Chasing and Repairing Damaged Threads

hey guys don't fight here to advance innovations welcome back to the shop today's presentation is going to be about a process called chasing threads and funny story the reason that chasing threads us is near and dear to my heart was when I was a young man I was working in a shop it was a molding shop so we had a bunch of injector nozzles and you know they're all pipe threads right big pipe threads well God brings a injector nozzle into the shop and he had dropped it while he was trying to put it back on the barrel dinged up the threads naturally you're gonna chase those threads to repair them so he gives it to the guy was working with us said would you mind chasing these threads for me now this practical joker Lenny was his name he laid it down on the floor and he kicked it and he chased it okay he ran and that's a true story I swear to god he kicked it and he chased it and because of the pitch of the thread this injector nozzle went out around the workmen she came right back to where I was standing watching him do this it made a complete lap and came right back and he picked it up and he hands it back to the guy he says okay now that is it God's honest truth he couldn't have planned that any better if he if he sat down and can now anyway chasing threads before I really get into it show you how I do it a lot of people do it there's just one additional detail that I want to share with you that I haven't seen anybody really explain and the best way to do that is with word association if I can clamp a picture in your head then you may just say okay I get it okay the best way to do that is with a train I've been thinking about how to explain this so that you understand what's going on so imagine a train there's my train right there behind me you have an engine in the front or in the back it really doesn't matter so but for this particular discussion engine is in the back think about an engine later the engine lathe is driven from the left hand side the belt comes up from the motor to some type of a pulley custard gear cluster goes through a billion of gears and shafts and key ways the spindle starts good turn okay if your lathe runs directly off of your motor well chances are you've got a very special machine because I've never seen one like that but they may exist okay the train this train pulled in the night before stopped the guy puts the brakes on let's just assume there's no brakes on all these cars because they're old and busted now engine stops what happens to the train because all of these couplings reach the extent of their design characteristic so the train gets longer okay check this longer in the morning he comes out so it's okay time to go hook the training gear and that's when you hear the train yard you hear the boom boom all the couplings are hammering together as the train starts to pull away well this is the same thing that happens inside of a ninja late when you fire it up or only happens really quick you have all of these gears that are meshing because they're not exactly spot on where they would generate so much heat the Machine wouldn't melt and you have key ways you have a bunch of different things that all have to be loaded up in a positive drive direction before the machine turns on at speed now if you shut it down there's a moment where all of these little couplings relax and god only knows what's going on inside that machine because you've just shut it off and you shut it off from the drive end you didn't shut it off from the nose if you stopped it at the nobody chances already would be better but stopping it at the motor motor stops first but shuts it down whatever things loosen up when you chase a thread or even when you run a metric thread on an imperial machine and you don't get to disengage the half nut this could really come in to play and when you chase the thread nine times out of ten it does come into the plate so what's the process of chasing a thread get the Machine all set up get your part squared away running true you got all your pitches pile in now I am assuming with the topic of this video that you know how to run a thread okay so I'm not going to get into the basics of tool positioning and fish gauges and compound setups and all the things that are going to generate comments don't even bother please if you're not quite sure how to run the threads there's a lot of other quality videos online something even on my channel that may help you to get there and understand more about picking up an existing thread or the skills required to have confidence to attempt that that's what this is all about okay you got your machine it's running everything is good parts in there it's all true you engage the half nut with the half nut engaged with the carriage moving with everything dancing and singing we'll shut it down do not disengage the half knot well did you just do you just stop the train so there's some Coast machines going to coast the carriage is going to Coast a little bit things are not going to be in the exact position that they will be when you are running that thread things have changed because of the deceleration the drift the Coast whatever you want to call it things have changed so this is part one of chasing the thread the machine is stopped it's in gear everything is cool this is only going to get you close this is when you use your compound your grunt lights your headsets magnifiers whatever and you put that tool you physically change the location of that tool with the half not engage with the compound whatever you need to do get that tool lined up in the slot of the thread now in doing this the starting position of your threading tool has changed so if you're running up against the stop please realize that you may want to reevaluate where that stop is set the timing of the gears the timing of the carriage Tyrael thread should not change so you can disengage to have Knut move it back to a nice new starting position and when you engage it it should track relatively close to where you want it to an operative word relatively close doesn't mean it's going to because of all of this done' well that drift so once you've got it lined up on the first operation once you think you say okay I'm close take your cross line and back it out because if you engage it I guarantee you're gonna see things happen that you weren't playing enough