I was thinking how surprising it was, that your video about differential threads seemed to have skipped the opportunity to point out one of the main places that many of my fellow RUclips shop students might discover that they possess and regularly use a great example of differential threads... And then, just as I was about to start typing a comment to that effect, I saw the tap handle you put on screen, right at the end! I actually own an identical one, no less. Anyway, the subject matter of today's class reminds me of when I first figured out the trick to disassembling that style of tap handle. In any case, now I'm hoping to come up with an idea for something I can make or modify to have extra-fine adjustability. Thanks, Mr. Pete!
Interesting use of these in bone surgery. Bones heal better if there is slight compression across the fracture (or deliberate cut). So screws with differential thread pitch are often used, especially in smaller bones such as in feet where not much room for fixation.
I am currently fabricating a telescope mount that requires precision leveling screws. This looks like a perfect application! Thanks. Great presentation, just like all of of yours!
Hi, Lyle I had a former Master Machinist for a machine shop teacher in college. No PhD, just a lifetime of mechanical and machining experiences. We had to cult multi start threads, internal and external, as well as differential screws to his specification, as far as movement per revolution. It was quite a challenge, especially using the old and very clapped-out South Bend lathes that were in the shop. (I cheated the process by using my Le Blond lathe at home) I got way better results than others in my class. About 10 years ago, the college shop was closed down, and I managed to purchase the very large, 16-inch lathe Boyd and Emmes. It was still in perfect shape, and still had the war production tag on it, June of 1941. It is one hell of a large machine, and very heavy. It hadn't aged at all from when I ran it 40+ years before. I am hoping to see you again at the Bar Z Bash in June, I think it might be my last visit there, as my health is failing, I just don't have the endurance I once did, and I am struggling to keep up with the usual farm chores. I really appreciate seeing your continuing progress presenting all the good old days of my High School machine shop teaching. I am kind of sad, that all that great knowledge will never come again in our public schools. Kids these days just don't seem to want to work with their hands, and most all the Industrial Arts shops are now closed. Tim
I do not know if I will make it to California, I have very little endurance and tire out very easily. Young people do not want to work with their hands or get dirty. I watched a Videos the other day, where they were talking about tool and die makers in the auto industry. Almost all those work as overseas as they cannot find anyone interested to learn the trade .
This was great! I’ve been thinking about differential threads in the back of my mind for some time now, as a way to make very fine measurements, to precisely position something, and as an alternative to geared stepper motors for small ranges of motion. This brought it all together for me, very, very well-done as always! (What a beautiful little tool that mini-boring head is, by the way! 👍)
Interesting tidbit: Differential screws depend on the difference in lead so a 1/2-20 screw has a lead of 0.05" but a 1/2-20 LH has a lead of -0.05". When you put these on the same shaft just as you did, the leads still subtract: 0.05 -(-0.05) = 0.10. In other words, they double. This is used in a lot of scissor jack applications such as bumper jacks and some machinist jacks. I think your use of different leads is far cleverer than just using the more obvious LH / RH combination.
They say old dogs can't learn new tricks. But the old dog shop teacher has tought this old dog some information that will be added to the book of tricks. I will have to study up on the math though. Awsome Mr. Pete. In the language of young people you are the GOAT. GREATEST OF ALL TIME. THANKS FOR YOUR EFFORTS.
This video showcases the kind of excellent explanation that Mr. Pete is renowned for- THANK YOU! As a Land Surveyor (hobby machinist).....no doubt my Total Stations utilize differential threads in the horizontal/vertical adjustment screws.
Mr. Pete, you are the best! I've been a machinist and machine designer and somehow this mechanical concept escaped my attention. Needless to say, I will file this away in case I ever need to build myself something that requires extremely fine adjustment.
Right. If you run a single bolt through two nuts, their relative distance won't change as you turn the bolt. And you wouldn't need two different diameters either, because you wouldn't need to feed one thread through a differently threaded hole for assembly. You could just screw the both through the first nut and then start the second nut on it.
