Thanks for this video Keith, I relied upon it to do internal acme threading for the elevating screw base on a civil war cannon that I'm building. Nice to see you at Florida flywheelers again.
Nice work. Thanks for making the video. I have yet to try to cut an Acme thread internal or external. As I recall the Coyote was always using Acme gadgets in his effort to catch the Roadrunner. Don’t know if that one inch drill bit you were using was a taper shank drill or not, but one trick is to clamp a lathe dog onto the drill shank at the front face of the tailstock ram and rest the lathe dog tang on the compound, prevents the drill from spinning.
Note on drilling copper alloys, you could blunt the drill bit cutting edge to neutral vs the standard positive rake, this will prevent the bit being pulled out of quill. Cheers
I did almost the exact same job today. Made the nuts first...8TPI. Then it just dawned on me, that was I meant to have the compound set at 14.5 deg or should have I just plunged? I did use the angled compound and then came here this evening to see what you have done or how you tackled the same job. The dial gauge for the thread depth is a good idea yet also a couple of quick trig calcs will determine that the ratio on the X axis at 14.5 deg using the compound is 1.032888. ie thread depth of .072 becomes just over .074 on the compound dial. Very much enjoy your style Keith and I've picked up on so many little tips from your videos... All so very well done and thanks from all of us out here... I would have stayed awake wondering all night if I'd done today's threading right otherwise.
We used the term "single point" as referring to this type of thread cutting. I did hundreds of ACME , Square, Buttress, and traditional 60 degree threading for industrial presses. Its quite unsettling how a steep profile thread can go from too tight to loosey goosey, in one light pass....good luck to you.......PS: double the pitch, cut a thread engaging halfnut on 1 or 3, cut another thread on 2 , 4. Viola' double lead. Twice the travel, same amount of wear surface.
HMM a table that has a crank and gets longer by cranking, I've seen plenty of those, usually with the good guy strapped to them while the bad guys henchman is cranking the handle..... LOL
One thing I appreciate and have always seen on this channel are useful videos. Never have I ever seen a pointless video here. It looks like it's nearly always a success, and even a failure would have tremendous instructive value.
What is it with internet trolls? All the comments about how this is overkill...do you KNOW what sort of table this is? Does it matter to you if someone wanted something to those specs? Maybe the reason for acme threads is smoothness and reduced backlash, maybe it just doesn't matter to you.
I think that I'm not too aggressive in threading cuts but I'd be taking .015 a couple of times, then .010 a couple of times before dropping to .005. Nibbling at the work is a great way to wear out a tool before the job is done (as I've proved myself a number of times)
I've got a J.H. Williams bulletin from the 1940's for their threading tool holders. It says that to cut internal threads with the compound swung to the right... like you do for external threads. The bulletin also says that 90 deg. feed in is to be avoided as well. I've seen some recommend straight in-feed as giving just as good a result (with carbide inserts perhaps?). I actually cut internal threads as shown by Keith, but the next time I do cut them I will try the Williams recommendation and see how it works.
I guess if you think the tooling engineers at J.H. Williams had no clue how to cut threads after 30 years experience, you must be smarter than they were.
I was taught to always set your compound so that you are only cutting on the leading face of the thread doing the cutting. While I have to agree that with carbide tooling, it probably does not matter as much, I still think it is good practice. If you just cram the tool into straight on, you are actually cutting on both the front and back of the V, and it makes sense to me that you want to cut on the leading edge and not be dragging on the back.
Keith, I'll send you a copy of the Williams bulletin. The bulletin says that there is better chip formation following their suggestion. Like you, I was taught to swing the compound to the left when threading internally. I had to read it several times to make sure I correctly understood their recommendation. The advantage to the Williams suggestion is that the compound is not likely to have interference with something like a casting that was being threaded.
It's really surprising to see that much deflection on the spring cut passes. I knew there was some, but I wouldn't have guessed that much. Thanks for sharing.
I think his surprise may have been in seeing so much deflection on the tool post where if the indicator were on the boring bar the deflection would have been expected.
on that first internal cut where he sets zero, cut to full thread depth and mark zero, then make a cut through hole at half depth come out and set to your zero or full depth and finish it.
