Anvil 034: Mauser 71/84 horked up barrel band repair

this screw is tight and yet even though this is tight why can I take this Barrel band off there's a common thing that gets destroyed this happens to be a Mauser 71 84. we're going to look at what it's going to take to fix this tell you why it broke and and how to not do a tear gun we've also got to make a screw through this small stuff day-to-day crap that happens in a shop let's get on a rabbit hole all right all right I got the white board up because I've got to show you the force diagram here it will not make sense when you watch me make these parts so we have a barrel band here and what we want is a clamping Force this way we want to clamp it right so one side of this thing is threaded this side over here is threaded so let's go ahead and draw some threads in here that is the hole if it's the threads right this side over here just has a hole in it so in order to do this we've got a screw here we're going to do the head on the screw slot right and it's threaded and then it has a stud sticking through it and that's what you usually see is the screw with the stud sticking through it what's missing is this blob over here and everybody gets this backwards because Watch What Happens here if you take the screw and I'm going to go ahead and redraw it in here if you push the screw into this hole here and it's threaded in here and I'm going to run the threads out and here's the head on the screw and then there's a stud sticking through like this okay and here is the swivel the tendency is to want to take this thing and screw it down tight and wonder why it doesn't work or Worse attempt to pull this out if you put the head on this and I'm going to have to redraw this I'm caving everything in here hang on so I'm going to start over again here and get you a clean drawing because hell is starting to confuse me if I have a threaded Fastener here threads threads and I have a blob on this end of the threaded device as I back this out this is going to push up against that this is going to push up against that and there's our clamping Force so what will happen is people either try to back this thing all the way out and they'll break this head off or they'll run it all the way in and they'll break that head off this is a captured setup this is designed so that it cannot come out in the field and get lost so same thing happened on the back end of that gun it had there's another swivel that goes back on the trigger guard that screw was also gone so it's a beautiful 71 84 Mauser and before seeing Arsenal takes it out to the range and shoots with it we're going to make a couple of Parts here we'll just jam through this and we'll get onto something else as with most things German this is needlessly over complicated with lots of little itty bitty vets uh all right so this screw comes out this is just to get the barrel band off the back see I dropped that thank God I'm not in a trench somewhere oh because without this little Eeny weeny screw we go nowhere all right this guy comes out I'm going to very gently pry on it always be conscious of the fact that you're hosing to finish up if you're not careful all right that's out now the entire magazine tube's got to come out of this thing so I've left the magazine tube on in order to get a little bit of purchase on the back of it you can see it's starting to move now once it starts moving now I can get back here now I can take the spring pressure off of it so that I don't unwind the Magazine spring up inside this stock and that that is what that is this is a beautiful piece of engineering but boy is it made out of little itty bitty things here okay so then that's on Unwound and two ounce ball peen hammer I'm not really hitting this very hard I'm just assisting it in coming forward Bruno's a little bit I don't know anal and a tad masochistic he was nice enough to take this gun apart from me and dynamite all the rust out of it or else we would be using significantly more Force than we are using right now okay that comes and in order to get the front Barrel band and hence the rear one over the front sight we must remove the entire magazine tube this is a good time to do maintenance boys and girls okay so I'm just going to set that off to one side here bring the front nose cap off set that down and then we finally have access to the barrel band so we can see here where let me see get it up against a decent background there we go when I take this screw out the head's missing off of it we'll pull in tight and we'll show you but the head's missing off of it so when it's in here it doesn't matter how tight I screw this thing down or up because they're always screwing things up right so let's run this in here and it's even been cross threaded ever so slightly no matter how tight I wind this down it doesn't draw the other side of this band back this way it doesn't draw it back this way so this even though this works this remains loose what it needs is a head on it so that as we're backing this up like I tried to draw as we back this up it would and I'm going to squeeze it with my fingers to show you what it would have been doing it draws This Together Tighter and Tighter and Tighter and now it'll pop right back open again so not only do we have to repair the screw but we have to repair it as part of this assembly we can't make the independent parts