Chasing and Repairing Damaged Threads
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- Опубліковано 20 вер 2024
- In this video, I offer a few tips on damaged thread repair techniques and give an "in depth" lesson on lathe setup for chasing threads. Its long, but very detailed. Get comfortable and Take a Look !!
First time I ran a lathe (and got paid for it) was when the normal guy was out sick, Shop owner says "Lerch, can you run a lathe?" I say yes, he says "here, go chase these threads out." and hands me a big expensive looking stud off something. Thankfully the lathe is in a corner and I have a little privacy while I try to figure out how to do what I said I could do but had never done. 15 minutes later and I was spinning the chuck by hand with the half-nuts engaged making sure the tool was following the threads properly and just kissing both sides of the thread. Satisfied I went for it and it turned out great. Next day the normal guy gets an ass chewing because he claimed the lathe was too clapped out to chase threads. I got 'lucky' because my first timid hand powered cut took out all the backlash (and there was a lot) and I literally didn't know to be worried about it! JLerch - Tampa, FL.
Joe it’s MARTIN from ENGLAND
JOE I WOULD LIKE TO KNOW WHAT YOUR COMENT IS ON THIS
Joe I have and do mount the work piece in a collet and center drill the end or nose of the threaded end.
Then remount the work piece in a four jaw chuck.
I keep a length of ground 1/8” dia silver steel with a pointed end witch I mount in my drill chuck in the tail stock ,this is then slid up to the work piece and inserted in the center drilled hole I can then put the Stylus of my clock on the silver steel near the pointed end that is in that is in the center drill hole. It has worked for me on a variety of different jobs.
Once the job is running true I can use a live centre to support the work piece.
Joe I have found you’re videos very enjoyable, as for your presentation you get a 10/10 .
Please keep going,
Martin
"If I touch anything metric, I break out in a rash." I LOL'd
not the wright place to brag about your stupidity.
I cried.
Metric makes more sense then imperial measurements with feet.
Who's feet are we taking into an account ?
People on the dark side of the planet earth were little smarter to come up with a non human part measurement system.
Dude, I'm impressed. I've been been on single and multi spindles since 1979. I only started programming and setting Miyano cnc lathes 4 years ago. I thought I was pretty good at this, but you showed me what I liked most about this trade. You learn something new every day.
Very nice job, if you only knew how much you help us beginners, thank you for your excellent instructions.
Glad to help
The idea of lighting the threads from below makes a huge difference in my dimly lit garage workshop...great tip!
Hello Joe, I really like your explanation when you describe a thread as a train with several carriages !
Cheers from Ingvar, retired service engineer in Sweden (and a hobby shop in my garage among some vintage motorcycles)
Thats important to visualize.
Your back lighting trick is great. I believe it is the same principle as an optical comparator. Using your threading technique of upside down insert on the back side of the thread would get rid of the pucker factor (crashing into the chuck or unthreaded portion of whatever you are chasing) if doing a conventional right hand thread. Your viewers should see your threading video if they haven’t yet. I always appreciate your videos. Southwest Minnesota USA
Hi, Joe, me again (Prof at UT). Every time I run into an interesting challenge, I seem to find your videos to help me out. I was needing to VERY ACCURATELY set back a precision-rifle barrel for rechambering which, of course, requires chasing the original threads so that the new threads match up. This video makes that a cinch! I don't know why I didn't think of making the compound slide parallel with the ways, stopping the machine part-way into the thread, and then adjusting with the compound (while the cross-slide was locked in with the half-nut). Brilliant idea. Thanks again.
Sorry, meant carriage locked in with the half-nut.
For the most accurate positioning, be sure to have some drag on the handwheel when you shut the machine down. i always maintain some drag on the handwheel during threading to eliminate any wander of the pitch.
@@joepie221 Will do. I already 'learned' to hold the cross-slide handle when threading for the same reason. My compound is okay, since I can adjust the tension fairly easily, but the cross-slide can be a problem sometimes. On a side note, do you drink wine? My family and I own a vineyard and winery (in Oregon) and since I am local to you, I would love to bring a few bottles by to show my appreciation for all you do on UA-cam. Just let me know...
Being an old toolmaker I've picked up threads many of times, You did a great job.
Your videos are awesome. I haven’t ran a manual in some years as I moved into CNC but recently got a job running manuals. Watching your videos has snapped me right back into what I had forgotten and more. Thank you, from WA state.