Don't know if you've noticed, but your dial indicator is getting a little sticky. At 17:49 you moved the compound and it came clear for a moment before clicking back against the compound. I'd guess it's probably not a huge problem at this point, but may be something to keep in mind, in case it starts getting worse.
Keith, a question... Could backlash be a contributing factor to the "spring" in this particular setup? The depth of cut is being set by retracting the compound and the thread face of the nut away from machine center is engaged. Would it be stiffer to retract past the the set point then move forward to the desired position? That way the push from the pressure is against the engaged face of the nut thread.
No, never predrill if your machine has enough power. Using any size of predrill will just increase shatter and burn the corners of your drill. There is no point arguing, this is easy to try, first drill with a predrilled hole and then same without predrilling (or better in reverse order, so that you don't ruin your drill in first hole) and listen to the sound of drilling and inspect surface quality and condition of your drill. Adequate amount of cooling is of course important in both cases.
I was concerned about the .0725 cut, at first I thought it should be 1/2 that when read on the dial. At least on my SB lathe dial cutting on the radius 10ths would actually move a dial indicator 5ths. I couldn't read the dial indicator in the video so depending on the lathe's dial either it went the full 72.5 or 1/2 that.
The full 0.0725". It seems like a lot, but if you do the math, that is the correct depth for Acme at 8 TPI. The outside diameter of the shaft is 1-1/8" and the root of the thread is 1". Take 1/8" (0.125") and divide in half (threads on both sides) and you get 0.0625". Add 0.010" for clearance, and you get 0.0725".
Missed the 1/2 math that you already took. Really figured you would not have made that, unless your lathe dial had a different calibration. I think most compound dials have have the 2:1 ratio, but maybe not all. :-)
The fact that he used a drill for final size means he did not bother to measure and close was good enough, not a normal or typical approach but apparently ok in this case.
@@TroubledTimes2024 good lord a three year old video, i cant remember the context , there have been so many since, but i guess my comment was about the apparent discontinuity between length and diameter tolerances. Agreed sometimes near enough is quite good enough.
Nice. Maybe what I am seeing is a camera trick, but it seemed that the thread dial was jumpy or sticking and not turning smooth. Is there a lot of backlash in that thread dial, or is it sticky? OR, is it just the video, my internet connection, etc... ? :-D.
Ah, I thought I was seeing things. I have a Logan that had a funky thread dial, the drive gear was mangled and didn't engage properly with the lead screw and it did the same thing. Replacement gear fixed it right up. Hope it is an easy fix for you.
John F, Standard way to cut a LH screw is to just run the leadscrew "backwards", not the lathe, and start from the inside and run outwards, not very confusing to my eyes. Much more confusing cutting a RH thread with the lathe running backwards, but once mastered it's much better way...
Bill Moore - if your lathe has a quick change gearbox you set that up for your desired threads per inch. Without a quick change gearbox, you set up the proper change gears for your desired thread.
Speaking of the drill bit spinning, why do bits (all or most) have circular shanks? It seems like square or hexagonal or three-sided or anything except circular would solve this spinning problem, yes? I know this one was a taper, but why not just make it non-circular so it could not spin?
JL Software - just a guess, but I would bet that 1 inch drill that Keith was using was a taper shank drill. Probably dug in and slipped because it is sharp and copper, brass and bronze are grabby materials.
Hello there KEITH Nice train of thought to follow through on an intended project. Call it "Sequence of Ops" prior to ..... May U let us have that Engineers Web site details please. Can't access it. Might need that in the foreseeable future, IA Thanks for showing and sharing ATB] aRM
If you use the email address that I show at the start of my videos when my name pops up on screen, you should be able to reach me. I get tons of emails on it every day so I know it works.....
I agree squaring off the lip is a good tip but the fundamental issue here is the overly large "pilot" hole. If the pilot hole diameter was close to the drill web thickness there would be little tendency to self drill. Step drilling in general is a poor strategy that is excusable on wimpy machines but pointless on such a robust machine as used here. My other issue is rather than relying on the drill cutting an accurately centered diameter it would be much better to bore to the final minor diameter and certainly not reversing the blank between minor diameter cutting and threading.