and you're not gonna like so I'm going to run a big heavy thread it's going to be a left hand thread it's going to be a very coarse pitch and that is strictly so that I can get a camera down there and show you exactly what I'm talking about I'm going to take the part out I'm going to put the part back in that's a nightmare taking the threat out of the machine before it's done it won't do it now second topic before we go out can you indicate a thread not so much no because the indicator is going to bounce off the high spots and jump all around and really you know I've never seen a good way to do it if anybody out there has a good way other than what I'm gonna suggest by all means post it in the comment line I'd love to hear how you guys did it if you have concentric diameters known concentric diameters to the thread that you need to repair well then get them running true and just pray that the guy that made the part before you didn't use that nut as a gauge and did it the right way you make sure everything was true or turned at the same time and you can trust it and do the Chasen procedure the only way that I could tell you how to indicate a thread is to make the OD of the thread if it's in good shape make yourself a sleeve slide it over the thread indicate the sleeve I don't see any other way to do it I personally don't see any other way to do it if you want to check a thread if the thread is running concentric - yo D a lot of people are worried about this but I can tell you you can have a perfect pitch diameter on a thread that is not cut concentric to the ouvea the part that you're working on and when it goes you try to assemble it doesn't work why because stack tolerances stack dimensions being what they are you are outside of the range of a good fit somewhere and it's going to lock up even it's got perfect pitch diameter it's still not gonna work how do you check that use one wire use two wires but only use it on one side of the part put the wires in the root of the thread OD thread might get come up with your number turn it apart 90 degrees like it again if the thread is not cut concentric to the OD of the part you're going to see differences in these readings this is going to show you that eccentricity or whip that you really can't see with your eye but you must put the wires on one side of the park so you're using the root feature of the thread has one locator and the OD of the material has the other locator and if there is a discrepancy and concentricity you're gonna see it that's the only way you're gonna see it all right let's take a walk out the machine take a look at the thread that I got hopefully I can get this camera in there and film it without crushing either the camera or the machine and I'll show you exactly how I would do you know chasing a damaged thread and initially let's take a walk in a heavy damage scenario like this you can see what I just did to this thread almost a sin to do that you can see the Bulge into the thread profile as it comes around the bottom you can see the Halfmoon bulge that has formed from the punch in three locations now although I will not be able to restore the crest profile right there what I'm looking to do is put this back in there pick it up sufficiently so that I can put the tool back in that groove and clean off that ugly spot okay that's the challenge I think if we're gonna review options on how to repair a damaged thread let's review all the options naturally if you don't have a die that you can pass down over top of the thread oh they sell these things these are called thread files and you can see on the reflection there this is a 28 on this end 32 you'll have eight different pitches for a file so naturally if you have a bunch of different threads you want to repair you have to buy different size thread files I've never particularly cared for these these are kind of in a emergency only type use in my shop but it's nice to have them on hand if there's something that you just can't take the time to set up a single point or whatever they also come in metric now I keep this one in the plastic because if I touch anything metric I break out in a rash only kid good thing you know about okay thread files keep them in mind next thing and certainly one of the easiest solutions it's a three sided file by default three sides is a 180 degree triangle 60 degrees per side most Imperial threads and a lot of metric threads are sixty degrees if you're damage of your part is on one side of the pitch and not the other it is a really good idea to take one side of your file and buff the teeth off of it okay the smooth side of the file goes down into V against the clean part of the thread that way as you're repairing you're only removing the damage on the damaged side the pitch and not on the other side so clean one side off if the whole thing is smashed in then by all means use a triangular file and do both sides of one time naturally available in a variety of different sizes cleaning the burrs off the top of the thread believe it or not a round file as it sits across the pitch on the top it hits the first side of the V really nicely so just don't put too much pressure on it or you're gonna end up with an undersized OD three different ways to do it or if you have the dyes available if you don't there you go all right number five when you have damage to a part it is very possible that you're going to have distortion in the thread that is movable depending on how soft your your material is if you have a park that's smooshed over in one direction get put a punch down in there and try to dislocate or four relocate some of the material as you see fit be gentle but if it moves too easily it's probably fractured and should come off that way you don't have this little remnant artifact jumping around in your assembly that's gonna act as a little miniature lock washer at the worst possible moment but let's put this guy back in the machine and pick it up and I'll show you how it's done sorry how I'd do it anyway if you are like the majority of the machines that I've seen your compound is probably set up like this for your threading operation well when you're gonna chase a thread I would suggest strongly set it up this way in line with the travel of the machine perpendicular to your part that way when you Center your threading tool in the groove when you have to pick it up and