I've got an hour of down time and will answer as many questions as I can until then. Edit: still here and answering questions as of 2:10AM CST. Just got to Houston for the NRA convention and of course now I can't go to sleep

Comments: 299 • Responses: 26  • Date: 

CopernicuSagaNeilDT22 karma

I second the request for verification, but I also want to get a couple questions:

How long can a plastic receiver really last? How dumb is anyone who thinks this will get past airport security, since the barrel and ammo are still made of metal? How did you feel about realizing you founded the napster of guns?

redditmudder10 karma

In general, I plastic receiver will last several thousand rounds. It's the barrel that wesrs out. For the liberator, we did the best we could by making the barrel reaceable. It has a 40 degree locking cam and can be removed, replaced in a couple seconds

CopernicuSagaNeilDT10 karma

I am sorry, I was considering an interview I heard on NPR a while back and did not realize that the barrel was also plastic. That's fascinating...

Have you found that any particular round or style of firearm (Long guns v Hand guns) has a better performance with the materials a 3D printer uses?

redditmudder12 karma

Definitely barrel length is an issue. We've fired 10 rounds through barrels up to 8" in length. The general consensus is that shorter barrels are better, but they do need length for velocity. We'll likely use a 2.5" barrel on the released Liberator, which is an inch longer than the couple of photos Forbes put up. The key trick to barrels is to print the barrel on the z axis and then treat the barrel in acetone vapor bath to reduce friction. Untreated barrels safely fire 1 round only, usually because the last 1" or so gets torn off with the bullet. With acetone bath, the barrels fail predictably and safely above 10 rounds... A crack propagates down the barrel starting around round 10

CopernicuSagaNeilDT7 karma

Ten rounds... Liberator... Is the name a play off of he .45s the allies dropped over occupied France to the resistance in WWII?

Also, ten rounds is pretty impressive for 'plastic'. Do you have a specific goal number you're trying to reach or is it more of an 'as many as possible' thing?

redditmudder8 karma

Yes, our model is "DD Liberator" to commemorate the 1940's and 1960's guns of the same design.

For the liberator, I expect that it would be carried with many barrels to increase overall rate of fire. That is one reason our final barrel length is so short. I context, the liberator is to prove that yes, the technology exists TODAY. As you're aware, we previously released the ar15 lower in plastic and have now fired over 1000 rounds in that design without any failures. I believe these two guns encompass both extremes. Next up, we'll work on a longer lifetime gun that uses a metal barrel insert and possibly metal springs... Things you can buy at mccoys or home despot. And of course, the whole thing will be assembled without tools, except maybe a hammer to press hit the metal into plastic. Expect great things!

CopernicuSagaNeilDT7 karma

Cool... I've always had an admiration for the 'peasant gun'. The Mosin-Nagant, the AK-47, they all have a special place in history for being the affordable, reliable, effective tool. I do look forward to seeing what can be accomplished. Thank you for taking some time to answer questions about this and for facing the political fallout.

redditmudder8 karma

Thank you for your support. The entire gun movement needs as much support as you can offer. DD is my attempt to contribute to the national debate and keep our bill of rights intact

redditmudder8 karma

Yes. Our first surprise was that shotgun rounds are the absolute worst. We tried .410", thinking it was the easiest round, but the barrel literally exploded. We've tried several rounds and have achieved the best results with .380auto, a low power, low pressure, but highly lethal round. We're looking at using a necked pistol cartridge, but unfortunately necked=high pressure, which generally exodes our barrels.

CopernicuSagaNeilDT3 karma

.380? Wow. I would have thought that to be too potent, even with lower pressure, for something made of that kind of material. Any plans on experiments with 'plastic' projectiles?

redditmudder6 karma

We have an ammo permit, so it's defintely on our road map. Only so many hours in a day. I have an excellent rotary cylinder design that you dump powder and bullets into, but that'll likely need to be metal... I'll still prototype it in plastic ;).

Asti projectiles are on the road map, but I expect they'll disintegrate in the air.

redditmudder7 karma

Not napster, this is our own design, so I link it tothe open source movement.

