Thank you very much, Keith, for backing out and showing how you're manipulating the controls. It adds tremendous value to your videos. I'm sure that a large fraction of your audience is like me, and does not have the means to perform machining themselves, and watch your videos to live vicariously through you and to learn how it's done. Also, I think it's time you show some love to your cherished horizontal mill and at least give it some fresh paint.
What I appreciate about your channel is that you seem to know that many of us here are not machinists so when a term is used you explain it. I have heard "spring pass" by several machinists but had no idea what it meant. I knew the term was used near the end of the machining but not what it was. So I learned something new tonight as well as be entertained by someone that knows his machines and how to use them. Thank you Keith.
Always nice to see manual machining. The new crop of young CNC machinists(using the term loosely) should have to go through a manual machining apprenticeship before ever cutting a chip on a CNC! Always good to know the basics.
We had a design engineer replace an 8620 cold-headed part with 12L14 on a screw machine. The part should have only been loaded in compression so the change was so much of a no-brainer that it didn't even need testing (or so they thought!). It turned out that dynamic inertial loading put the part in tension and they broke in the field, requiring an expensive field campaign. That experience caused the banning of 12L14 throughout the company, regardless of usage. No, I was not the design engineer that caused the problem. I was the test engineer that had to find out why it failed. 50 years later, leaded steel still causes bad memories. For what Keith was doing, it's a perfect material, making the turner's life a lot easier without compromising the actual use.
The leaded steel is a major factor in making this kind of awkward thread cutting possible. If the specifier will permit then always choose a piece of free cutting leaded. It makes the job so much less difficult.
I see you did this one a couple years ago Keith and like so many others have commented on how well your videos are done and your explanations are very through. Looks like I will be attempting to cut a new lead screw for my Southbend 16" new to me lathe that we talked about last week.. Hope your doing better my friend! Razor..
Only 'issue' I have with this is I'd really like to know a bit more about the machines that these parts go in! So many interesting parts! Even a few photos of the install would be good.
Just whipped up that 2 TPI shaft there Kieth. Made it look so easy. How the heck did you feed in like that to start the cut ever pass? never seen that before. No relief area to start the next pass at depth. I still don't know how you find the time to work in that beautiful shop, volunteer at the museum, edit your many videos and work on that scientist job during the week?? Oh and all the meet and greets you go to. Busy man, I love it!
Not all machinists are comfortable feeding into a L/H thread without an undercut at the start. It’s far easier to pullout than feed in. If you need to cut a L/H without a undercut just invert the cutter ( adjust to centreline ) run in reverse but feed forward. This is actually a better approach to thin shafts, the cutting force pushes the shaft down instead of lifting it where the chatter will nominally occur . reverse turning on thin wall tubing that has substantial length will definitely benefit from this approach . Quite often cnc machines will use this approach to generate better work piece stability also. Not all machinists are aware of this approach or have forgotten about it’s benefits .💡
Nice one ,Keith. Them steep helix angle coarse threads can be awkward sods to cut if one isn't experienced. Also that is a crafty technique of feeding in some depth after the halfnuts are engaged. I got so busy talking about this video I almost forgot to subscribe. Its done now
Thank you for video. For fine tuning of any turned surface you can use shot peening via burnishing. It is obvious technique - just make rounded, lapped tool bit with needed shape (it is very similar to cutting tool bit), burnishing feed must be very slight (detail diamater depended), and rpm's must be higher. Such burnishing tool bit is not pulled by malleable steel during last, light passes like cutting tool bit. For rods, soft-soldered, hardened spheres (ball from different ball bearings/balls for hardness testing) are general, burnishing shapes. But this is just a theory, I didn't verify it in real world practice (especially during threading:).
Keith, Love you videos. I've seen everyone. Your through explanations are great. My only complaint is there aren't enough more often. Also I love you appreciation for history and your work to preserve the documentation.
I'm badly confused. At about 3:30, the included angle on the thread is 14-1/2 degrees so half of that is 12-1/4 degrees on the compound. My arithmetic says it is 7-1/4 degrees. What am I missing?
I think Keith meant to say 14.25 degree, not 12.25 degree. That would be 14.5 degree minus .5 degree. If you are cutting a 60 degree included angle thread, you set the compound to 29.5 degree.
Love watching you work Keith, but at 3:38 you confused the heck out of me. You said it was14 1/2 included angle and half of that is 12 1/4????? I am a novice and never cut acme threads so what am I missing?
I will be cutting an acme thread for a restoration, really like the acme fishtail gage, but do not understand the comment about 1/2 the included angle being 12 1/4 deg. Thanks for your great video!
