How To Pickup an Internal Thread for Repairs !!!

hey guys so find here in advance innovations welcome back to the shop you know I have been asked several times for his not several hundred times how do you pick up an internal thread when you have to reach a saree size recut repair whatever an internal thread well it's easy on an external thread because you can see it right on an internal thread maybe not so much because it's all blind the answer is actually easier than you think at least my solution for me is a good way to go so I have a part setup in the machine we're gonna take a walk out there load the camera and we're going to show you how I do it and if there's anybody out there that does it a different way by all means stick it in the comment line because I think there's a lot of people that would benefit by the variety of input you know just how the world goes around so let's take walk out the lathe I'll show you my setup and I hope you like it alright guys well for today's demonstration I am going to use a two and a half inch 12 pitch bushing that I've already cut in half so we can see what's going on blindly down inside this part now if any kind of luck that occurs today when this thing shuts down I'll be blocking the camera and that's really what I hope but I will give you the theoretical behind picking up the thread with it exposed so you can see what's going on just so there's no funny business my threading tool is laying across my ways right now and the tool holder that I will be using is a bxa - a Loris quick-change and in that I have a bushing adapter that I made it's got a one-inch diameter bore going through the center and I have sleeves that go in there with the one-inch oh d and the front is bored out to whichever size tool that I prefer to use for the operation this one is a 5/8 and that's the diameter of that bar that's laying right across right there what we're going to do is we're going to fire it up and we're going to coordinate the tool to the thread then we're going to blue up the threads and take a cut and see how everything works out so I'm going to pan back here for a second see if I can get a little bit wider shot what's going on there we go all right we'll try to narrate this over the noise of the machine so that you can hear what's going on let's get er done first step in my process is I'm going to put the machine in a comfortable position so that I know the extension of my boring bar or my threading tool is going to reach the bottom of the hole everything's going to clear I like the way it's set up gonna lock it in spindle it is all set for 12 TPI and I'm setting a hard stop against my carriage right now so that it can't go any farther this is my palm position the compound is parallel to the bed waves zero in line so if I turn my if I crank my compound it moves in and out now that's not the secret here because you can still break your tool off so let's take a look at what's gonna happen I'm going to slide the carriage away from the Chuck and engage my half nut once the Chuck is spinning just to assure that the carriage is moving in the direction I want it to move and if you've watched any of my threading videos you're going to know that I thread on the backside of the board and I thread out it's a great way to do it and I very rarely have any stress about crashing the tool so let's check it out [Applause] okay carriage does in fact move away from the Chuck which is good got the carriage up against the hard stop now going to engage the spindle as the carriage is moving with the half nut engaged I am going to turn the power off [Applause] perfect the camera is blocking or excuse me the part has come around and is blocking the view of the camera which is exactly what I wanted take my tool out of the holder I'm gonna load my boring part okay now the carriage is locked the compound is locked the only thing that moves is the tool I guess you can tell where I'm going now right gonna back this off I'm gonna move this inside my part now when you're doing this bear in mind that you can't trust your stop anymore okay that's really important to remember you cannot trust that stop you will have to re address where that is visually look down inside of your bore just so you can see it I'm gonna uncork the gearbox here and move that around see if I can get you a better visual on what's going on right here alright I think we have a much better angle on that right now at this time the rotation of the machine is timed with the carriage the half nut is still engaged I just inserted the tool in the holder and you can see that the tool is free to flute this will be about the only part in the operation where you're going to need to rely on the feel of the tool against your part what you're looking to do is get your tool down in one of these grooves right here until it starts bumping side-to-side I want to turn that just a little bit more there we go beautiful now as it bumps side-to-side you'll get a pretty good feel for how it how its sitting in there visually put it in the middle I feel you can put a pencil mark you can put masking tape on the shank of your tool and watch the stroke but for now let's just bump it back and forth I'm going to advance the cross slide you can see the tool getting deeper in the cut that way it bumps back and forth it gets smaller I'm going to advance it some more and there's a reason that I continue to advance it but we're not going to lock it down just yet alright I think the advance right now is about as far as I want to take it I can trust that I have what I'm looking for and there's a very specific reason that I'm doing this I'm going to put an indicator now on the opposite end of the bar now I'm going to bump my boring bar in this is my threading tool I'm moving it in you can see the minimal movement that's on there I'm moving it in it is now in contact with the far side of the thread I'm gonna bring my indicator around until I have a reading close to somewhere around zero there you go now when you return the threading tool to the inside of the pitch or whatever other side you'll see the movement on the indicator I've got about 13,000 tear which means six and a half on that indicator with that bar right dead center of that groove right I like it right there I'm gonna lock it down trusting my indicator to