and have it all and have it all made on a bench and reassemble it on a weapon the idea behind all of this complexity was to make this a single piece that was more difficult to lose so why do they do this and then do all that crap on a foreign beats me a a public service announcement here not Public Service just just a self-effacing mark comment here guys I use a pair of dial calipers because they're accurate enough I'm not making a machine tooler I'm making a firearm it's a completely different environment right so I get it I own I own micrometers I own all that stuff and when I need them I break them out but when I'm just going is this bigger than that these are good enough in this particular case This Thread is a 255 by 27 it is not metric I looked at the 0.8.9 and one millimeter modulus and they don't fit the thread pitch gauge rocks back and forth in it the 27 fits perfectly so there is no way in hell I'm going to replicate the screw it's not going to happen so we're going to have to fix this screw and what I what I propose to do is draw The Temper off the top of this turn it down flush and then thread and insert and red Loctite another piece in and it should hold well enough to the uh to the work holding system in the Torches shall we I have the screw just just I don't have it down tight I have it just touched in here and the reason for that is is I don't want to Wick all the heat away but I want to draw any remaining temper off the top of this we still see that yes we can so we're good there we're going to go ahead and move this there we go that looks a lot better and all we're going to do is we're going to heat the top of this screw up and then we're going to let it cool off rather slowly we're not going to quench it we're going to heat this whole thing up it doesn't matter if this thing's as soft as a piece of chewing gum when I'm done but what I don't want to try to do I see here that someone has attempted someone has attempted to drill a hole in the very very top of this thing someone has thought about doing this repair before and just didn't quite have it oh more heat more heat on screw oh I'm gonna take that sucker up till it's dull red there we go you see it's starting to Glow there I'm going to start throttling the heat back hold it in that stain for a little while it's all red maybe an orange so I'm throttling the heat back nice and slow because I want to start cooling this off very very slowly now because it's not in the Vise very tight we're not losing a lot of heat to the vice Jaws I'm going to let that sit there and cool off all by itself I've switched vices and I'm in my soft Vice jaws and now what I'm doing and yes I know the drill isn't vertical what I'm doing is I'm walking this hole into the center foreign there we go this is just a sixteenth of an inch drill bit and I have the luxury of getting that hole right in the center where I want it I'll pile it down with the 16th still haven't decided what we're going to tap it to yet yeah we're gonna go a lot deeper than that this is a blind hole and because it's a blind hole we have to be careful that we leave enough room for the starting part of the threads in order to get down in it here we go so here comes an obvious question why aren't we doing this in a lathe well how the hell are you going to hang on to it if I was making this screw I would have left the head part about that long so I could grab it done all the Machining cut it off turn it around I don't have that luxury here so we're going to have to kind of do it the hard way because I am gunsmith Brute Force did not work obviously I did not use enough Brute Force must use more [Music] and why I do not have a really really good handle on this girl here there we go and yeah I intend to drill this hole damn near down to where those threads are I'm going in deep you can't drill a hole through that it'll make it weaker really I'm turning it into a column it makes it stronger oh boy let the structural guys go after that one now where light gets too short because if you snap this drill bit off in this thing that's where life gets short expletive deleted okay I'm gonna walk over to my grinder here real quick and kiss this leave it running I'll be right back all I'm doing now is squaring off the end of this hole here well I've got a moment all right all right and we're back okay let's see here um all right so now what I've got to decide is is what size screw do I want to put in that and then we'll red Loctite red Loctite is some amazing stuff it uh when you put it on don't plan on taking it back apart again the blue stuff lets you take it apart in our particular case I would like this to become a single structural component so I'm going to hunt around here and find the kind of screw I want I'm going to mic this and I'm going to say all right I don't want to compromise the structural Integrity of the wall so there's a limit to how big I can go but the larger the screw the easier it is to tap we'll be back okay so I've got a screw stuck in here see that screw popping up and down what I'm going to do now is take this 648 screw and make the head diameter a little bit bigger so what we're going to do we are going to heat this whole block up in the top of the Vise and everything this is going to be a disaster let me set this light off I'll show you what I'm doing I get the head of this screw good and hot