Excellent, detailed video. I always enjoy hearing your thoughts about why you do something the way you do. I often try to outguess you before listening to what you have to say. I'm not always on the money! lol Thanks Keith!
When you started, the cuttings were only on one side of the rod, so, when you are done, your threads will be deeper on one side and shallower on the other, which will cause fitting problems.
It looks like you are using one of your Monarchs to cut the threads. Would you demonstrate how you setup the cross-slide locking screw to bring your feed back to "0" on each pass? I don't remember seeing the V-block vise jaws that you used on the horizontal mill before. Are they shop made? As always, another great video
Someday I've got to do some internal ACME thread for a leadscrew nut to repair an old 1920's era artisan lathe... it has a similar odd ball ACME thread 3/4"-2TPI-LH double start and seems like a stub as it's not full height. (Although, I don't have the ACME thread gauges to do all the checks you have done)
Awesome video, course threads for sure. I have limited experience with single point threading but what i do know is that its pretty time consuming and requires patience. Nice work!
Reminded me when I had to screwcut a 10 start Acme on a shaft. 1.660 lead, 0.1666 pitch Had to Really concentrate , and allow for the 6 tenths if a thou as I cut each thread.. Nightmare, but a really satisfying job when finished.
Fantastic work Keith. Any info the vise/jaw setup you used on the horizontal? I looked for a prior video that mentioned it, but couldn't find one. Thanks!
Keith, Good job, nice to see how it is done, last time I used a tool with a Acme thread was on an Oilfield Drilling Sub (Tubing Hanger) it was a little finer than that one though.
Hi Keith. Another good video and it makes me feel a lot more comfortable about acme threading. I have a question. You said that you set a stop for the carriage feed (y-axis). Is that an integral feature of your lathe or is it something you devised? Could you give a quick explanation or possibly show an amateur like me how it works? I am wondering if I could come up with something like that for my small lathe. Thanks.
You amaze watching you machining threads and I have a question. Can you machine threads with a separate and independent power feed on your leadscrew that in no way is connected to your lathe motor? Is there a formula or old timers trick ?
Excellent work, Keith. A very interesting video. I was particularly interested in how you fed it in at the start of the threads. i would imagine cutting a clearance groove would have weakened it too much. the start on the original piece looked quite abrupt. Do you think the original part may have been milled? Mart.
When I did lathe work as school, back in the 1970's, we always had a liquid pouring onto the work where you have a pot and brush. Is that just for filming or a prefered method?
I was going to mention this myself. Another way of achieving a thread with the same lead as this 2 TPI is to cut a 4 TPI with 2 starts. The method I use for this is mount the shaft to be cut in a drive dog and mount on a centre in the headstock. A drive plate or catchplate with 2 drive pins spaced 180 degrees apart is used to drive the dog. Workpiece and dog rotated 180 degrees to cut the second lead. This thread is classed as 4 TPI 2 start. One revolution will give the same linear lead as the 2 TPI. The depth of cut on the twin start is far less deep than the 2 TPI we've seen Keith cut here.
I learned tapping that way also. Always "Good Practice" in any material. Half turn, break the chip, another half turn. But I am an Engineer so we are kinda picky about things. Oh and "Wie Gehts!"
It's just a beefy tap. And also the stops and starts while turning the tap tends to break the chip in leaded steel. From my experience at least just keep going till the tap feels clogged then take it out completely and blow out the hole then go back in. I'm guessing that's what was cut out in the video.
How does 12.25 = 1/2 of 14.5 ? I don’t want to sound picky but I want to learn how to do acme threads correctly and this is a bit I have always wondered about.
Out of curiosity, why did you not just cut a recess where your threads started and then you could set your depth prior to engagement of your half nuts? It seems to me that it would be far easier and it would ensure all of your threads are the same depth.
Thank you very much, Keith, for backing out and showing how you're manipulating the controls. It adds tremendous value to your videos. I'm sure that a large fraction of your audience is like me, and does not have the means to perform machining themselves, and watch your videos to live vicariously through you and to learn how it's done.
Also, I think it's time you show some love to your cherished horizontal mill and at least give it some fresh paint.
I wish my dad was still alive. He'd have loved your channel.
Thank you for this video. I need to replace a cross slide lead screw on a lathe. This really helped. My wife won a USDA honors award when she worked.
What I appreciate about your channel is that you seem to know that many of us here are not machinists so when a term is used you explain it. I have heard "spring pass" by several machinists but had no idea what it meant. I knew the term was used near the end of the machining but not what it was. So I learned something new tonight as well as be entertained by someone that knows his machines and how to use them. Thank you Keith.