Glad to help
Joe, I had to laugh when you made the comment about breaking out in a rash when you touch anything metric. This is how I feel about imperial stuff.
Great video sir! Thank you.
Actually sharing hard earned knowledge is not as common as one would expect but you do exactly that!
(Athens, Greece).
Your instruction is utterly beyond compare. Thanks for taking the time away from your business to make the videos. Greetings from Gaithersburg, MD.
40 years of knowledge and you have it here........for all to absorb. Your channel and TOT’s videos are great. Thanks for your efforts.....THW. Colorado
*Great* video again, I came here from your comment on Adam’s video; this was very helpful.
One of the first jobs I need to do on my lathe is to clean up come damaged threads on a clamp screw for a friend. (Loose tolerances, so good for a beginner like me.) First I need to actually cut some threads in the first place to learn the absolute basics, but this tutorial has me confident of success already :-) (The part about the slop in the gear train was a real lightbulb realization; I’m sure I would have blown the threads if I hadn’t seen this first!)
Glad you found this helpful.
Once again you mention a bunch of things I never would’ve thought of in a million years. Really interesting as always. 👍
Yeah same here. I get so much more than anyone else out of Joe's videos (cos I know so little about machining) that sometimes I feel guilty. 🤔😂
A++++ as usual. Advanced professor of the internet. Interestingly enough, I have done this a number of times over the years but I still learn when watching your tutorials.
Threading is like two porcupines making love - slow and easy! I like the Joe Pie"s school of higher learning! As a suggestion, could you do a video on cutting a double,or a triple lead thread? I had to do a double lead once and it was kind of cool, and a challenge. I am 73 years young, and still learning. I really enjoy your videos, sir, and look forward to many more. You are never too old to learn something from someone that might be a little bit smarter than you!
I may not be a machinist. But man i learn a lot from almost every single one of your videos. Thanks for taking the time to film and share your knowledge with us!
Thanks for watching.
Thank You Joe. Your content is a pure gold👍 greetings from Poland
From Orlando, Fl, U.S.A Joe; we may be the favorite tourist destination, BUT you're the one we're watching! Excellent! Loved the analogy at the beginning; I've chased successfully before, but your in-depth rationale is flawless Sir. You are the Master. Best wishes!
Thanks.
It is the same old story, measure twice, cut once! And haste makes waste . Im a 70 year old tradesman and am still learning.
BTW i am from Newcastle NSW Australia.
Cheers,
Phil Hopkins
Only the best wishes from Lubbock, Tx, Joe. Everything you teach is world class.
Thank you.
Aftre 20:48 you shut the machine power. I generally like to rotate chuck with hand till the momentum of chuck gives up and matches it with all the slop in gear mechanism. And i like to use a thin sheet steel on the thread to indicate the thread gernal's concentricity. Bye the awesome demonstration keep it up. 👍👍👍
Thanks Joe, I am not a machinist , but a mechanic and fabricator. I love you approch to solving problems Ontario Canada
Hey Joe! ❤️🇺🇸💙 I know this is an older vid, but I just realized I hadn’t seen it yet, so just watched it. And this was FANTASTIC! I love how you showed that you’re watching your timing and alignment all the way in to the half-thousandth and working to just barely graze away the whole surface. Of all your how-tos and “fixing bad behavior” videos… this one was IMO the most fascinating and opened the biggest window on what I call “the mind of a machinist”. Thanks bro!
Glad you enjoyed it.
Pretty amazing.
I searched this out as I need to extend a full depth thread.
I have your lathe in the 15” version.
Not bad for a 50 year old lathe.
Thanks!
Lové you joe it's so nice of you to share your knowledge I'm learning a whole lot from you.Tony from Canada 🇨🇦.
Worked on enough old machines where thread files became my buddies. American guy from Rhode Island. Respects to Tex!
How could you not find value in a lesson like that? Thanks again, Joe.
Good show. I’ve done that many times on a10” Atlas but first I had to take the backlash out from the direction as the apron will go. You’re a true top machinist.