Almost 40 years ago we made something like this in Mr Nordofts class at Beloit WI Memorial HS. He was a fine instructor just like you Mr Pete. (He let us sneak out the back door when the bell rang 7th hour)
I built a STEM (scanning tunneling electron microscope) and needed very fine threads for adjustment. I used violin bridge tuners because they were very fine, but now that I've seen this I can easily go back and differentially thread some rod with (already small) watchmaking dies and get even finer results. I actually enjoyed the math part. Thank you Mr. Pete!
Thanks, Mr. Pete, this is something I never paid mind to before! I have seen the reverse used where the threads speed up the movement of the pitch, sometimes used in vises.
@@homemadebuilder113 it's not the same as a turn buckle. This would be one bolt or shaft moving the piece twice the normal distance per revolution. God bless you!
Thank you very much for teaching this! It is just the knowledge I needed to solve an issue with a problematic microscope stage. You always present such interesting topics. I especially appreciate the math examples which make quick use of the information very easy!
genius.... I will be pondering the property behind this for some time. This kind of thing is like magic to me. Not in the sense of a lack of understanding but because of the high degree of cleverness :)
Always interesting stuff Mr. Pete. If one was 18 (1/18=0.0556") and the other 20 (1/20=0.050") the difference would be 0.0556" - 0.050" = 0.0056" or the equivalent of 180 TPI. wow.
Lyle; You mentioned multi-start threads and the difference between pitch and lead. I make custom pens and the cap and nib end of the pens are often either 2-start, 3-start, or 4-start threads. The purpose of these is to multiply the distance that each turn of the cap takes in closing the pen. This allows the pen to close rapidly, but keeps the chance of the threads loosening to a minimum. Keep up the good work, I learn something on each one of your videos!
Here’s an interesting example, Randy - some Cessna aircraft use beautiful, ground four-start threads on their elevator trim jackscrews. As with the pen caps, the object is to convert small rotary motions into large linear translations; it’s also required to have high strength in tension/compression. The four-start threads do that very nicely.
Planning on fabricating a microtome for cutting extremely fine sections of objects to view under a microscope - this could be just the solution I have been seeking! Thank you!
Made no sense to this 71 year old mind until the demo. Wow! That makes it easy to comprehend! The closer the pitches, the finer their difference until they match and there would be no movent. You are still an excellent teacher!!
Absolute gold! Without a lathe and now long in tooth I'll probably never practically apply what I've learned here to anything that I build, but suffice that I'm smarter this eve' than I was over morning coffee.
I had come across differential threads only once in 40 years of machining and fitting on a very old machine tool . It seemed like magic back then and still amazes me today .
Thank you sir for the lesson. As always your show and tell does a great job explaining the idea! I do like introduction of the math along with your functional parts. Teaching shop as you do machining and manufacturing examples is great, these simple parts clearly getting the point across. My only experience with this in my past, that was machining parts for a instrument maker who a shop made parts for. Cheers to you. I spent 40 years, a better part of my career working in many small independent job shops 2-5 years then move on. I only recall seeing parts like that at one shop.
Excellent video on a little known topic. Woodworking hand-screws (two jawed wooden clamps) are usually made with two long steel screws that are right hand thread over half of their length and left hand thread over the rest with corresponding swivel nuts lodged in the jaws so that as the screws are turned the jaws move together or apart quickly.
I love this instructional videos that you make. Hope you make more. I have differential threads on my Veritas handplanes fine adjustments for advancing and retracting the iron
@@mrpete222 looking closer i noticed that on my little block plane the two threads are not differential but, i would say, incremental. In fact the big thread is right handed and the other is the opposite. So they add to each other, i think for space issues
Very interesting video - thanks for posting! This brings to mind the head-to-block studs on my Willys L-134 flathead engine - that have two different thread pitches for another reason. The block side threads are 7/16-14 for maximum root strength, while the head side threads are 7/16-20 for precision while torquing. A common mistake is to replace them with 7/16-14 hex cap screws - which will not stay torqued for very long under use.
