glock mag M-11? :twoguns

 

[Deerhurst]

My man. So what are your thoughts on my insomnia-led imagination for a 3D printed body for a Glock mag M-11? :twoguns

I've been printing Glock frames and AR lowers, Glock mags, etc for hobby stuff. Designed and printed a pic adapter for VZ61. Most of these have just been eSun PLA+. All have held up well. I don't forsee any issues if you are just encapsulate the OE receiver and use it as a magwell/grip. You would get pin hole egging eventually with a plastic lower just like with the steel lower. The bright side is printing is so cheap. One of the reasons I'm starting to print Suomi mags. I can print 100 of them before I pay for one s-mag at current prices. Need more tests with those though.

I have a AWCY ACR stock printing now with 1913 adapter. After I get some dimms off it I have some ideas. Yes, that is foreshadowing.

Also ordered a SLA printer recently to work with resins and the various 405nm curable materials from the stuff you use for Warhammer models all the way to dental and engineering stuff.


Cutting up gun parts isn't my cup of tea. If you want to go further with your idea I would suggest making a dummy receiver, something like a pice of U channel with the receiver pin hole and a magwell hole, that you can prototype with before chopping the real thing. I would make the dummy as basic as possible and as far from being a functional firearm as possible. Then just model and print away!

 

[ecestu]

I've been printing Glock frames and AR lowers, Glock mags, etc for hobby stuff. Designed and printed a pic adapter for VZ61. Most of these have just been eSun PLA+. All have held up well. I don't forsee any issues if you are just encapsulate the OE receiver and use it as a magwell/grip. You would get pin hole egging eventually with a plastic lower just like with the steel lower. The bright side is printing is so cheap. One of the reasons I'm starting to print Suomi mags. I can print 100 of them before I pay for one s-mag at current prices. Need more tests with those though.

I have a AWCY ACR stock printing now with 1913 adapter. After I get some dimms off it I have some ideas. Yes, that is foreshadowing.

Also ordered a SLA printer recently to work with resins and the various 405nm curable materials from the stuff you use for Warhammer models all the way to dental and engineering stuff.


Cutting up gun parts isn't my cup of tea. If you want to go further with your idea I would suggest making a dummy receiver, something like a pice of U channel with the receiver pin hole and a magwell hole, that you can prototype with before chopping the real thing. I would make the dummy as basic as possible and as far from being a functional firearm as possible. Then just model and print away!

Excellent insight. Thanks for the tips!

 

[Tinman45]

Lol. I don't care about the market. If I developed anything, I would drop the files to the public.
Not really sure why it would be impossible to transfer, not that I ever plan on getting rid of it. It's steel. The back plate already had to be welded back on. I remember seeing a conversion awhile back where people were swapping out the grip. So I'm not following you.

Fair enough. If all you want is to use glock mags, though, you don’t necessarily have to slice up a registered lower. Maybe just print some kind of magwell adapter for one of the Lage uppers? That’s gotta be easier than what you’re describing, and doesn’t require permanent alteration? Plus you’d be able to angle it however you needed to for feeding without altering the grip angle. What is the advantage you’re seeking? I’m not trying to harsh your concept, I’m just not clear on the purpose. What mags are you using now?

 

[A&S Conversions]

My man. So what are your thoughts on my insomnia-led imagination for a 3D printed body for a Glock mag M-11? :twoguns

To me, this would be much more than a quick switch magwell problem. It is my understanding that the channel is the firearm. The magwell is an add on feature. So could it be legally done to a transferable receiver? I would certainly think so. The biggest issue that I can see is the structural integrity of the receiver where the magwell opening is. The welded in magwell gives the magwell area of the receiver strength. Removing the magwell also removes that structural strength in that area. To me a rail or other structure bridging of the magwell hole on the sides of the receiver needs to be added to the receiver to make up for the structural loss of removal of the magwell structure. I don't think guessing at it, when the market value of the receiver is pushing $10,000.00 would be unwise. I certainly think that there is a market for such a conversion, but the engineering and testing would not be cheap. I remember a member here posting some pictures of such a quick switch magwell adapter that was held on with a single screw. I don't remember any structure added to reinforce the structure of the receiver. I also don't remember any long term information as to how well it stood up. I have some interest in pursuing such a modular grip/magwell structure. But it is not something that we would pursue any time soon. Certainly with such a high market value of the registered receiver would certainly warrant actual engineering of the structure of the grip/magwell.

Scott
Manager A&S Conversions L.L.C.

 

[Tinman45]

Maybe dry run whatever you decide on with a semi-auto MAC? Put it through its paces for a while before slicing up a transferable?