tell me that that bar is halfway between the movement that was present on that bar I am tightening up my tool right now let's lock everything down everything is tight and now we can trust or assume that threading tool is now positioned midway in the groove it may not look like it from the camera angle but I assure you that is strictly the camera angle this is where you look at the dial on the cross slide and see what your number is my number is 20 so write that down somewhere so in the midst of all of your messing around here you don't forget what number it was [Applause] at this point you can unlock your half nut take the tool out of the groove unloosen the hard stuff about to figure word I know somebody's going to get pissed off about that too bad guess what I just unloosen the hard stuff all right now you take your threading tool and you position it where you think you want to start I'm gonna bottom it out on this bore right on the bottom and I'm gonna move it 10,000 at my digital I know I am now 10th out the bottom of that group going to lock my carriage just for a second returning my hard stop back to position this is now my starting position for the thread we know that the tool is timed to the lead screw and I am going to blue up these threads and take a cut now the reason you don't want to blew them up initially is because the bluing can sometimes pull up in the root of the thread and influence that back-and-forth motion when you're trying to zero out your tool [Applause] if you have a mirror handy now it would be a good time to go and get it so you can see what's going on down inside this thread having a half a part like this is a real benefit for a demonstration like this but please be aware that you're not going to have the benefit of being able to look directly at the tool so just assume that this is blind the whole theory here the whole solution to this problem is to slide that back and forth to find the center of the groove and track the middle with the indicator that's the way I'm going to do it all right if all goes well that the tool is time to the thread the stop is set at a good location my starting number is 20 let's return to 20 once this thing starts to rotate and see what we get [Applause] my threading tool is currently sitting on the initial 20 that I used when I zero the tool itself to the center of the thread I'm going to engaged a half nut and as the thread pulls out or as the tool pulls out I'm going to dial in slowly until I start to see a chip this forsake this let's just move this down to it much slower rpm so that we can see 98 RPM I would never tread this slow but that's what it takes looks good [Applause] tindy my new number is 42 on my dial we do have some remnant bluing showing up on the tool let's keep going [Applause] all right we actually have material showing up on the tool which is a good thing if you have that mirror and let me get one little dental mirror like this works really well you feed it down inside of your part you can see what's going on if you don't have one get one you'll use it all the time and these are also very handy these are the adjustable kind they come in a variety of different sizes and some are telescopic as well this one is not this one is fixed it's about seven inches long that's about three quarters of an inch in diameter so pick one get down there and use it let's rotate this Chuck take a look partner I know that is an absolutely beautiful track down here in the bluing you can see that it has taken the blue off the entire thread yet still left a hint behind so sitting on 42 I say if I go another tooth now we're golden [Applause] this is the point in time that if you see an influence or a bias on one side of the thread or the other you would use the compound to make your move okay but I'm really pleased with what I'm seeing I'm seeing the blue come off I'm seeing a couple of high spots on the aluminum coming off and it is a very consistent cut if anything it is a little biased to that side of the thread but I don't think it's biased enough that I'm going to make an adjustment I'm just going to roll with it [Applause] another solid indicator as to exactly what's going on with your tool is to inspect the tool itself as it comes out if you have a clinging chip take a look at which side of the insert or which side of the tool that chip is clinging to that'll tell you the contact side and you can offset in the opposite direction this one is really even okay after the process you can see that the bluing has been removed from the rear of the threat and the front of the thread I would say that this is a win if you were just looking to take out a damaged spot for sure make sure that you don't locate your tool on that damaged spot because that would influence the center that the indicator told you what's sliding the time back and forth is definitely the way to go to pick up an internal thread that is a 12 pitch thread you know we have successfully removed the bluing from either side very pleased with that result I could guarantee that thread would still be inspect when you put the go gage in okay so we got thanks guys well that's the solution that I came up with you know if you can't move the carriage then move the tool but make sure everything that you have is nice and lined up and true and nothing's going to move when you tighten it down so keep an eye on the indicator just know your environment know your equipment the bushings and the block that I used I made and I've been using them for years so just make sure you keep everything straight and true when it comes to threading especially and you should be in good shape hope you got something out of that that you can use in your shop make your life a little bit easier thank you for watching as usual Joe Pyne exhibitions Austin Texas you

Channel: Joe Pieczynski

Views: 61,726

Rating: 4.9441586 out of 5

Keywords: Joe Pie, JoePieczynski, Advanced Innovations, advanced innovations llc, how to, machine shop, shop tricks, shop hacks, shop techniques, shop tutorials, threading, internal threading, single point threading, internal thread repair, locatating tools, positioning a threading tool, ID threads, ID thread repair, chasing threads, Diresta, Jimmy Diresta, Abom, abomb79

Id: H44zYTTDOvU

Length: 19min 51sec (1191 seconds)

Published: Sat Nov 02 2019