you'll see when I pull off there see how it's orange that's what we're doing but I gotta have the lights on so I can see so I'm walking a hammer around this way so I'm Dome heading this screw and I'm just flattening it out so it's larger in diameter and I get the small threads I want with the big the big head so there we go you can see that that the head of that screw is now three times the diameter it was put in the lathe and cleaned it up and then we'll tap the other hole so while we wait for this thing to uh to cool off we'll prepare the hole let me shut this torch down here before somebody hurts themselves and that would be me all right 648 tap and you're going to do a quick pan and you're going to look at this and you're going to come right back to me right there by my finger see it 648 the diameter to Taps 138 thou you got it the drill diameter is a number 31 which is 120 000 there is no fractional equivalent if we wanted the clearance drill it we have these numbers over here this thing hangs right in front of me I don't memorize these numbers I just look them up so we're going to have to drill the top of this screw out to that number number 31 drill which I have which I have procured and then we're just going to Chuck this thing in the drill motor which I think I left uh with drill monitor yeah here it is right here whoa damn all right so we'll Chuck that in the drill motor we're going to open up the hole to the right size a little bit of lubricant in there now we're going to do an idiot check and make sure that this thing is the size of the tap which I set down right here does that feel right yeah it kind of does but I'm telling you what this drill feels a little bit big so I'm going to make sure that this is 120 000 drill bit and it is 120 000 drill bit so what the hell happened here oh here's what happened okay this drill bit was hand sharpened by me after it was destroyed while we were making parts for the Pederson device and I'm going to tell you the Pederson device cool AF but I have never been happier to see a gun go back in the box and go back to its to its owner so what this drill bit is doing is it's walking in a hole this way it's not going straight down it's coming in this way and it was wallowing it out and I saw that because that hole just wasn't getting it so let me see if I've got another 120 000 stroll diameter that's a 105. this looks like a 120 right here uh there it is I have an entire tub full of in this particular case tap and die number six let me see if you can see that there it is this is tap and die number six and it's got all the the dies the Taps and sharp drill bits in it this number 31 drill bit we are going to store over there if you hear that hit the floor yes that's that it's no longer in the gene pool all right uh that's a 125 I got a little smaller and we'll go ahead and we'll get this whole board out and we'll keep moving so stand by here uh drill bits there we go why can I not find 120 thousandths drill bit oh there's one right there very good very good we're golden right here that's us um good Lord Mark wake up there we go now I'm on I'm sorry about that delay I don't care what it says on the drill bit I'm actually watching I'm I'm looking at what the what the mic is telling me there we go that's better [Music] now as you're opening this up it'll be obvious the hole just stop moving there goes and stop right there that's a deep ass hole too look at how deep that is that's that deep that's deep enough right all right 648 temp we got a little bit of oil guys I don't plug products on this show but when I talk about Aqua glass it's because it works and it's functional and it gets it done for me this little tuba Lucas oh my God like I said I'm not doing product placement but I'm telling you as a tapping lubricant and working up inside of a gun you cannot beat that stuff it is absolutely whale snot um anyway I said I'm not plugging anybody's stuff the only thing I'm talking about is stuff that works and it's not Shameless okay so we come back and we we break the chip come in break the chip you gotta be very very careful how much torque you put on this thing because if we snap this bit off we are done done like done with the capital D okay here we go you'll feel the torque wind up hard when it hits the bottom of the hole it will just go and you'll feel it if it squeaks you're done all right here we go I'm pushing with both fingers and counter torquing this I'm trying to be really really polite here we get near the end and that's the end right there excuse me okay here we go I'm just taking my two fingers and lifting up like this just so that Oneness comes out it doesn't twist out all right then load this down ah I moved the camera sorry why is this air hose kicking my ass here we go better we got it there we go all I'm doing is blowing up blow this out had a little bit of a camera move there sorry about that I caught the air hose on it Bruno was Johnny on a spot [Music] [Music] all right paper here a little bit of 400 Grit I want to make this look too good because it's going on 130 year old weapon for God's sakes so in the aluminum Vise Jaws here I've got the piece that we made trapped in the aluminum Vise Jaw so I don't crush this thing and what I'm doing now is just test fitting and making sure that before we try to put it all together again we got it all in one place and we