 

[ecestu]

Fair enough. If all you want is to use glock mags, though, you don’t necessarily have to slice up a registered lower. Maybe just print some kind of magwell adapter for one of the Lage uppers? That’s gotta be easier than what you’re describing, and doesn’t require permanent alteration? Plus you’d be able to angle it however you needed to for feeding without altering the grip angle. What is the advantage you’re seeking? I’m not trying to harsh your concept, I’m just not clear on the purpose. What mags are you using now?

No purpose. Just spitballing. I use the old mags it came with, with no real issues. Would be interesting to have something different without spending an asston of cash.

 

[ecestu]

To me, this would be much more than a quick switch magwell problem. It is my understanding that the channel is the firearm. The magwell is an add on feature. So could it be legally done to a transferable receiver? I would certainly think so. The biggest issue that I can see is the structural integrity of the receiver where the magwell opening is. The welded in magwell gives the magwell area of the receiver strength. Removing the magwell also removes that structural strength in that area. To me a rail or other structure bridging of the magwell hole on the sides of the receiver needs to be added to the receiver to make up for the structural loss of removal of the magwell structure. I don't think guessing at it, when the market value of the receiver is pushing $10,000.00 would be unwise. I certainly think that there is a market for such a conversion, but the engineering and testing would not be cheap. I remember a member here posting some pictures of such a quick switch magwell adapter that was held on with a single screw. I don't remember any structure added to reinforce the structure of the receiver. I also don't remember any long term information as to how well it stood up. I have some interest in pursuing such a modular grip/magwell structure. But it is not something that we would pursue any time soon. Certainly with such a high market value of the registered receiver would certainly warrant actual engineering of the structure of the grip/magwell.

Scott
Manager A&S Conversions L.L.C.

Thanks for the well thought out post. I can see your concerns, but I feel like the magwell doesn't add to the structural integrity of the frame. I'm a lowly electrical engineer, so metallurgy or structures is certainly not my fortay. I do feel like the forces that are put on the frame are limited to the pin holes and the rear of the receiver.

 

[ecestu]

Maybe dry run whatever you decide on with a semi-auto MAC? Put it through its paces for a while before slicing up a transferable?

Interesting thought.

 

[strobro32]

I found welding the grip and trigger guard/feed ramp on the lower adds strength. I changed the grip on a m11a1 2x and noticed more flex to the frame without the grip. Also, even more material needs to be removed from the bottom of the lower for Glock mags because they need to angle further to the feed ramp.

edit:
I've been thinking recently to leave the complete trigger guard/feed ramp on the frame for structure but also to avoid needing to cut the trigger guard under the feed ramp and weld it to the lower, 3 points of connection. If the trigger guard was left in the frame, it would leave space behind the trigger guard fore the Glock mag release. It kinda works out better.

 

[A&S Conversions]

Thanks for the well thought out post. I can see your concerns, but I feel like the magwell doesn't add to the structural integrity of the frame. I'm a lowly electrical engineer, so metallurgy or structures is certainly not my fortay. I do feel like the forces that are put on the frame are limited to the pin holes and the rear of the receiver.

You are, of course, entitled to your opinion, but think about this, the bottom of the channel is what holds the two sides vertical. Without the bottom of the receiver channel, at the point of the magwell, the receiver is basically two vertical strips of sheetmetal. At 1,400 or 1,600 RPM with 350 ft/lbs of energy at the muzzle per round. That is a lot of energy going into the receiver. Why does the muzzle rise? Because the force is not held squarely behind the action. So there is rotation. There would tend to be compression at the top and tension at the bottom of the receiver. With a sheetmetal magwell welded to the magwell hole, the welded on magwell is holding the bottom of the receiver from pulling apart or buckling. Without the magwell structure welded in, the center of the receiver is basically two vertical strips of sheetmetal.

As far as structural training, I have an associate degree in C.E. & Architectural Design that I received in 1986 and never did anything with. So I have next to nothing to claim that I have structural education. But it would seem to me that the welded in magwell would add structure to the receiver. So removing the welded in magwell for a magwell that is quick change would tend to weaken the receiver in the magwell area. That is just my opinion. Such a project seems like a great one for an 07/02 manufacturer using a post sample machinegun receiver. It would be possible to use a semi for fitting purposes, but I don't think it would be possible to test the stress a machinegun receiver would experience using a semi auto receiver. A machinegun receiver experiences so much more stress because the is such an incredible release of energy. At $8,000.00 + market value, I don't think using a transferable for testing would be prudent. Certainly your gun, yourchoice. YMMV.

Scott