you can't move the entire carriage and you only can move the compound well any left right movement of your tool will not affect your depth I'm sure you can visualize it if you were set back on your twenty nine and a half degrees or twenty eight or whatever you set it at because I've thread with my cross slide not with my compound any movement left or right of the tool is going to result in a dive or a withdraw so if you want to just a couple less things to worry about on your first attempt to doing this move this around a zero square this back up to your part and set it up this way you're gonna be glad you did it's just one less thing to worry about unfortunately the demonstration that I'm about to give you was shot before this segment so my compound is set this way thirty degrees yeah I know it's 30 degrees off the wrong axis but trust me it was thirty degrees for the job I was doing so when I moved my tool left or right in the setup you're about to see I do have to correct the cross slide in order to maintain the same depth do it straight cz er next step in the process is to time the carriage movement with a thread don't worry about where the tool is realistic Lee you don't even need the tool but I'm leaving the tool in so I can have a visual I want to stop my tool somewhere well into at least the halfway point of this thread because of all that slop that I showed you on the port so I'm gonna start the Machine up wait for the numbers to come around I'm going to engage the half nut and then I'm gonna shut everything off power wise do not disengaged to happening [Music] [Applause] [Music] remember this is strictly to time the carriage movement to the thread nothing else you're not worried about the cool this is all happening too fast for you then slow the RPM of the machine down and it will give you more time to react between your controls [Applause] this is where you use the compound to align the thread tool to the profile of the existing thread right here they're the first step in successfully re indicating apart to make sure it's true I'm just gonna slug it up for now in the chunk it's not tight first thing I'm going to do is indicate that small land right there now I cheated and I have a square face that I know was turned at the same time as the diameter this gives me an advantage of knowing that the part is not sitting in here true in one spot and whipping if the front of the part is true then although it may be eccentric it is axial eccentric so I'm going to indicate the face first and I'm going to tap that until it runs true I'm even taking the threading tool out just to really add some fun here the indicator holder is a US general model 387 it is about 45 years old so if you can find one good luck sears also made one for a while and it was pretty identical so if you can find it get it it's a great little tool I don't think you've heard me say before if the indicator needle is not moving and this one is not moving [Applause] reflects the indicator armed in and out just to make sure that you are not bottomed out on the indicator and in fact we have a good reading so let's go for concentricity now next step once you successfully indicated it to zero make sure all of your adjustment screws are nice and tight we're not tight but you don't want them loose if it changes anything do it again just to double-check myself I'm moving to the nose journal I'm going to check that one as well now that's within a couple of tenths I'm going to leave it alone [Applause] back into gear I'm going to do this at 320 rpm I'm kind of liking that camera angle it works for me I can watch little TV here if they works well okay I'm gonna move the starting point of my tool back to somewhere around the original group I'm gonna set a stop and I am going to remember that this stop this area where this is bumping up against it's gonna have to be adjusted it's not going to be the same this tool is going to migrate this way to change everything I'm gonna back the carriage off of the park to make sure that the direction of travel is what I'm looking for I am also part now with my tool you can see the tip of the tool I'm not touching the part I'm going to engage the half nut let it run about half way into this thread so all the slop is taken out of everything and I'm going to shut the Machine down all right perfect which is where a lot of people will light up the top of the part with everything they've got trying to see as much as they can but you're gonna shoot yourself in the foot got yourself a piece of paper towel leftover pad whatever you got put it under the part give yourself a nice reflective background to the profile that you want and then get the light off the top of the part and light up underneath the part instead right and that's like having the I'm character love it we've got a little bit of reflection on the tread but it gives you a nice edge now with a combination of your compound and your cross line get the tip of that tool down in that groove as close as you can and if I could look through the camera I think you can see if you're looking at what I'm looking at you can see unfortunately the camera is really blocking my view here my view shows me that the right side of this tool is closer than the left and I have contact on the left back down a couple we have a little oil influence on the top of the tool check it again okay just for yucks I am going to snug the compound in court my number on my cross line is 46 so when I start my thread I can start my thread but not on 46 stay at least 10,000 depending on the extent of the damage you don't want the thread coming around and banging on the tool so use your judgment as far as how much you want to impact that tool on the first try I'll start off at 20 you go from there a flood is at least so terrible I'm gonna blew up the threads now and it put the tool back to the groove you can mess around with the carriage and the cross line at this point as much as you want that it's not going to change the timing of the carriage when you engage the happen back out off the part anyway just so I don't eat my words remember 46 with my number so I'm going to go to 20 right now and I would say we're going to see three distinct chips come up in this part and if you do not want to mess up the timing of your thread do not take the machine out of gear [Applause] okay we have contact on all