I didn't quite understand the point or how it worked exactly until you demonstrated it. It's one of those things that makes perfect sense when someone tells you about it but hard to imagine how anyone came up with the idea.
Mr Pete, one of your best teaching videos. It’s clear that you are and will always be a great teacher. I can still remember my shop classes in 7th grade of junior high school. Your RUclips channel takes me back to those days. Thank you. - George
I was just thinking,yesterday. Grade 8 shop in the afternoons,I learned more during that one year that helped me more,than in anything I learned,straight academic, Grades 1 to 12. I did learn lots in other courses,but without that framework,I would have been lost. Typing,sewing and cooking would have been nice,double entry bookkeeping,other commercial too,but that Grade 8 shop I remember with affection to this day,decades later. Probably why I enjoy watching this so much. Cheers. All the best.
One of those 'AhHA!' things. Once you see it, it seems so trivial, but you realize someone was pretty clever when they dreamed this up. Thanks for sharing.
Thank you Mr Pete. That was some mighty good teaching! Makes me wish I could have been in your class. You already mentioned the example's that I am familiar with.
NOW i Know ! never heard of them. But how good is that, and your Example was a great teaching device. Learn something new every day. Cheers Dave from Australia
I was looking at building a bracket to align two telescopes, so they can be used as high powered binoculars. Optics need serious precision as being 2 thousandths out is perceived by the eye. I came across differential threads when doing research and your 2nd example might be perfect for my purpose but scaled down a little. It needs to be something that can hold itself in place for long periods as well.
Mr Pete, You are an outstanding teacher! What sets you apart from others is that you take the time and effort to make demonstration fixtures that prove your points. I enjoy seeing the proof of your calculations in the demonstrations. Thanks a million!
Hi Mr. Pete, Great video. I always appreciated differential threads in precision instruments. You mentioned the difficulty in making fine pitch threads. Think of the micro screws in watch movements. Some are .25mm pitch or just under .010 inches, or 100 TPI. Cant imagine making those! I have a watch apart now waiting for parts. With my 68 year old eyes I use a microscope and can hardly see the tiny screws unaided!
Design engineer here... I used a differential thread in an assembly fixture to precisely align parts under a microscope. I actually went much smaller, drilling and tapping a #10-32 thumbscrew with a #4-40 through hole. Six thousandths and change per revolution (with off-the-shelf tools!) The 4-40 stud was fixed, the 10-32 thumbscrew was the operator input, and the nut threaded on the thumbscrew was the actuator.
You have shown me something that blew my mind. I believe that this thing could be used very well in the machining industry and the reloading and firearms industry. I’ve been in the light line and heavy line repair industry for 30+ years and never saw one in use but I’ve seen some laying around the shop that were used and damaged and never knew what they were called or for. Thank you Mr Pete!
We use those daily on extrusion dies, it sets our gap in the die to maintain consistent adhesive coating. The gap is set using differential bolts of various sizes depending on the die being used. An example of one of our bolts, has threads of 3/8-26 & 7/16-20 which comes out to .012" per revolution. Have had to make a few of those in a pinch to get us thru the run. We mostly order them from a supplier due to the cost of labor in house vs. the amount of bolts we go thru.
Always enjoy your videos. General Electric CF6-80A accessory gearbox thrust link uses differential threads for adjusting length, except one is RH and the other is LH.
This is the best basic demonstration of the concept I have seen. 2 threads the same pitch (such as 1/4-20 and 1/2-20) would provide no movement per rotation. I had to think about that but it made the concept more clear to me.
If 2 threads of the same pitch produced a movement, then threads wouldn't work at all, because a single thread is indistinguishable from 2 threads of the same pitch + diameter. Simply running a nut onto a bolt would split the nut in half!
@@cogentdynamics Yeah, exactly. It must be the case that 2 threads of the same pitch have no differential movement, otherwise you wouldn't be able to thread a nut on to a thread, because the front of the nut would be jacked away from the rear of the nut!
Thank you Mr. Pete, for another great video. I've been a machinist for over 40 years and never head of a Differential thread. Thank you for sharing your knowledge.