Acme threads for this is bit of overkill.. but you know that. For his project a multiple start Unified National thread would be better and easier to make. A 16 tpi four start thread would do the trick (Lathe set for 4 tpi with 16 tpi profile).
Unless the dining room tabletop is 2" thick steel plate, I don't think it would too hard to push the table leaves apart. You do know why you would use a multi-start thread, don't you? ..So you won't be turning a crank all day to get the leaves apart.
chris0tube True, but cranking that little gear in the center 4X per inch of separation (8TPI but on left and right hand threads like a turnbuckle) may get tiresome if he needs to open the table often. Maybe it’s electric so no biggie...?
My motto - if it is worth doing, it is worth overdoing! Seriously, the guy who I am doing this for wanted Acme threads so that is what he got. And at the end of the day, it will work just fine so I did not see any reason in changing his mind.
Easier, yes, but I hated to spend the money on both a right and left hand tap to be used one time. And I could knock them off on the lathe in much less time than it would take to ship the tools to me.
The video ended unexpectedly, usually Keith has a little outro talking about continuing the project. I assume he just filmed the whole thing and didn't film an interlude?
That would be correct. My original plan was to do both the internal and external threads in one video, but when I started editing, I realized it needed to be broken into two episodes. And due to time constraints, I did not have time to go back to the shop to shoot that interlude.... What can I say, my productions are not made in Hollywood.....
Your productions are better than anything in hollywood, I only mentioned because it wasn't like your normal video intro's and outro's. Always appreciate your videos!
I'd love to know what sort of table needs anything close to 1 1/8"-8 acme threaded rods for moving the leaves. Great video, but something tells me this is beyond overkill. And I say that as someone who generally over-builds his projects.
Does it "need" acme? Probably not, but he does want a course lead on it so that he is not having to crank the table all day long to get it to move. With the left and right hand threads at 8TPI, four revolutions of the screw will move the table 1". With this course thread, Acme kind of makes sense.
Perhaps I should copyright that "music" so that everybody else has to give me royalties for including their machine "music" in the background of their videos.....
Thanks for this video Keith, I relied upon it to do internal acme threading for the elevating screw base on a civil war cannon that I'm building.
Nice to see you at Florida flywheelers again.
I should have listened to my dad all them years ago and went to school to be a machinist! Nice work!
Thanks for sharing Keith, I often use the "Dash board gauge" myself
Nice video!
Nice work. Thanks for making the video. I have yet to try to cut an Acme thread internal or external. As I recall the Coyote was always using Acme gadgets in his effort to catch the Roadrunner. Don’t know if that one inch drill bit you were using was a taper shank drill or not, but one trick is to clamp a lathe dog onto the drill shank at the front face of the tailstock ram and rest the lathe dog tang on the compound, prevents the drill from spinning.
Note on drilling copper alloys, you could blunt the drill bit cutting edge to neutral vs the standard positive rake, this will prevent the bit being pulled out of quill.
Cheers
I did almost the exact same job today. Made the nuts first...8TPI. Then it just dawned on me, that was I meant to have the compound set at 14.5 deg or should have I just plunged? I did use the angled compound and then came here this evening to see what you have done or how you tackled the same job. The dial gauge for the thread depth is a good idea yet also a couple of quick trig calcs will determine that the ratio on the X axis at 14.5 deg using the compound is 1.032888. ie thread depth of .072 becomes just over .074 on the compound dial. Very much enjoy your style Keith and I've picked up on so many little tips from your videos... All so very well done and thanks from all of us out here... I would have stayed awake wondering all night if I'd done today's threading right otherwise.
We used the term "single point" as referring to this type of thread cutting.
I did hundreds of ACME , Square, Buttress, and traditional 60 degree threading for industrial presses. Its quite unsettling how a steep profile thread can go from too tight to loosey goosey, in one light pass....good luck to you.......PS: double the pitch, cut a thread engaging halfnut on 1 or 3, cut another thread on 2 , 4. Viola' double lead. Twice the travel, same amount of wear surface.