three as we do see the white showing through from the blue we are tracking good let's go 4:30 on the [Music] 4:40 on the devil actually 35 I'm not going to get a little excitable here this is where you need to be patient you know the whole train analogy that I showed you on the board this is where you have to be patient and realize that things are not as they seem when you initially locate your cool thirty-five [Applause] you can see quite clearly that the ready pool is definitely engaging the damage that's a good thing and all's I did the move the chucked was to disengage my electronic brake timing it's good good [Music] [Applause] we are right there surprise contact in the rear house [Applause] this is a very superficial cut the blue on the inside of the thread we're gonna call that side of the trend the inside blue is starting to be removed but not on the outside I'm bringing the back to compound off running at the exact same number [Music] I am expecting no chip at all 443 creeping up on the 46 we saw a contractor forty-four see something that blue coming off something over 45 pretty close to finish size starting to show traces on either side I'm going to go to 47 and then check the profile double cut at 47 you can see that the blue is remaining on the impact side it's clear on either side which means there's no distortion on the impact side the back side we are still having a little bit of blue on either side I am going to back a compound out now I'm not doing the cross light I'm going to back the compound now it doesn't matter what angle the compounds are we're just looking for anything that's going to give us motion along the axis of the party back it off in others now all I want to do I want to start seeing the blue on either side of that white cut right there the Virgin aluminum I want to see the blue on Beaver side start to go away that way I know the tool is tracking where I wanted to track that's the damage that's what I'm going to address this is a 5:46 before you sit this is the patience part guys there's no quicker way to do this if this is a critical tread you don't want to rush you leave it where it is I'm just gonna go deeper got 450 so I'm scratching but nothing positive expect to compound off another's now this way still see the blue on either side of the damage but we're moving the cutting tool this way to address 1000 at I'm [Music] [Applause] sir not yet okay we'll hang on with the narrative and we will just make it happen we're going to move another town make it to this time you you [Applause] okay that is a successful repair guy and use my handy-dandy Randy Richard in the shops forever here too pointed out we no longer have any blue on the other side of the damage the existing blue that you do see is the impact so that is below the profile of the tool you are not going to get that out and she as it comes around the bottom in this area right here the B is really clean where the damages beside still some remnant blue left so the major or the pitch diameter of the part has not drastically changed benefit you're going to make contact nothing is ever going to go back in exactly the way it came out we're gonna get some alcohols if I can remover clean this thread up and we'll get back in a second [Applause] anytime you have damage to a thread make sure that you don't have a fractured element that is hanging onto the part that it's going to jump off down inside of your mating piece and act as a little locking wedge inspect it very closely for anything that may be hanging on we're trying to break off let's see if we get a nice close look at that profile you look up here against the black contrast on the top you can see that the swelling damage from the impact is gone you are not going to be able to take care of the top so if the boss comes running out and said that you didn't fix it tell them well you don't put it back together and then come and see me yeah that's how it's done guys I wish I could have 12 cameras running at the same time so you could see exactly all the combined compound and cross-slide moves but try to bear in mind the movements with the compound are going to affect the depth of the thread so make sure every time you make a movement with the compound you've backed the cross slide out and start a couple foul away from where you were that is all I got for you and I hope that's still in focus it's really hard to tell it's all shiny I would say that was a successful repair keep in mind that you can like I said put a sleeve over top of the part to indicate the thread if you need to and be patient that's how it's done thanks for watching alright guys well the first time that you chased a thread you're going to be very proud of yourself when you come up with that positive result but the key to a successful chase job on repairing a thread it's a setup naturally make sure the part is running true concentric everything is solid all the machine as dialed in you're you know exactly what pitch you're supposed to be set at so the set up is number one patience is number two don't rush it when you get close make sure you blow up your part watch it dust it make the adjustments be patient if you're a patient you will be rewarded for your efforts anyway I hope you liked what you saw it's fun to do practice make a part bang it up put it back in to fix it before the real deal comes along and you have to sweat because a customer sitting in a lobby with a cup of coffee going oh hey I gotta go anyway thanks for coming back appreciate it hey we get a lot of emails messages from all over the world and I am really digging it South Africa's checking in Australia is always checking in UK check it in I'm getting just great feedback so do me a favor when you leave your comment just leave me what country you're from because I really enjoy seeing that this channel reaches 127 countries around the world every month and I am just flattered by that so thank you very much go by in submissions Austin Texas you

Channel: Joe Pieczynski

Views: 60,370

Rating: 4.8953791 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, chasing threads, single point threading, thread repair, diresta, jimmy diresta, abom, abom 79, mr pete, picking up a thread, indicating a thread, lathe threading, lathe threading setup, threading 101, tubalcain

Id: qyaQqmQxZCg

Length: 41min 53sec (2513 seconds)

Published: Sat Sep 14 2019