This video proves that in the 17th and 18th century, brilliant engineers and craftsmen had skills that are Really amazing, ALL without the Internet!! All they needed was to wait a little while for the Dummies to Catch up!!!!
Lyle, your pink paint reminds me. Back in the 70's, my dad made bolo ties, and the ends of the cord had sexogonal ends which he painted red, white and blue. He couldn't find small enough containers of paint for that, so he used nail polish. It worked out well. The paint held up nicely.
Thanks for the video. Not being a machinist, I had never heard of differential threads. However, in many of my precision tools and instruments I have used in my career, this is exactly the type threads used. Quite interesting to me! Thanks again.
Machinist 30 years, never actually realized how important this concept was. Mr. Pete, Thank you for posting!!
😄😄
Yes Sir, same here. That's why Mr. Pete is our RUclips shop teacher even at our age (1951).
Art from Ohio
I was thinking how surprising it was, that your video about differential threads seemed to have skipped the opportunity to point out one of the main places that many of my fellow RUclips shop students might discover that they possess and regularly use a great example of differential threads... And then, just as I was about to start typing a comment to that effect, I saw the tap handle you put on screen, right at the end! I actually own an identical one, no less.
Anyway, the subject matter of today's class reminds me of when I first figured out the trick to disassembling that style of tap handle.
In any case, now I'm hoping to come up with an idea for something I can make or modify to have extra-fine adjustability.
Thanks, Mr. Pete!
You're truly awesome mr Pete,I've learnt so much from your amazing videos.
Your experience and knowledge is incredible.
I appreciate that!
I love all these 'clevernesses' that early machinists and engineers came up with. Quite genius.
Interesting use of these in bone surgery. Bones heal better if there is slight compression across the fracture (or deliberate cut). So screws with differential thread pitch are often used, especially in smaller bones such as in feet where not much room for fixation.
Excellent video explaining differential threads, Tubalcain.
Very important information for anyone trying to fabricate a fine movement or adjustment.
Many thanks!
I am currently fabricating a telescope mount that requires precision leveling screws. This looks like a perfect application! Thanks. Great presentation, just like all of of yours!
👍👍
Hi, Lyle
I had a former Master Machinist for a machine shop teacher in college. No PhD, just a lifetime of mechanical and machining experiences.
We had to cult multi start threads, internal and external, as well as differential screws to his specification, as far as movement per revolution.
It was quite a challenge, especially using the old and very clapped-out South Bend lathes that were in the shop. (I cheated the process by using my Le Blond lathe at home) I got way better results than others in my class.
About 10 years ago, the college shop was closed down, and I managed to purchase the very large, 16-inch lathe Boyd and Emmes. It was still in perfect shape, and still had the war production tag on it, June of 1941. It is one hell of a large machine, and very heavy. It hadn't aged at all from when I ran it 40+ years before.
I am hoping to see you again at the Bar Z Bash in June, I think it might be my last visit there, as my health is failing, I just don't have the endurance I once did, and I am struggling to keep up with the usual farm chores.
I really appreciate seeing your continuing progress presenting all the good old days of my High School machine shop teaching.
I am kind of sad, that all that great knowledge will never come again in our public schools.
Kids these days just don't seem to want to work with their hands, and most all the Industrial Arts shops are now closed.
Tim
I do not know if I will make it to California, I have very little endurance and tire out very easily.
Young people do not want to work with their hands or get dirty. I watched a Videos the other day, where they were talking about tool and die makers in the auto industry. Almost all those work as overseas as they cannot find anyone interested to learn the trade .
This was great! I’ve been thinking about differential threads in the back of my mind for some time now, as a way to make very fine measurements, to precisely position something, and as an alternative to geared stepper motors for small ranges of motion. This brought it all together for me, very, very well-done as always!
