Print Receiver Countersign with airSlate SignNow

Print esign receiver

welcome back to awful tactical okay today i'm very excited to show you guys uh our latest 3d printed air 15 lower this is the third prototype and this is the first one to actually function without any failure so far i got 30 rounds through it right now and without further ado i'll go into some more details later i have all 30 rounds on video being fired uh so we'll watch all those right now and then we'll get back and talk about this all in a little more detail okay guys so i have uh the lower set of 3d printed air 15 lower assembled with a classic uh build kit and i've got just the standard 16 inch mid length gas tube upper on here we're going to give it a try but first i'm going to go show you all the functionality i will test it and show that it works so uh magazine it's locked in press the button there we go magazine comes right out so that works and now let's take a look at the uh we'll test the trigger and the trigger reset so i'll lock the slide back okay so slide lot back uh and now i'm going to drop the slide put the safety on pull the trigger won't fire i'll put the safety off so safety's right here and fired let's test the trigger reset so i'll hold the trigger down we'll rack it i'll let go and little click and i'll shoot fire okay that all works great um safety works so everything's fully functional i'll lock it back and uh we'll test fire it we'll shove our mag in there okay so let's uh let's do the test fire so 3d printed ar15 uh lower uh it's reinforced so we've got a rib right there about 100 yards right here give it a try okay and we're about to try so now i'm going to drop my slide okay we're hot okay it's two rounds and uh no signs of failure yet all right that's two more rounds and uh still uh still intact no cracking anywhere everything still seems to be working we'll test the safety again and see if that's failing safety works okay let's fire a few more rounds okay that was six rounds we've now exceeded the record the last one which is five rounds and uh i have a third of our magazine here so let's get up see if we get to ten rounds there we go 10 rounds and uh no signs of failure so it looks like our reinforcement has uh really helped uh see i'm not seeing any cracking anywhere uh let's see if i can uh i'll go prone as we can hit the little plate and see how it works there okay here we are same magazine and i'm going to try to hit that little plate got it [Applause] got it again missed got it okay we're doing pretty good here it was at like 15 rounds uh i'm gonna fire all 30 for the sake of testing and then we'll take a look at it inspect yeah i can okay until i'm not shooting with a real ar except that there is a view shoulder but there's a little flex still right here that you'll notice but other than that we're uh we're pretty good this uh yep we're uh we're open so fully functional 30 rounds and no failure so far okay as you can see i didn't have any problems at all uh the weapons accuracy wasn't really affected at all i was still hitting everything just fine uh like i do at the standard lower so it doesn't seem to be affecting that the only little the only downside i had was it still is a little bit flexible back here uh where the buffer tube is so there's still i don't think you can see that in the video but there's still a little flex it's actually kind of twisting sideways down this way because it's got the support on one side but not on this side because the charging panel is on the way and you can notice that when shooting uh it's slightly disconcerting if you pull on the gun real hard get a real tight cheek cheek weld but uh it hasn't broken at all and uh my i'm very high hopes about its functionality and it is fully functional um as you can see in the video uh everything works just like a standard mil-spec lower let's take a closer look at uh the lower and what i did to beef it up and get it to work okay so i did have to make some compromises uh when constructing the uh when designing a lower uh some of those were the two main ones uh was that right here uh if you can see i'll get it so you can see it easily on the screen uh right here i beefed this up significantly and it's a parabola rather than a curve right here by where your with your hand goes and it's very comfortable to hold with a standard classic build kit like the mil spec handle but if you try to put a magpul handle on here it will not fit because this curve does not fit the little tang that comes up on the handle that's one compromise the other one is the rear takedown pin you can see it's recessed in a hole right here and on this side it's also recessed so you can get to with your fingers you can push on it but you have to use like a cartridge or in this case i'll use a pair of pliers to push it through in order to take the weapon down you can't use just use your finger like you can on a mil-spec one so that's the other main compromise so if you give it a push so you can get to it and then the weapon comes apart and we'll just take the mag out now which you should have done earlier um and the front take down pin the forward takedown pin pops right out like it uh like a standard lower one does this one's a bit stiff there we go but you can get to your fingers and there is our lower without the upper and so you can see the main feature here that kind of sticks out is this big rib right here and what this does is it basically reinforces your uh your buffer tube threads so normally all that all that stress is right here right across this thin section here it's focused and concentrated and um let me zoom in for you so i can give you a more close look there we go uh force is focused right here and it breaks uh like you could see if you look at my two previous videos i'll put a link right up here so you can see them it breaks right at the rear take down pin and uh within us a few shots so the two previous ones that broke it two shots and it broke at five shots um this one here we've got 30 rounds with no signs of any failure so on so what we did to fix that problem is this curve you can see it this rib right here supports the buffer tube threads and so far it's done a really good job so the basic the idea behind this was i can put a rib on this side but i cannot beef this side up down here because i have the selector switch um it requires a very specific wall thickness between the inside and the outside so it has this this plane is very important of a very it's