Nicely done Keith!
ATB, Robin
If Robin approves, I must be doing OK! Not like some of the haters that seem to be commenting here lately....
Good tip using the dial gauge. Thanks
HMM a table that has a crank and gets longer by cranking, I've seen plenty of those, usually with the good guy strapped to them while the bad guys henchman is cranking the handle..... LOL
Gracias por sus videos me enseñan muchísimo que Dios lo siga bendiciendo
Well done, thanks for the video.
I did that with press fit bushings. I was close . And 2 extra no adjustment passes to take it to size.
that should work great ! ACME is a tough act to follow ..LOL.. THUMBS UP !
One thing I appreciate and have always seen on this channel are useful videos.
Never have I ever seen a pointless video here. It looks like it's nearly always a success, and even a failure would have tremendous instructive value.
What is it with internet trolls? All the comments about how this is overkill...do you KNOW what sort of table this is? Does it matter to you if someone wanted something to those specs?
Maybe the reason for acme threads is smoothness and reduced backlash, maybe it just doesn't matter to you.
I think that I'm not too aggressive in threading cuts but I'd be taking .015 a couple of times, then .010 a couple of times before dropping to .005. Nibbling at the work is a great way to wear out a tool before the job is done (as I've proved myself a number of times)
Nice camera work- would like to see how you set up your cameras. Your dial indicator is a bit sticky.
I've got a J.H. Williams bulletin from the 1940's for their threading tool holders. It says that to cut internal threads with the compound swung to the right... like you do for external threads. The bulletin also says that 90 deg. feed in is to be avoided as well. I've seen some recommend straight in-feed as giving just as good a result (with carbide inserts perhaps?). I actually cut internal threads as shown by Keith, but the next time I do cut them I will try the Williams recommendation and see how it works.
I guess if you think the tooling engineers at J.H. Williams had no clue how to cut threads after 30 years experience, you must be smarter than they were.
I was taught to always set your compound so that you are only cutting on the leading face of the thread doing the cutting. While I have to agree that with carbide tooling, it probably does not matter as much, I still think it is good practice. If you just cram the tool into straight on, you are actually cutting on both the front and back of the V, and it makes sense to me that you want to cut on the leading edge and not be dragging on the back.
Keith, I'll send you a copy of the Williams bulletin. The bulletin says that there is better chip formation following their suggestion. Like you, I was taught to swing the compound to the left when threading internally. I had to read it several times to make sure I correctly understood their recommendation.
The advantage to the Williams suggestion is that the compound is not likely to have interference with something like a casting that was being threaded.
It's really surprising to see that much deflection on the spring cut passes. I knew there was some, but I wouldn't have guessed that much.
Thanks for sharing.
I think his surprise may have been in seeing so much deflection on the tool post where if the indicator were on the boring bar the deflection would have been expected.
I found that interesting, but I was hoping you'd also show whether you need any special considerations when doing the left-hand thread.
I have a left hand thread video coming out soon.
tail stock drills always spin. Get a large drill sleeve and stick a bar into it.
on that first internal cut where he sets zero, cut to full thread depth and mark zero, then make a cut through hole at half depth come out and set to your zero or full depth and finish it.
Should be strong enough for a table!!
Says the man with 26000 lbs rated industrial chain slings in his bedroom!
Sorry Brian, but I really had to laugh at Shermigtan's response to your comment!
Great work Keith! Is it true that once a drill/drill chuck spins inside the morsetaper due to the force applied that you have to ream it by hand?
Don't hold your breath if you want to see good practice here
Don't know if you've noticed, but your dial indicator is getting a little sticky. At 17:49 you moved the compound and it came clear for a moment before clicking back against the compound. I'd guess it's probably not a huge problem at this point, but may be something to keep in mind, in case it starts getting worse.
Yes, and I am about to send that indictor off to get serviced.
Keith, a question...
Could backlash be a contributing factor to the "spring" in this particular setup?
The depth of cut is being set by retracting the compound and the thread face of the nut away from machine center is engaged.
Would it be stiffer to retract past the the set point then move forward to the desired position?