The first time I did this I was a freshman in trade school. 14 years old in 1980, and I had only single pointed a thread twice before. Our school used to take in jobs from local residents or businesses, and this shaft came in with a 9/16"-12 left hand thread that was mangled. It was a really long thread, about 18 inches. My instructor gave me some verbal instructions, and told me not to cut any metal until he approved my setup. I ended up using a follow rest to keep it running true. The first and last time I used a follow rest. Back in those days we had to grind our own tool bits from HSS blanks, which added to the complexity. He checked out my setup and gave me the OK. The part came out great, and I even got a compliment from my instructor. He was a great teacher, and a fair man, but he didn't give out compliments very often. Especially to underclassmen. I did a lot of jobs after that in trade school, and in the 40 years since, but for some reason I always remembered that one.
great balance of board theory backed up with excellent practical demonstration , you have a rare talent Joe . many thanks from Perth Western Australia .
I picked up 2 tips, light under the part and using bluing compound. Sounds like common sense after watching this. I know exactly how it is when you have to pick back up a thread, that first pass can sure make you pucker up! Thanks for the tips Joe, keep them coming! From Kansas USA
Indicating concentricity, just keep the half nut engaged and turn the chuck by hand, this will move the indicator in sync with thread.
I have watched this video a couple of times and I seem to pick up on new things every time. Some times I learn techniques other times it is a nuance on a technique.
Thanks Joe from the bottom of the Texas panhandle.
I for years had trouble with long threads and long nuts. I took pride in being able to make good threads quickly. I was trained old school, making thousands of large shackle pins and big double start square threads for cone clutch actuators on winches. So on my new lathe a tight precise thread would be a nice fit for a few threads and then jam. I had to increase my clearance to get a long nut to spin on. I had checked the pitch using my dro and a stop against a jaw and it measured 6mm on the money in different parts of the leadscrew so the leadscrew being out of tolerance was eliminated. I had cause to service my drop down gears one day and check them. I had a good look at the intermediate gear set, a large gear and a small gear sharing the same axis caught my attention. On close inspection the face of the big gear was out of square to the axis by somewhere around .050". It was wobbling. It was an eureka moment. I dismantles it, machined up the problem face on the drive boss , put it back together. I had cause to make another long thread and nut a short time later and problem was solved. The wobble was effectively advancing and then retarding the lead-screw and as a consequence a nice tight thread was impossible. It was the only thing that bugged me about my lathe. All happy now!
Love when joe pie shows up. I needed to repair a large thread and had no clue where to start and no one to ask how. Stood at the lathe and stared at the part for what seemed like an hour to figure this out on my own. It was one of my prouder moments. 🤔😬
A useful demonstration, reminds me of a job I had where the owner used the wrong loctite grade to hold bearings in a Manx Norton crankcase. It set before the cases where fully together and he beat the crap out of the end of the shaft to release it, he was virtually in tears when I gave it back to him fixed.
Just a point about losing registration, most lathes you can put the speed control into a neutral so you can turn the Chuck but because the lead screw is still directly geared to the spindle all will be well .
I put up a video for you showing my threading tool flat measuring micrometer.
In UK
Hi Joe, Best regard from Canada. I always had a big interest in metalworks and as i will be retiring very soon, my goal is to setup a small metal shop as a hobby. Your videos has been a big part of this, because of the quality information you give.us. Thanks a million time.
Joe- Once again , a super job . explanation , show of patience , super results. Thanks so very much !!! Blessings Paul Kerst USA PENNA.
Another great video! I think your video are great you have a class and then you give a demonstration THAT is what makes your video's so far a head from the others. Calgary Ab Canada.
Hey there, Joe! I'm enjoying your uploads from Hungary. Thanks for another great explanation!
This helped today - i got one of those aftermarket bridgeport power-feed units, but the dial holder threads were simply not deep enough to accommodate the dial lock nut. So I turned a mandrel between centers, mounted the aftermarket unit, and just went through this, a couple of thou at a time, checking the fit until it went on smoothly.
Thanks!
Joe, thank you for these videos. This one really helped correct a 16 tpi thread recently. Turned out perfect!
Aloha Joe, I have never moved the compound to be parallel to the work piece before, but it looks to be a great idea, next time I will. A new learning curve for an old dog, but it should speed thing up!!!! Again thanks for your time in sharing with us.
I have been patiently waiting for a new video....you never disappoint! Still learning everyday...thanks Joe!! New jersey,USA!!!
Great vid joe,I liked the analogy of the train.
In my neck of the woods we called it backlash.
In that non-existant world where friction and clearance dont occur,it would be possible to take a cut on a thread and simply reverse the machine back to the start and the tool would track back perfectly (lol)
However, the backlash would put the tool out of line and destroy the tread and possible the tool.