gonna be a very specific place so in order to be able to operate the selector switch and have it actually rotate so i couldn't beef this up at all in here and you're able to get your thumb in there so this side on on this side on the right side of the lower you can see it's been significantly beefed up and i can do that on this side because i don't have that selector switch problem and vice versa i cannot put this rib onto the right side because of the infamous bolt assist which we all love so much so we basically did what we could on both sides to stiffen it up uh this works a lot lot better than just beefing it up but we don't we could and so far it works so let's talk a bit about the post processing i had to do after it came off the printer okay so what i had to do as far as post-processing um was the only support material i used on this lower uh because i'm printing it once again i'm printing it on this surface here so it prints like this i've just in the design i've cut off the uh magazine well the front of the magazine was a 45 degree angle and that's the print surface and then i put support material underneath the uh on the trigger guard and what what that support metal did was basically keeps it from falling over during printing it doesn't hold any details up there actually aren't any uh there's no overhang on the entire unit um except in even in the holes actually except on the threads up here there's a little bit of overhang not even overhang it's bridging there's a little bridging on it there's no overhang on the entire receipt drawing that the printer has to cope with the entire the reason the purpose of the support material is just to keep it from falling over during printing propping off the bread or drooping just because uh it's so much 45 degree overhang so this overhang does not need support there's no overhang that requires support material support materials there just to hold up the 45 degree overhang so there is overhang it's just it's not uh critical overhang so it doesn't need support per se to hold it up in this case there's so much of it that needs to be supported and that helps more it gives more build area a bed area to stabilize the part while printing okay so that piece of overhang had to be popped off it was really easy to take off um it just takes a matter of seconds i had a couple little plastic blobs i clicked clipped off with a pair of side cutters and other than that the other post processing i had to do was i got a it's actually i got like a 25 drill bit set at lowe's so just your basic sizes like 15 64 is one of them but i took that set and with those drill bits i was able to clean out all the holes on this which i which i did the ones that i found really needed to be cleaned with a little and i drilled them out to i think it was seven sixty-fourths uh in the end what i drill them out to um i'm not quite sure about that but i think that's what it was i just picked the right the right drill bit size to match the little brass pin that keeps this uh captured and then i just put it put it in there clean out the flashing that worked really well um the only hole i didn't drill out with the takedown pin holes i mean i got to take down pin holes the uh action pin holes for the for the uh trigger and for the hammer i left those undrilled out and i left the flashing in them so it gives a tighter fit on the pin which worked very nicely i had to tap that in there and it seems very secure and then the hole for the screw that holds on your pistol grip i drilled that out to 15 64. so it's a quarter 28 thread on that screw and i just tapped into that 15 64th hole without any tap i just put it right in there very carefully by hand and it's a little slow you got to be careful to crack the plastic once it goes in you're good to go and it's a very secure fit basically like a nylock uh nut it's not backing out on you it's very it's very secure so other than that it took like an hour to put together all that clean up everything and i took it out fired 30 rounds no problems uh no errors we didn't have any misfeeds jams or anything on fire no problem so i was really really pleased with that there's one more thing i want to mention here guys and that is how the upper and the lower uh integrate together as far as with this with this brace input installed and you can see the brace let me bring it into the camera a little better there we go you can see the brace uh does not touch the upper receiver at all so there's no interference there i have it curved in such a way that it that it's actually got about an eighth inch of spacing off the aluminum of the upper receiver and then it's uh this part right here is straight so that when it's closing up it doesn't pop around or anything it just goes straight up and there's no contact or interference okay so i have the file for this available at hoffman tactical.com i'll put the link down here in the description to the blog post i put up on this i have some close-up photographs of it and i talk about the iterations with the other two prototypes i printed a little bit and i've got the files for this one i got the solidwork files and the even got the g-code file there for the prusa if you want to print it on a prusa it still needs some improvement but right now in its current configuration it is fully functional and it's structurally sound so i like to beef put some parts of it up for example the magazine well right here got a little flex to it and once there's a magazine in there it holds together nicely but that might crack if you hit the side of it so i got to watch out for that i want to beef that up a little bit and there's some other little details but as far as functionality goes it's it's pretty much watching watch 100 the failure mode i think is going to be rather than when it's firing breaking just carrying it around if you drop it or you hit it on something you'll break off there you'll break your stock off i think it's gonna be the failure mode uh but we'll find out and i'll update you guys on the status of this once i get a few more rounds through it and give it a little bit more wear and tear hey if you enjoyed today's video on this be sure to hit that like button down below that really helps get more views uh brings more people to the video i think this is an interesting subject so comment uh what you think about it uh if you have any experience 3d printing ar15 lowers uh be sure to let us know what you think and any improvements we can do and i'll see you again later