CopernicuSagaNeilDT6 karma

On that note, what has been the biggest legal hurdle you/your business have bad to clear? I imagine the ability to make 'throw away' firearms without registration or serial numbers has been... sticky.

redditmudder16 karma

Our previous AR-15 design was done before we received our FFL, and since it was home made and a title one firearm, it did not require an SN. The gun we printed today is legally a title two firearm and is serialized. As far as throw away, we must now log the status/location of all guns we produce, so that hurdle is very low... We just tell the atf all the guns we've made on a particular day and that's it.

The hardest legal issue has been interpreting laws and opinions that are rife with contradiction, convolution, and cobwebs, since we're really pushing the limits of what out legislators have dreamed up. A month ago, steve israel was under the impression this was science fiction, so I expect we lit a fire today that we're now going to need passionate gun lovers to smother. We spent a large part of the past 3 weeks wading through the legalese, but now we're expecting smooth sailing from an operating standpoint. We are following the laws as they exist today, even though some don't like it.

redditmudder-3 karma

onus11117 karma


redditmudder-7 karma

ask me questions and that should verify. Sorry, I don't have any credentials other than a complete understanding of the gun You might have heard about today ;). Also, I'm sitting shotgun as a passenger in a car writing on my phone, so can't send anything to verify.

Edit: proof (?) http://imgur.com/KhKK84c.jpg

Wiggles4208 karma

If you can't provide verification please post to /r/casualiama. Thanks.

redditmudder-12 karma

http://imgur.com/wJSCCzl.jpg You wont find this picture anywhere because I took it...

Wrestlingisgood9 karma

Are you afraid that children may print these?

redditmudder14 karma

I'm more afraid of the "think of the children" clause. Children would need access to a 3D printer for hours and hours, and then obtain ammunication. In general, though, I think that it's a parent's responsibility to teach children how to safely handle guns. A Nation of Cowards is a excellent read that I resonate well with, so for more details see that text.

Wrestlingisgood10 karma

what about loonies getting a hold of untraceable firearms?

redditmudder26 karma

Does it matter if they have a serial number? Does the SN give you warm fuzzy feelings? If the police are looking up the SN, it's going to be after something horrible happened. Did that stop the crime? No. In most U.S. states, only the transfer between a firearms dealer and individual is ever logged. For ex, here in texas I can sell a rifle to a random stranger on the internet with nothing more than a handshake. Perfectly legal, and it happens thousands of times a day. See texasguntrader.com if this is news to you; it's the texas gun equivalent to craigslist

director2349 karma

what's the best printer to get? how much should one expect to spend?

redditmudder3 karma

Given what we know right now, the dimension uprint will work. We're working on loosening tolerances for the more commercial printers.

director2342 karma

cool, what would your guy cost to print realistically?

15Gs for the printer, what's the cost of the actual "cartridges"

btw, good for you guys, well done with all your work and thanks for answering the questions

redditmudder10 karma

Our cost is artificially high due to Stratasys' proprietary cartridges, which are $260 for material that costs $40 on the open market. Even at Stratasys' elevated price, the Liberator costs ~$45-55. Using other abs it wod cost under $10. We're working on a solution to stratasys' overpriced cartridges, but it's lower priority at the moment.

redditmudder4 karma

Our barrel is a solid abs p400 print. Barrel ID is 370 mils. Bullets disintegrate on metal target, despite the critics' thoughts that it isnt effective.

redditmudder4 karma

Our springs are abs. 2x .8" diameter coils, with a crossbar connecting them on either side of our plastic hammer. The frame accepts a hammer body, which has said springs press fit by hand onto it. The hammer body is installed on top of the trigger and mates flush with the face of the barrel.

umans14 karma

I was fascinated with your vice episode. Where do you see 3d printing in lets say 5-10 years from now?

redditmudder4 karma

In the next 5 years a lot of critical patents will expire, so people will be able to use some really key tech: heated build chambers will be very important for annealing, which is important for guns. For now, use your oven. But in general, I see the consumer models providing revenue for large and new companies to form to compete with the giants and bring truly innovative tech to the masses. And of course, we'll be there takjng advantage of the new tech every step of the way... Heck, maybe we'll even design our own.

ammonkapow3 karma

How long until the Liberator is done?