(What a beautiful little tool that mini-boring head is, by the way! 👍)
👍👍
Interesting tidbit: Differential screws depend on the difference in lead so a 1/2-20 screw has a lead of 0.05" but a 1/2-20 LH has a lead of -0.05". When you put these on the same shaft just as you did, the leads still subtract: 0.05 -(-0.05) = 0.10. In other words, they double. This is used in a lot of scissor jack applications such as bumper jacks and some machinist jacks. I think your use of different leads is far cleverer than just using the more obvious LH / RH combination.
Thanks
Turnbuckle or a woodworking hand-screw clamp.
👍I always thought one had to be a left hand to subtract the leads. Thanks for sharing.
I’ve read about these before and knew that they were used in micrometers, but after seeing this I understand how they work. thanks!
Good Morning!
I once again learned something, you make the world a better place from your home shop!
Thanks!
Thanks
Lyle, you've been holding out on us Sir. More pearls of wisdom from our favorite shop teacher. Thank you Sir.
Thumbs up Mr. Pete. What a clever mechanism, thanks for sharing.
Thanks 👍
Mr. Pete, you provide a true service to mankind. Thank you!
Thank you kindly
@@mrpete222 The comment was, indeed, most sincere. Thank you so much for the reply :-)
They say old dogs can't learn new tricks. But the old dog shop teacher has tought this old dog some information that will be added to the book of tricks. I will have to study up on the math though. Awsome Mr. Pete. In the language of young people you are the GOAT. GREATEST OF ALL TIME. THANKS FOR YOUR EFFORTS.
Thank you very much
This looks like a great way to get precise movement on devices that need a large beefy thread to withstand high forces.
This video showcases the kind of excellent explanation that Mr. Pete is renowned for- THANK YOU!
As a Land Surveyor (hobby machinist).....no doubt my Total Stations utilize differential threads in the horizontal/vertical adjustment screws.
Thank you very much for the fine complement
Somehow I had never heard of differential threads until now. My mind is entirely blown at how clever this is. So many applications! 🤯
👍👍👍
Very nice content. First time someone explained it to me.
Karl Holtey uses differential threads for the super fine adjusters on his superior wood planes. Thank you for sharing this great demonstration.
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Very interesting Mr Pete
they say you can learn something every day
I certainly did
thanks awsomeley
Great Video! I have worked hands on my whole life (76 years old) and I didn't know this.
Mechanic and machinist nearly 40 years and this is new to me, I really enjoyed learning this ........ thank you.
😄😄
Mr. Pete, you are the best! I've been a machinist and machine designer and somehow this mechanical concept escaped my attention. Needless to say, I will file this away in case I ever need to build myself something that requires extremely fine adjustment.
👍👍👍👍👍👍👍
Very informative and interesting! Thank you for doing this type of video!!
Everyone has already stated my response! Excellent explanation. The comments on this video are very good too.
Awesome, thank you!
Great demo and explanation, Nice.
Glad you liked it!
That was mind blowing. I didn't understand at first, then I realized if the pitch/lead was the same in both holes, the block wouldn't move.
Right. If you run a single bolt through two nuts, their relative distance won't change as you turn the bolt. And you wouldn't need two different diameters either, because you wouldn't need to feed one thread through a differently threaded hole for assembly. You could just screw the both through the first nut and then start the second nut on it.
This was extremely interesting to me! Thank you for teaching me about differential threads. Something I never knew about and it's rather fascinating.
Almost 40 years ago we made something like this in Mr Nordofts class at Beloit WI Memorial HS. He was a fine instructor just like you Mr Pete. (He let us sneak out the back door when the bell rang 7th hour)
👍😄😄😄😄
I learned something new today. Very cool.
I had to watch this video twice to wrap my head around how this worked but I see it now. Very interesting.
👍👍
I built a STEM (scanning tunneling electron microscope) and needed very fine threads for adjustment. I used violin bridge tuners because they were very fine, but now that I've seen this I can easily go back and differentially thread some rod with (already small) watchmaking dies and get even finer results. I actually enjoyed the math part. Thank you Mr. Pete!
👍👍👍👍
Thanks, Mr. Pete, this is something I never paid mind to before! I have seen the reverse used where the threads speed up the movement of the pitch, sometimes used in vises.