That way the push from the pressure is against the engaged face of the nut thread.
More likely the diameter and length of the threading bar.
Thanks ! I was just wondering if that would help.
8:20 That's what you get when you are predrilling. Never predrill if your machine has power to run the final size drill. Center drilling is ok.
No, never predrill if your machine has enough power. Using any size of predrill will just increase shatter and burn the corners of your drill. There is no point arguing, this is easy to try, first drill with a predrilled hole and then same without predrilling (or better in reverse order, so that you don't ruin your drill in first hole) and listen to the sound of drilling and inspect surface quality and condition of your drill. Adequate amount of cooling is of course important in both cases.
How does it hit the start of the thread on each pass or how does it actually work?
thread dial indicator?
I was concerned about the .0725 cut, at first I thought it should be 1/2 that when read on the dial. At least on my SB lathe dial cutting on the radius 10ths would actually move a dial indicator 5ths. I couldn't read the dial indicator in the video so depending on the lathe's dial either it went the full 72.5 or 1/2 that.
The full 0.0725". It seems like a lot, but if you do the math, that is the correct depth for Acme at 8 TPI. The outside diameter of the shaft is 1-1/8" and the root of the thread is 1". Take 1/8" (0.125") and divide in half (threads on both sides) and you get 0.0625". Add 0.010" for clearance, and you get 0.0725".
Missed the 1/2 math that you already took. Really figured you would not have made that, unless your lathe dial had a different calibration. I think most compound dials have have the 2:1 ratio, but maybe not all. :-)
As you were cutting the depth to a half thou, did you measure the hole size after drilling or just rely on the drill cutting on size?
The fact that he used a drill for final size means he did not bother to measure and close was good enough, not a normal or typical approach but apparently ok in this case.
@@TroubledTimes2024 good lord a three year old video, i cant remember the context , there have been so many since, but i guess my comment was about the apparent discontinuity between length and diameter tolerances. Agreed sometimes near enough is quite good enough.
Nice. Maybe what I am seeing is a camera trick, but it seemed that the thread dial was jumpy or sticking and not turning smooth. Is there a lot of backlash in that thread dial, or is it sticky? OR, is it just the video, my internet connection, etc... ? :-D.
The indicator is sticky. Time to send it out to get serviced.
Ah, I thought I was seeing things. I have a Logan that had a funky thread dial, the drive gear was mangled and didn't engage properly with the lead screw and it did the same thing. Replacement gear fixed it right up. Hope it is an easy fix for you.
Keith ,William is talking about the thread dial not the dial indicator. Looks like you might just be confused there.
Un saludo desde México
sergio diaz Y otro saludo a Ud. desde Arizona. Hay miles de fans de El Señor Rucker alrededor del mundo. :)
Well you made that look easy enough Keith. looks good
It's the left handed threads that are tricky. Running the lathe backwards can be confusing. You can't allow interruptions.
That's OK John, I'm sure he has it all under control, he's a crafty feller. I'm also glad it's him doing it and not me!!
John F, Standard way to cut a LH screw is to just run the leadscrew "backwards", not the lathe, and start from the inside and run outwards, not very confusing to my eyes. Much more confusing cutting a RH thread with the lathe running backwards, but once mastered it's much better way...
I actually find that left hand threads are easier to cut than right hand ones. Much less likely to crash your cut.....
THANK YOU...for sharing.
How did you set the feed rate to get the thread pitch?
Bill Moore - if your lathe has a quick change gearbox you set that up for your desired threads per inch. Without a quick change gearbox, you set up the proper change gears for your desired thread.
Speaking of the drill bit spinning, why do bits (all or most) have circular shanks? It seems like square or hexagonal or three-sided or anything except circular would solve this spinning problem, yes? I know this one was a taper, but why not just make it non-circular so it could not spin?
JL Software
Sort of a clutch effect to be weakest link if a little too aggressive, imo
Several larger bits I've seen do have three flats on them, just for this issue. It costs more I guess is why it's not more common.
It's a lot easier to manufacture a round shaft to run true than a hex shaft.