Always nice to see manual machining. The new crop of young CNC machinists(using the term loosely) should have to go through a manual machining apprenticeship before ever cutting a chip on a CNC! Always good to know the basics.
Your attention to restorative detail is what makes your videos so great to watch! Thanks Keith!
Beautiful job, great threading and machining the keyway on the horizontal was icing on the cake.
Next video: Inside tapered metric left-handed blind hole threads in Titanium (while blindfolded and one hand tied)
You forgot to add single point threading...
"Spring Pass"--Brilliant concept, thank you, I learned something !!
16:25 I literally clapped and said "bravo" at this point. Well done Keith, very nicely done.
I said, "and...that's how it's done!"
Got to love that Free machining steel. Haven't used that since High School.
We had a design engineer replace an 8620 cold-headed part with 12L14 on a screw machine. The part should have only been loaded in compression so the change was so much of a no-brainer that it didn't even need testing (or so they thought!). It turned out that dynamic inertial loading put the part in tension and they broke in the field, requiring an expensive field campaign. That experience caused the banning of 12L14 throughout the company, regardless of usage. No, I was not the design engineer that caused the problem. I was the test engineer that had to find out why it failed. 50 years later, leaded steel still causes bad memories.
For what Keith was doing, it's a perfect material, making the turner's life a lot easier without compromising the actual use.
The leaded steel is a major factor in making this kind of awkward thread cutting possible. If the specifier will permit then always choose a piece of free cutting leaded. It makes the job so much less difficult.
@@kensherwin4544 That isn't a surprise, it was also banned in the shop where I did my apprenticeship.
I see you did this one a couple years ago Keith and like so many others have commented on how well your videos are done and your explanations are very through.
Looks like I will be attempting to cut a new lead screw for my Southbend 16" new to me lathe that we talked about last week..
Hope your doing better my friend!
Razor..
you do a wonderful job of showing and explaining your process really enjoy watching your vids. keepem comin. thanks for the info.
Only 'issue' I have with this is I'd really like to know a bit more about the machines that these parts go in!
So many interesting parts! Even a few photos of the install would be good.
I'm sure Adam will post pics when he get is back on his instagram - blacksmithtools
@@CAPFlyer And / or he could be a member of OWWM.org?
Thanks for showing us every step in the process of making this piece. We all greatly appreciate you sharing your vast knowledge us Keith.
Just whipped up that 2 TPI shaft there Kieth. Made it look so easy.
How the heck did you feed in like that to start the cut ever pass? never seen that before. No relief area to start the next pass at depth.
I still don't know how you find the time to work in that beautiful shop, volunteer at the museum, edit your many videos and work on that scientist job during the week?? Oh and all the meet and greets you go to. Busy man, I love it!
Not all machinists are comfortable feeding into a L/H thread without an undercut at the start. It’s far easier to pullout than feed in. If you need to cut a L/H without a undercut just invert the cutter ( adjust to centreline ) run in reverse but feed forward. This is actually a better approach to thin shafts, the cutting force pushes the shaft down instead of lifting it where the chatter will nominally occur . reverse turning on thin wall tubing that has substantial length will definitely benefit from this approach
. Quite often cnc machines will use this approach to generate better work piece stability also. Not all machinists are aware of this approach or have forgotten about it’s benefits .💡
Great job Keith. You made that look easy. Thank you for sharing.
Cutting oil.. Your K&T will love you for it....Cheers; Mike in Louisiana
This is the first viewing of your model k lathe running.
I am happy to see it.
Thank you Keith!!
I missed the first step to establish OD. Then the nut not going in. But I’m the student and You are our teacher. Thank you.
Excellent, I don’t even have any machine tools but I love the process.
great video...discussion/demonstration/build....lots of lessons..thanks
Thanks for helping us, i am getting ready to start treading on my lathe and you been of great help
Great use of the 'stop' feature in the cross-feed.
65F in Keiths shop, perfect weather for doing some projects!
Keith, you make it look so easy. Great job!
You make things look so Easy! Thanks for another great video.
It was your rebuild of the plainer-matcher restore that Hooked me to your Channel...
Another great job......Thanks Keith!!
Thanks Keith
Nice one ,Keith. Them steep helix angle coarse threads can be awkward sods to cut if one isn't experienced. Also that is a crafty technique of feeding in some depth after the halfnuts are engaged. I got so busy talking about this video I almost forgot to subscribe. Its done now
Thanks Keith. I always enjoy your videos.
Saw your post on Instagram! That is a chunky thread. Glad you were able to copy it.
You make it look easy Keith.