do because there's no way to put any torque on this thing without having it in the vice Jaws so here we go there's the barrel band okay so this will go through that goes in there all right let me make sure that's going to squeeze and then this goes in here let me get this right of course like with most things that we video the time to find out that something is screwed up is before you turn the camera on but this is a day in the life here we go all right wow boy somebody else had gone after this thing I'm going to tell you what I'm hanging on to it there and I'm trying to get all this here to thread up and it's not going through so let's take this apart and find out why we're just having all this malaise here what happened ah it's out of round okay what a pain in the neck yeah threads are getting screwed up all kinds of craps going on here well then what in the name of Sam Hill am I gonna do about that well I've got a very very aggressive wheel over here so hang on a minute you're going to watch me or listen to me do this it's almost like um a piece of metal got in the way it started hosing up these threads and we don't want to do that just hosed up threads are the last thing we need to kiss that there and we're going to come right back all right here we go so I have to get these threads to run and what I'm looking at from my line of sight is I'm making sure that this screw is going in perpendicular in two axes okay it's got to go in perpendicular in X and Y so that I don't strip this whole lot it was starting to strip it here we go so now I can run that in ah there you go you see now it's going all the way home so I should have done this before I attempted to mount the bayonet put these things back together again in stages I guess would be the only way to say this okay so we'll pull this out all right now we'll put the band in we'll make sure it's free to move and it is put that in and then I'm going to get a clamp here foreign Ty sucks all right what I'm gonna do with this clamp is I'm going to squeeze all this Gap out of it here if I can I'm going to try to squeeze this through so that the uh the end of that sticks out posed up that's got to stick through there we go what I want is the hollow end of this screw to stick out here so that I have a place to attack it with that stem and if it's not free to move you'll never be able to put it together because I'm a hot sticky mess today I just knock my little clip clamp off there so let's see if we can get up in here and cause that to be squeezed uh I don't know here hmm um okay I'm seeing what's going on here the band the swivel is taking up all the rooms so the threads are actually pushing up against it so the only way we're going to be able to get at this is to unthread it and if we unthread it the other side will collapse and allow me to do what I was trying to do which is make this stick out wow now when this was made originally they would have heated this thing up with a torch and just made a little button rivet like we made when we did the 1919 there we go see how that's in there like that there we go now it's squeezing so what I want to do is squeeze this together in such a way that we can work on it so we'll leave that up like that okay here we go I'll do it up here you see how that's coming together like that we'll bring that together and then we're going to take our little piece that we made Put a Little Squirts of um red Loctite on it and be done with it so little Spritz it was a red lactate yeah I have almost no no room to work on this here this thing is gonna kick my ass all the way out the door but if we do this right you won't know that we made a repair you won't know that we did it and the true Pro can get in and get out you never knew he was there okay hang on here okay oh what a pain in a butt there we go now it's going in there are these days when my fingers don't work and I'm telling you what you are getting to preside over a very very low dexterity day okay we're almost here I have these days when gravity sucks and this is one of them we're almost there now I'm going to pull this out and I got to hold it in my hands so that I can get the last little bit of torque on it there we go okay so now we have a button head back there the screw head back there and in order to tighten the band down we counter intuitively loosen it in order to tighten this band you would back this out and as you back it out it squeezes together so you see it's totally squeezed together here but as you push in this way this Gap gets larger and larger and larger it's contraintuitive and that's why these things get screwed up in the first place there's a stud here and there's a stud on the other side that is designed that when you pull this Barrel bin down it's got something to push against that's not screwed up and it needs to stick out so we slide that over and we walk this screw out until we draw a torque and we're almost there we've drawn torque and now the barrel band doesn't move and we're in the game it's maintenance not everything you do inside this shop is all that sexy it's stumping as simple as just throwing a hole Down The Long axis of a screw and as always it's been a pleasure guys um foreign [Music]

Channel: Mark Novak

Views: 40,757

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Id: IfU6gF6Ppf4

Length: 31min 50sec (1910 seconds)

Published: Wed Jul 14 2021