JL Software - just a guess, but I would bet that 1 inch drill that Keith was using was a taper shank drill. Probably dug in and slipped because it is sharp and copper, brass and bronze are grabby materials.
Ah. So if a taper fit slips and spins, does that destroy the taper so it won't fit after that?
Hello there KEITH
Nice train of thought to follow through on an intended project. Call it "Sequence of Ops" prior to .....
May U let us have that Engineers Web site details please. Can't access it. Might need that in the foreseeable future, IA
Thanks for showing and sharing
ATB]
aRM
I need to contact you . What is the best way to do so? I have tried to e mail you that's not working. Thanks Keith
If you use the email address that I show at the start of my videos when my name pops up on screen, you should be able to reach me. I get tons of emails on it every day so I know it works.....
I agree squaring off the lip is a good tip but the fundamental issue here is the overly large "pilot" hole. If the pilot hole diameter was close to the drill web thickness there would be little tendency to self drill. Step drilling in general is a poor strategy that is excusable on wimpy machines but pointless on such a robust machine as used here.
My other issue is rather than relying on the drill cutting an accurately centered diameter it would be much better to bore to the final minor diameter and certainly not reversing the blank between minor diameter cutting and threading.
Acme threads for this is bit of overkill.. but you know that. For his project a multiple start Unified National thread would be better and easier to make. A 16 tpi four start thread would do the trick (Lathe set for 4 tpi with 16 tpi profile).
Unless the dining room tabletop is 2" thick steel plate, I don't think it would too hard to push the table leaves apart.
You do know why you would use a multi-start thread, don't you? ..So you won't be turning a crank all day to get the leaves apart.
chris0tube True, but cranking that little gear in the center 4X per inch of separation (8TPI but on left and right hand threads like a turnbuckle) may get tiresome if he needs to open the table often. Maybe it’s electric so no biggie...?
My motto - if it is worth doing, it is worth overdoing! Seriously, the guy who I am doing this for wanted Acme threads so that is what he got. And at the end of the day, it will work just fine so I did not see any reason in changing his mind.
Another enjoyable video, however unless you mate is a couple of hundred years old he did not design mechanism
A diy capstan table? Not for beginners
I purchased a RH Acme tap to do a job once for something like those bronzes... much easier...
Easier, yes, but I hated to spend the money on both a right and left hand tap to be used one time. And I could knock them off on the lathe in much less time than it would take to ship the tools to me.
The video ended unexpectedly, usually Keith has a little outro talking about continuing the project. I assume he just filmed the whole thing and didn't film an interlude?
That would be correct. My original plan was to do both the internal and external threads in one video, but when I started editing, I realized it needed to be broken into two episodes. And due to time constraints, I did not have time to go back to the shop to shoot that interlude.... What can I say, my productions are not made in Hollywood.....
Your productions are better than anything in hollywood, I only mentioned because it wasn't like your normal video intro's and outro's. Always appreciate your videos!
I'd love to know what sort of table needs anything close to 1 1/8"-8 acme threaded rods for moving the leaves. Great video, but something tells me this is beyond overkill. And I say that as someone who generally over-builds his projects.
Does it "need" acme? Probably not, but he does want a course lead on it so that he is not having to crank the table all day long to get it to move. With the left and right hand threads at 8TPI, four revolutions of the screw will move the table 1". With this course thread, Acme kind of makes sense.
Well - you've needed to make bronze slip-bearings at first ;)
Nice job, but you are an illusion, you make it look so easy when it is more difficult than it looks.
Practice. With practice, it does become easy (at least somewhat so.....)
TH-cam thinks the sound of your lathe is [Music], and I would have to agree. :)
Perhaps I should copyright that "music" so that everybody else has to give me royalties for including their machine "music" in the background of their videos.....
I think you should, and call it "The Rucker Mix". :-)
Someone is likely to tell you what to do at 8:20 for "safety reasons."
I'd ignore them, they are probably brought up under a "padded room" culture.
The calculator is disgusting!
Jörg Frede it works
why?
Yes I know it is a workshop calculator. But it looks like a bird has shit on it.
But it works that's all that matter isn't it?
Yes it is as long as I do not have to tap on it myself. :-)