Thank you for video.
For fine tuning of any turned surface you can use shot peening via burnishing. It is obvious technique - just make rounded, lapped tool bit with needed shape (it is very similar to cutting tool bit), burnishing feed must be very slight (detail diamater depended), and rpm's must be higher. Such burnishing tool bit is not pulled by malleable steel during last, light passes like cutting tool bit. For rods, soft-soldered, hardened spheres (ball from different ball bearings/balls for hardness testing) are general, burnishing shapes.
But this is just a theory, I didn't verify it in real world practice (especially during threading:).
Keith, Love you videos. I've seen everyone. Your through explanations are great. My only complaint is there aren't enough more often.
Also I love you appreciation for history and your work to preserve the documentation.
2:00 Leaded iron is handy to kill space vampires too.
Great fun. Thanks for sharing.
the huge ly coarse thread really makes clear the usefulness of a stop/start" gutter
THANK YOU...for sharing. Very nice. Watched and very much enjoyed.
You make it look easy, nice job
Thank you for posting another fine video.
I'm badly confused. At about 3:30, the included angle on the thread is 14-1/2 degrees so half of that is 12-1/4 degrees on the compound. My arithmetic says it is 7-1/4 degrees. What am I missing?
Acme included angle is 29 degrees, so half included is 14.5. .i am confused too.
@@littleworkshopofhorrors2395 That makes sense. The HALF angle is 14.5, making the 12.25 on the compound correct.
I think Keith meant to say 14.25 degree, not 12.25 degree. That would be 14.5 degree minus .5 degree. If you are cutting a 60 degree included angle thread, you set the compound to 29.5 degree.
Paul Topolski Nope, 14.5 minus 0.5 is 14.0. I’m confused too.
@@paultopolski1978 I had to watch it twice. I think you are write and it was just a slip of the tongue?
Keith I could hear the relief when the thread worked. Those operations, that are done rarely, still gets the sweat forming. 😁 Super nice work.
Keith, Nice work detail, it’s always interesting watching these types of threads being cut thanks for sharing.!.!.!.
Love watching you work Keith, but at 3:38 you confused the heck out of me. You said it was14 1/2 included angle and half of that is 12 1/4????? I am a novice and never cut acme threads so what am I missing?
Dave Calabretta confused the hell outa me too.
@@hodgepodgeenginerd1258 Same here.
I also agree that was confusing. Would like to know how those numbers were arrived at.
I will be cutting an acme thread for a restoration, really like the acme fishtail gage, but do not understand the comment about 1/2 the included angle being 12 1/4 deg. Thanks for your great video!
Good video,
I'm very surprised that such a course thread over that distance, didn't chatter.
Great job Keith. 🇬🇧
Well done!
Excellent, detailed video. I always enjoy hearing your thoughts about why you do something the way you do. I often try to outguess you before listening to what you have to say. I'm not always on the money! lol Thanks Keith!
Depth stop on the cross slide is nice. Wish mine had that..
When you started, the cuttings were only on one side of the rod, so, when you are done, your threads will be deeper on one side and shallower on the other, which will cause fitting problems.
The thread makes contact on the flanks. There is clearance between crest and root so the runout will only vary the clearance, not affect the fit.
Most Excellent Video. Thanks!
What a beast of a thread! Beautiful 😁. Pretty sure that would RIP the compound right off my little lathe 🤣. Great work👍😁👍.
It looks like you are using one of your Monarchs to cut the threads. Would you demonstrate how you setup the cross-slide locking screw to bring your feed back to "0" on each pass? I don't remember seeing the V-block vise jaws that you used on the horizontal mill before. Are they shop made? As always, another great video
Great Job!
Someday I've got to do some internal ACME thread for a leadscrew nut to repair an old 1920's era artisan lathe... it has a similar odd ball ACME thread 3/4"-2TPI-LH double start and seems like a stub as it's not full height. (Although, I don't have the ACME thread gauges to do all the checks you have done)
Thanks Keith always very interesting 👍🇦🇺
Came out nice!
Awesome video, course threads for sure. I have limited experience with single point threading but what i do know is that its pretty time consuming and requires patience. Nice work!
I love turning leaded material...12L14 preferably.
Love the channel! Can you share more info about the "stop" you mention? Maybe you already have?
Nice job as usual Keith
Reminded me when I had to screwcut a 10 start Acme on a shaft.
1.660 lead, 0.1666 pitch
Had to Really concentrate , and allow for the 6 tenths if a thou as I cut each thread..
Nightmare, but a really satisfying job when finished.