I wondered this while watching. So would the setup just be reversed? The smaller thread to the rear? Or is the configuration completely different?
@@AdamA-pm3yn this is like a turnbuckle
@@homemadebuilder113 it's not the same as a turn buckle. This would be one bolt or shaft moving the piece twice the normal distance per revolution.
God bless you!
A true turnbuckle does move double the distance in either direction when rotated.
You sure they aren't just two-start threads?
you
you're students were very lucky to have such a great shop teacher
Thank you! 😃
Thank you very much for teaching this! It is just the knowledge I needed to solve an issue with a problematic microscope stage. You always present such interesting topics. I especially appreciate the math examples which make quick use of the information very easy!
wow i never heard of it before . this is great. makes sense on a boring mill . i never thought about how they get such fine movement .
HI, I'm an old dog and I just learned a new trick! very cool
Rich
genius.... I will be pondering the property behind this for some time. This kind of thing is like magic to me. Not in the sense of a lack of understanding but because of the high degree of cleverness :)
👍👍
Wow, you’ve shown me something again. Thanks for doing this. All these years and I learned something new today.
Glad to hear it!
I learned something today. That’s themost clever idea and design I’ve ever seen in quite a while. Really interesting 🙂👍
👍👍
Hi Mr. Pete "The Godfather of shop", The lead screw in my little unimat lathe is a differential. One part left hand.
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Always interesting stuff Mr. Pete. If one was 18 (1/18=0.0556") and the other 20 (1/20=0.050") the difference would be 0.0556" - 0.050" = 0.0056" or the equivalent of 180 TPI. wow.
Stumbled upon this randomly, but very happy I did. Reminds me a lot of the concept of mechanical advantage.
Yes
Thanks for putting the out for everyone--a great student project!
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Mr Pete .A big thank you for the inspiration videos. I very much enjoy the content
Lyle; You mentioned multi-start threads and the difference between pitch and lead. I make custom pens and the cap and nib end of the pens are often either 2-start, 3-start, or 4-start threads. The purpose of these is to multiply the distance that each turn of the cap takes in closing the pen. This allows the pen to close rapidly, but keeps the chance of the threads loosening to a minimum. Keep up the good work, I learn something on each one of your videos!
👍👍
Here’s an interesting example, Randy - some Cessna aircraft use beautiful, ground four-start threads on their elevator trim jackscrews. As with the pen caps, the object is to convert small rotary motions into large linear translations; it’s also required to have high strength in tension/compression. The four-start threads do that very nicely.
Like your addition here!
Planning on fabricating a microtome for cutting extremely fine sections of objects to view under a microscope - this could be just the solution I have been seeking! Thank you!
I learned something today. Thanks Mrpete!
Made no sense to this 71 year old mind until the demo. Wow! That makes it easy to comprehend! The closer the pitches, the finer their difference until they match and there would be no movent. You are still an excellent teacher!!
Absolute gold! Without a lathe and now long in tooth I'll probably never practically apply what I've learned here to anything that I build, but suffice that I'm smarter this eve' than I was over morning coffee.
😄👍
I had come across differential threads only once in 40 years of machining and fitting on a very old machine tool . It seemed like magic back then and still amazes me today .
👍👍
Thank you sir for the lesson. As always your show and tell does a great job explaining the idea! I do like introduction of the math along with your functional parts. Teaching shop as you do machining and manufacturing examples is great, these simple parts clearly getting the point across. My only experience with this in my past, that was machining parts for a instrument maker who a shop made parts for. Cheers to you. I spent 40 years, a better part of my career working in many small independent job shops 2-5 years then move on. I only recall seeing parts like that at one shop.
Thanks for watching. I’m glad you like the video.
That's pretty kick ass Mr Pete, love it when you pop up in my suggested. Always learn something new from you, God bless
👍👍
Excellent video on a little known topic. Woodworking hand-screws (two jawed wooden clamps) are usually made with two long steel screws that are right hand thread over half of their length and left hand thread over the rest with corresponding swivel nuts lodged in the jaws so that as the screws are turned the jaws move together or apart quickly.