A graphic demonstration of backlash would be to engage the half nut and rotate the chuck forward, then wind the cross slide till the tool is close to the work.
Scribe a horizontal line on the workpiece level with the tip of the tool.
Then rotate the chuck backwards (by hand) until the carriage just starts to move.
Scribe another line similar to the first one.
Unless you have a perfect (non-existant) machine there will be a gap between the two lines.
This distance is the rotational backlash in the gear train between the chuck and the lead screw.
Cheers,
Phil from OZ
Let me guess.... You work behind s curtain??? 😂🤣
@@brandonlangevin6449 s curtain ???
Your signature line, Phil from Oz. Wizard of Oz.. man behind the curtain..i
@@brandonlangevin6449 Thanks Brandon, ive been called many things , but never "wizard"
Cheers,
Phil from OZ
I’m sure the gun machinist apprentice at work could take the backlash out of the lathe. Anything is possible on overtime
Joe, great video.
I have personally used thread form chasers in the tool post, with the same technique as you have used to dial in the tool position.
Please keep making videos, they are just like catching up with some of the older hands. All that’s missing is a strong cup of tea.
Thanks again
Peter, Bristol UK
Great video! I had to watch again. Turning the compound around IS A BIG DEAL.....GREAT. Thanks....-Tom (Knoxville)
Great clip. I'm a traveling industrial boiler tech. I always carry 3 small hand files for repairing threads. Thought I was the only one...
suggesting to use a single thread measuring wire to check concentricity is a great trick! Much appreciated!
I use snap-on tool thread files and they are my best friend. I started laughing when you showed it because I was thinking about thread files in the beginning of your video. Thank you.
"If I touch anything metric, I break out in a rash." Boom - instant thumbs up. LOL :)
Hi from Swaziland
Been learning a lot from your channel! Thanks
Thanks for all your efforts Joe,
You help educate a lot of people.
Australia, Oz
Perfect Joe... just the way I was taught. Cheers from Perth Australia.
Hi Joe!
This video is a classic. The value of the video is not in it's being timely, but in the teaching it provides.
If I may, a careful examination will reveal that you chose to ignore alignment - the tool holder swivels, introducing errors, so is the compound slide. When you were creeping, you were just about correct at "47". A whole 0.003" before "50". This was not parent because of the "twist" in the setups.
Regardless, he technique is excellent.
I am from the USA, one state up from you.
Thank you for the video!
Simon
I appreciate your comment Simon, but when it comes to machining and more specifically threading, I don't ignore anything. My tool post is always indicated true to both axis of the machine and my threading tool is indicated square as well. There was no error or twist present.
Very cool and educational, thanks for the lesson. - Richard, Spartanburg S.C.
thank you sir, i have always struggled with this operation. the train of thought you have presented makes it very understandable. North east USA
127 country's that is pretty amazing Joe. That is quite a compliment to you
Great tips to keep in mind! Keep the awesome videos coming and huge thank you for the time taken to create them :) Regards, Stellenbosch,South Africa
Thanks. I had over 2 hours of raw footage for this one. It was tough to cut down.
Nice job😃! Had to figure this out the hard way a little while ago. Chipped a tool on an internal square thread with a stop at the end. For a newbie like me it was super frickin scary😬. Thanks to pros like you I was aware of the backlash issue and realigning the tool after sharpening works out great!
So thanks for taking the time to help out newbies like me! 😊
5 mins in and already you've answered a question. I have a 1940s Colchester Triumph round head, and recently had a lot of trouble with threads not quite lining up. I never thought of all the baggy in the lathe drive train, I assumed it was saddle movement, now my saddle assembly is all in bits and if I hadn't seen this, I wouldn't have known what happened if the problem is still there. Every day is a school day
Thanks for the tuition Joe, I am a novice in the UK
Another great video.Your lessons are invaluable to me. I look forward to every one.U.S.A.
You are a true professional, Joe, and I love your videos. Greg from Oakbank, in South Australia.
Greenland here. Love (and learning from) the videos, each one really great! Thanks for sharing.
Thank you Joe. This is something that I’ve tried many times with poor results. Makes so much more sense now.
Ahhh… fond memories of that blue dye some 40 years ago at school - scribing rude things on flat plate 😂 enjoyed the expertise demonstrated - 👍
Great video on how to chase a thread, figured it out on my own some time ago..
((Here is a fun fact.))
Yes you can take the lathe out of gear while threading if it is the spindle speed gears, I do it all the time to change speeds.