Fantastic work Keith. Any info the vise/jaw setup you used on the horizontal? I looked for a prior video that mentioned it, but couldn't find one. Thanks!
Keith! This is outstanding!! Thank you!!
Thank goodness for Leadloy. Any courser thread than that would be called an auger I guess.
Ah, now I get it, you're moving the compound in first. Gonna have to remember that trick, thanks!
That looks like fun, really impressed !
Keith,
Good job, nice to see how it is done, last time I used a tool with a Acme thread was on an Oilfield Drilling Sub (Tubing Hanger) it was a little finer than that one though.
nice cut
Boom! It fits.
Nice Job, ..... excellent video too.
Thanks for the detail on the horizontal versus vertical mill for cutting the keyway. Did you have to file the threads?
Thanks for the video, Keith. See you at the Bar-Z. Jon
Nice job
I guess cutting threads like that one is where the idea for the quick retract or retractable tool holder came from.
Thanks
Hi Keith. Another good video and it makes me feel a lot more comfortable about acme threading. I have a question. You said that you set a stop for the carriage feed (y-axis). Is that an integral feature of your lathe or is it something you devised? Could you give a quick explanation or possibly show an amateur like me how it works? I am wondering if I could come up with something like that for my small lathe. Thanks.
You amaze watching you machining threads and I have a question. Can you machine threads with a separate and independent power feed on your leadscrew that in no way is connected to your lathe motor? Is there a formula or old timers trick ?
Excellent work, Keith. A very interesting video. I was particularly interested in how you fed it in at the start of the threads. i would imagine cutting a clearance groove would have weakened it too much. the start on the original piece looked quite abrupt. Do you think the original part may have been milled? Mart.
When I did lathe work as school, back in the 1970's, we always had a liquid pouring onto the work where you have a pot and brush. Is that just for filming or a prefered method?
Hi Keith, Another great video. While turning threads do you feed in using the compound slide and what's your favorite cutting oil?
Wonder why you did not cut the outside diameter on the stock before cutting the thread?
Have you ever cut a multi lead thread on any parts? I have cut right and left threads but would like to see how a multi lead is cut.
I was going to mention this myself. Another way of achieving a thread with the same lead as this 2 TPI is to cut a 4 TPI with 2 starts. The method I use for this is mount the shaft to be cut in a drive dog and mount on a centre in the headstock. A drive plate or catchplate with 2 drive pins spaced 180 degrees apart is used to drive the dog. Workpiece and dog rotated 180 degrees to cut the second lead. This thread is classed as 4 TPI 2 start. One revolution will give the same linear lead as the 2 TPI. The depth of cut on the twin start is far less deep than the 2 TPI we've seen Keith cut here.
gd walters Mr. Pete has some very good videos of multi start threads.
@@howardosborne8647 that's interesting. I have worked on overhead cranes with load brakes. They had 4 lead thread were very quick acting.
You mention a stop on the carriage, is that something integrated into the lathe, or something you added/built?
Don't you have to turn the tap wrench backwards after some turns? I learned taping that way here in germany
I was taught the same here in the States to break the chip. Never worked with leaded steel, perhaps that's the difference?
@@sunny71169 So are you saying the lead makes it softer and threads go without binding and possibly snapping the tap?
I learned tapping that way also. Always "Good Practice" in any material. Half turn, break the chip, another half turn. But I am an Engineer so we are kinda picky about things. Oh and "Wie Gehts!"
Maybe that tap is big enough that it can resist torsional loads and the chip channels are large enough for evacuating the chips?
It's just a beefy tap. And also the stops and starts while turning the tap tends to break the chip in leaded steel. From my experience at least just keep going till the tap feels clogged then take it out completely and blow out the hole then go back in. I'm guessing that's what was cut out in the video.
Nice canon adjuster
Great job mate 👍🏻
How does 12.25 = 1/2 of 14.5 ?
I don’t want to sound picky but I want to learn how to do acme threads correctly and this is a bit I have always wondered about.
nice job!!!
I'm confused. 3:25 Half of 14 1/2 is 12 1/4?
William Garrett Me too. And I’ve been doing this stuff for 40 years.
you always do great work !
Very nice, hope it doesn't matter that much that the thread is a little off center, as you can clearly see on the first pass
Nope.
Good job!
Out of curiosity, why did you not just cut a recess where your threads started and then you could set your depth prior to engagement of your half nuts? It seems to me that it would be far easier and it would ensure all of your threads are the same depth.
New camera or new lighting? This video looks great.
Did you have the compound set at 7° or 14° . Sounded like a little chatter last couple of inches. Nice video!😁
Is there a reason for not truing up the stock before cutting threads?