redditmudder4 karma

Current print time on revB is 3 hours remaining... Tomorrow we'll test it and then we'll either have it done or we'll make a few mjnor changes. The gun is done, except for some fine tuning to better center the firing pin on the primer. We had originally oversized the firing pin hole to allow a wider range of nails to be used, but that caused the nail to have a lot of wiggle room, resting in nonconcentric primer strikes. Primers have a very limited area that will cause them to go off, due to their anvil design. See wiki if this is unfamiliar.

ammonkapow2 karma

Any idea when we can expect a demo video like the ones we got for the lowers?

redditmudder5 karma

This weekend. We've already shot some video, but are focused on getting the design 100% before we focus on the video. We were 99% on our first print, so we just need to iron out a couple minor details. I'm holing that our second print is 100%, at which point we'll shoot a bunch of rounds and then put up a video. Given that this gun is single shot, it won't be as visually appealing as the 600 round AR video, but it sure will prove a point. Of course, we'll have people that'll say its a fake... We invite them to come stand downrange to clear up the disbelief. In fact, we're hoping willard foxton will live up to his promise to fly down to Texas andet us shoot him (http://blogs.telegraph.co.uk/technology/willardfoxton2/100008957/if-you-can-3d-print-a-gun-at-home-youre-welcome-to-shoot-me-with-it/)... Not that we really would (?), but I think he's earned a seat if he's interested in seeing it firdt hand. I would advise he not wesr a flak jacket, and instesd opt for a kevlar vest.

xzak1 karma

Please, summarize the concept of the whole '3d printed' thing. I remember reading about this and seeing a video of a '3d' gun and i was very confused as i still am.

redditmudder-1 karma

It's an expensive glue gun that now prints real guns. See wikipedia, sorry, I'm on mobile phone and cant link

DemonI810 karma

Not a question: Keep up the good work.

redditmudder-1 karma

Essentially working around the clock. Email us if you're good at what you do and can relate it to our project 60-80 hours a week.

Brouje-17 karma

So let me get this straight: you want to make it easier for people to kill other people? Go fuck yourself, you self righteous ass.

redditmudder10 karma

Hey, at least you didn't tell me to go kill myself.

I want to make it easier for people to defend themselves from the world's evils. It's impossible to think that a single person with a single shot pistol could take on an adversary with ANY other gun; we've literally built the most basic functional tool. There are no accessories, just a simple single mechanism for the huddled, unified masses to resist the tyranny this world will offer them.

Brouje-6 karma

It doesn't matter that it you've only created the most basic weapon. All it takes is a few years for people to improve upon it, and then improve upon it some more, and then by the time it's too late you realized that you've opened pandora's box and that suddenly you find yourself living in a world with an oppressing threat of violence. By helping give guns to anyone who wants them you're perpetuating and advancing the cycle of violence and hatred that we should be working against. To top it all off you think you're doing the world a favor, you sick fuck.

redditmudder2 karma

Glad to hear you have an argument this time around. Honestly, ideally I wish guns didn't exist, but they do and they're really easy to make. That makes them accessible to anyone. Pandoras box was opened a long time ago; we're just opening it a little wider to make sure enough guns fly out of it to give everyone a fighting chance. Of course, I'll reiterate that I'd choose nearly every other gun in the world before I bore arms with the liberator, simply because it is so basic. I'm happy to keep discussing, but maybe you can turn the troll dial down a bit. Discussion, understanding and reflection on others' thoughts is an excellent learning mechanism. And of course, if all else fails, we've always got guns to fall back on, or in your case, you've chosen a pissing match.

NewThoughtsForANewMe-27 karma

why did you sell your soul to help aid child killers?

redditmudder11 karma

We built a tool that has great value to society. How people use it is beyond our control. I can think of a lot of people who would have killed for (and with) this... One example: germany in 194x

AccusationsGW9 karma

germany in 194x

Which side?

redditmudder7 karma

If both sides had it, it would always help the underdog the most, as they have less access to technology. If I had to choose between the liberator and my M16, I'd take the M16. If I had to choose between the liberator and nothing, I'd take the liberator. Guns are the great equalizer, as long as the technology is available to all.