I love this instructional videos that you make. Hope you make more. I have differential threads on my Veritas handplanes fine adjustments for advancing and retracting the iron
👍👍
@@mrpete222 looking closer i noticed that on my little block plane the two threads are not differential but, i would say, incremental. In fact the big thread is right handed and the other is the opposite. So they add to each other, i think for space issues
Very interesting video - thanks for posting! This brings to mind the head-to-block studs on my Willys L-134 flathead engine - that have two different thread pitches for another reason. The block side threads are 7/16-14 for maximum root strength, while the head side threads are 7/16-20 for precision while torquing. A common mistake is to replace them with 7/16-14 hex cap screws - which will not stay torqued for very long under use.
Once again, I learned a lot from you. Thanks Mr. Pete!
Glad to hear it!
Very cool, thanks for sharing Mr Pete, I did not know about this kind of thread.
Thank you for making the demonstration model too!
I didn't quite understand the point or how it worked exactly until you demonstrated it. It's one of those things that makes perfect sense when someone tells you about it but hard to imagine how anyone came up with the idea.
Fascinating. I’ve never known this property before. Thanks.
never heard of this before. thanks for making this video! great fact
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Today I learned something that I thought I already new, but clearly didn't. Teaching at it's best. Top man.
I appreciate that!
Mr Pete, one of your best teaching videos. It’s clear that you are and will always be a great teacher. I can still remember my shop classes in 7th grade of junior high school. Your RUclips channel takes me back to those days. Thank you. - George
Thank you, George, you just made my day
I was just thinking,yesterday. Grade 8 shop in the afternoons,I learned more during that one year that helped me more,than in anything I learned,straight academic, Grades 1 to 12. I did learn lots in other courses,but without that framework,I would have been lost.
Typing,sewing and cooking would have been nice,double entry bookkeeping,other commercial too,but that Grade 8 shop I remember with affection to this day,decades later.
Probably why I enjoy watching this so much.
Cheers. All the best.
Thank You Lyle... this is fascinating and it does get my imagination working. Much appreciated....TM
One of those 'AhHA!' things. Once you see it, it seems so trivial, but you realize someone was pretty clever when they dreamed this up. Thanks for sharing.
👍👍
wow, very interesting. could be useful to keep in the back of my brain, and the math is simple to boot!
Hey Mr. Pete, I noticed with the nice little boring head that the larger thread is the finer one and the smaller is considerably coarser. Very Cool.
Thank you Mr Pete. That was some mighty good teaching! Makes me wish I could have been in your class. You already mentioned the example's that I am familiar with.
😄😄
Excellent video. I’ve been in the trade since 1999 and I learned something today.
Great to hear!
Pretty interesting! Doesn't matter how many years I got machining, I always learn something from you!
Great to hear!
That was really interesting. Keep it comming. Just love to watch and learn from your videos. Thank you.
Thanks
NOW i Know ! never heard of them. But how good is that, and your Example was a great teaching device. Learn something new every day. Cheers Dave from Australia
Glad it was helpful!
I was looking at building a bracket to align two telescopes, so they can be used as high powered binoculars. Optics need serious precision as being 2 thousandths out is perceived by the eye. I came across differential threads when doing research and your 2nd example might be perfect for my purpose but scaled down a little. It needs to be something that can hold itself in place for long periods as well.
👍👍
Mr Pete,
You are an outstanding teacher! What sets you apart from others is that you take the time and effort to make demonstration fixtures that prove your points. I enjoy seeing the proof of your calculations in the demonstrations. Thanks a million!
You are very welcome
Hi Mr. Pete, Great video. I always appreciated differential threads in precision instruments. You mentioned the difficulty in making fine pitch threads. Think of the micro screws in watch movements. Some are .25mm pitch or just under .010 inches, or 100 TPI. Cant imagine making those! I have a watch apart now waiting for parts. With my 68 year old eyes I use a microscope and can hardly see the tiny screws unaided!