You can test this on your lathe by putting the speed selector between gears and turning the spindle
If the lead or feed screw still turns you wont lose timing.
Should work the same on a South Bend belt drive too.
At least on mine the feed direction selector and those after will throw you out of time .
Very applicable to gunsmith operations! I usually am doing this on the inside of female threads.Thanks,
Hi from germany :) Great Video! At least on my machine (Weiler Condor W) the spindle is driven by the motor and the gearing stuff for the compount is driven by the Spindle... This means you can actually "push the train by hand" by just grabbing the chuck. Had to do that once to line up an Internal m30x1.5 thread... to my amazement it actually worked :D
Thanks so much for explaining and recording a practical example of this tedious process!
Thanks, Joe. I learn so much from you every time.
Gold mining in northern BC Canada. Loving your work and knowledge man.
Thank you
I've come to expect a great video from you time after time. Once again, you did not disappoint! Thank you for sharing.
Thank you very much for the compliment. I like to believe my viewers take something from every video.
Joe, this was an excellent video. It's great to see something so well and patiently explained. This was new to me and something I will replicate and practice. Best Regards Sarah (UK)
Great Video I learnt so much and can't wait to practice thread chasing! Chris UK
Thanks again Joe, always listening over here.
Very nice process. Thank you. East Texas. Former Round Rock.
I live just west of Round Rock currently.
Very well explained. Thanks for these videos.
MM from Romania
Great stuff Joe. This something that can always be a big challenge.
One thing I find very useful on my old 11" lathe is use of a spindle handle - that way revolutions can be super slow and allow me to find backlash points etc.
Southern USA. Thank you for a great episode! Please allow me to elaborate briefly: 1. "Time With" means moving at exactly the same rate. "Synchronized" means moving in harmony - Maintaining exact relationship.
You achieve timing with basic machine setup, eliminating slacks, etc. Synchronizing is fine-tuned with the compound.
If the compound is parallel, it has zero effect on depth, 1:1 effect on synchronity. At vertical it is flipped. At 30 degrees it is ½ side, 2x on depth.
Without reciting this I could not wrap my calcified brain around your presentation.
At 26:20 I saw three distinct chips, just as you said. And there they were, sitting there, all nice and neat, on the tool! Nice!
Perfect! You are an excellent instructor! Thank you for taking the time to produce these videos. Ed Hicks SW Mo.
Ji Joe, Thanks for all the knowledge you share! Greetings from Johannesburg South Africa
Very informative, as always. BTW I own a full set of those thread files and they’ve saved the day more than once. Wisconsin, USA
I don’t miss any minute of your channel.
Thanks. I notice your comments.
Threads need fixing all over ther world... Thanks for showing how, Joe! Scotland checking in
Thanks Joe. Learned a lot here that has real practical applications for me. Cheers from New Zealand
Very adequately explained so most anyone can understand
Brilliant as usual. So right about the machine moving on switch off.disengagement. Cheers from Newbury, England
Great video and a couple of things that I would have never have thought about. Thanks ( from Malaysia ).
Great job Joe.
Best regards from the UK.
Thanks for sharing.
Bosted Tap Yo’ bin from the Black Country ay ya, ma mon ?
@@steveallarton98 ar me Mon.
I commented in one of the Tip Blitz videos that it could be useful to have a monitor on the wall behind your machine. Especially if you make videos anyway and have a camera with good close-up capability. Use older folk don't see as well as we used to - Lyle (Mr Pete) sometimes makes tiny errors that we can see on the video, but he could't see directly. This was another example where the benefit of the camera we could see that you were aligned just a couple of thou left of center. so it was no surprise when the tool shaved the left face on the last cut. I use magnetic trays to stop my bits and bobs falling off the mill slide, and I also have a decent Cree LED light mounted to it, which helps my old eyes (I'm 70). One day I'm going to take my own advice and add a camera as a real time microscope.
Well done again. All your videos are insightful and enjoyable to watch. Dave - UK
Dave Crawford South Africa. Awsome tutorial and definately something to put on my to do list. Keep up the great work and teachings you have saved me more than one grey hair. Cheers
It’s been 30;yrs since I chased threads , I think I used the compound set at 29.5 and adj. as though I were threading . I’ve be a small lathe it’s coming next mo. I’m going to try that . I know I’ve lost a lot of my skills but I think with a little practice I’ll get it back