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I never thought about how this was done before now. Good video thanks.
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Design engineer here... I used a differential thread in an assembly fixture to precisely align parts under a microscope. I actually went much smaller, drilling and tapping a #10-32 thumbscrew with a #4-40 through hole. Six thousandths and change per revolution (with off-the-shelf tools!) The 4-40 stud was fixed, the 10-32 thumbscrew was the operator input, and the nut threaded on the thumbscrew was the actuator.
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You have shown me something that blew my mind. I believe that this thing could be used very well in the machining industry and the reloading and firearms industry. I’ve been in the light line and heavy line repair industry for 30+ years and never saw one in use but I’ve seen some laying around the shop that were used and damaged and never knew what they were called or for. Thank you Mr Pete!
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Just like the telescoping legs in a steady rest..... Excellent explanation!!
Mr. Pete, that is absolutely cool and I never knew about this. (I'm an electronics guy).
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That’s a great explanation and demonstration. Thanks.
We use those daily on extrusion dies, it sets our gap in the die to maintain consistent adhesive coating. The gap is set using differential bolts of various sizes depending on the die being used. An example of one of our bolts, has threads of 3/8-26 & 7/16-20 which comes out to .012" per revolution. Have had to make a few of those in a pinch to get us thru the run. We mostly order them from a supplier due to the cost of labor in house vs. the amount of bolts we go thru.
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Always enjoy your videos. General Electric CF6-80A accessory gearbox thrust link uses differential threads for adjusting length, except one is RH and the other is LH.
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Wow. Love to learn something! I never had even heard of this concept. Thanks for the video Mr. Pete!
Any time!
This is the best basic demonstration of the concept I have seen. 2 threads the same pitch (such as 1/4-20 and 1/2-20) would provide no movement per rotation. I had to think about that but it made the concept more clear to me.
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If 2 threads of the same pitch produced a movement, then threads wouldn't work at all, because a single thread is indistinguishable from 2 threads of the same pitch + diameter. Simply running a nut onto a bolt would split the nut in half!
@@jsincoherency I think I’m still confused. 20-20=0 …. Here I was content for a couple minutes.
@@cogentdynamics Yeah, exactly. It must be the case that 2 threads of the same pitch have no differential movement, otherwise you wouldn't be able to thread a nut on to a thread, because the front of the nut would be jacked away from the rear of the nut!
I think this concept runs with outside and inside thread, then the block will move but in the opposite direction.
Great video. I wish I knew about differential threads a long time ago. Its a very simple way of getting very preise movement.
Thanks for posting. It is enjoyable to see it explained so simply.
Thank you Mr. Pete, for another great video. I've been a machinist for over 40 years and never head of a Differential thread. Thank you for sharing your knowledge.
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Very interesting and informative! Thanks for the excellent presentation!
Glad you enjoyed it!
It is great to learn new applications for something as simple as threads, will definitely use it in future!
This video proves that in the 17th and 18th century, brilliant engineers and craftsmen had skills that are Really amazing, ALL without the Internet!!
All they needed was to wait a little while for the Dummies to Catch up!!!!
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This is very interesting. I did not know about these threads, but I probably have them on machines or equipment in the shop. Thanks for sharing.
Lyle, your pink paint reminds me. Back in the 70's, my dad made bolo ties, and the ends of the cord had sexogonal ends which he painted red, white and blue. He couldn't find small enough containers of paint for that, so he used nail polish. It worked out well. The paint held up nicely.
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Excellent demonstration and explanation.
I'd actually never heard of differential threads before, but this could be very relevant to my work. Thanks for sharing!
Glad it was helpful!
Mr Pete, such a clever idea so eloquently explained and demonstrated, thank you!
Thanks
Thanks for teaching me a new addition for my bag of tricks!
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Thanks for the video. Not being a machinist, I had never heard of differential threads. However, in many of my precision tools and instruments I have used in my career, this is exactly the type threads used. Quite interesting to me! Thanks again.
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Man! This is useful information. I have a couple homemade jigs that would benefit from this application.
Thank you sir!