Cutting Internal Threads on the Metal Lathe: Threading a Custom Nova Chuck Insert

Cutting some internal threads to make a custom sized 1-1/8" - 10 TPI adapter for a Nova SuperNova2 chuck. This is for a friend of mine who has a similar wood lathe made by the Crescent Machine Company back in the 1950's. For whatever reason, Crescent decided to use a very non-standard thread size for the spindles on their lathes and no company makes a standard adapter to fit it. But, Nova does have a blank adapter that you can buy and have machined to whatever size spindle you like. That is my job of the day - to take that blank and make this custom adapter.
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[@formerparatrooper]

I finished my Tool Maker journeyman apprenticeship back in 1966. I left the trade in 1970, but I have one story that will remain with me. A guy behind me on an engine lathe was chasing threads on a long screw for some machine and I heard him hollering so I turned around to see him hitting the tool post with a wrench. I heard him say, "Git back in the furrow!" Of course he engaged the lead on the wrong number on the lathe and the tool was eating off the threads he already had cut. The next thing I remember was him picking up his tools on his bench and going to the parking lot. As far as I know he never when back to that shop.

[@formerparatrooper]

@Paolo G That was for sure--I am a bit shocked that I remember that from about 54 years ago.

[@skyjac92]

Been watching your videos for years Keith, but don’t think I’ve ever commented before. Just a short comment to say that I enjoy the variety you offer, and appreciate the time and effort that goes into these. Thank you sir.

[@DavidR8]

Fascinating to watch the dial indicator move as the cut progresses.

[@PhilG999]

Years ago I had a temp job at a plastic vacuum forming company. One day I hear cussing from the production area. Seems somebody had broken a similar insert on a fixture. I walk over and look at the part and then look in the scrap bin for a piece of steel (other insert was Aluminum). Guy says: "Damn. Now we have to have a machine shop make another part!" I say: "Why? You have a lathe and vertical mill right there" (covered in dust). He says: "Nobody here knows how to use those." I grin and say: "Beg to differ with ya on that one!" Knocked the part out in a few minutes...

[@spaert]

That's great! Love those moments.....very satisfying.

[@PhilG999]

@@spaert Yep! Was strange having a bunch of guys watching me do a relatively simple lathe job...

[@kerrywil1]

I applied for a job in the inter view the owner wanted me to tell him ALL jobs I have worked including cutting grass as a kid. I got the job. After a while I asked why all the question about jobs not revenant to the job. He said he wanted people who had a broad depth of skill and experience. I was applying as a financial analyst. Over the years I used all the information gained to help me ask question when evaluating a customers financial situation.

[@stanleybell2672]

It's awesome to watch my part being produced, ready to get the big Crescent L24 lathe turning again. Thanks again buddy!!

[@andreturnbull1259]

Fixing the bad cut made by the 1 inch drill is a very useful tip. Thanks for all your videos, very enjoyable and educational.

[@edbilek8033]

Being new to metal lathes (previously wood turning), THANK YOU for not time speeding your videos! It is very helpful to see and hear how metal work should look and sound.

[@ron827]

A true machinist's motto, "No problem, I have a machine shop, we can fix that." 10 tpi was during the transition between SAE and metric threads and was known as the "The Confusional Period".

[@jimhumphrey]

I couldn't help noticing the sly grin when you said " No problem I gotta machine shop". But good job sir! I have the same Nova chuck but fortunately I could buy the correct adaptor for my lathe.

[@calevel]

Among all the inside threads tutorials videos this is one of my favorite where a lot of information is explained for those like myself taking the first steps into the machining world. Keith is one of a few outstanding Utube guys that can get the skills well executed and passed on to the apprentice eager to learn. Thumbs way up!!

[@adamengland2519]

Always an education and impeccable timing as I need to cut an M13 X 1.0mm internal coming up. Thank you.

[@ad2309]

Hi Keith. Quite a few years ago (before youtube and the internet) I took a night course on using a lathe at a local "trade school". When it came time to cut some threads for the project, I was amazed to learn it was done as you described it this video... by moving a lever when a line on a moving dial lined up. I remember thinging no way was i going to be able to do that after just a few classes, but it worked. Thanks for sharing your projects via videos. Cheers

[@donaldnaymon3270]

Great work Keith. Very quickly made. Thank you for sharing.

[@SciPunk215]

Another happy customer !

[@elffirrdesign2063]

Well done! appreciate the consistent view of the dial indicator during the cuts and the sneak up to the final dimension.

[@maggs131]

One can only hope to one day be the kind of expert is his field that makes a lot of people glad they know you.

[@andyZ3500s]

Very true I was lucky and had some great mentors in my youth.

[@thijs199]

amazing video

[@whirlpool851]

Great work as always Keith!

[@nikond90ful1]

Thanks for the video Keith.

[@jukeman57]

Thanks Keith, much enjoy your videos.

[@markmonroe7330]

Wonderful video. Thanks so much for showing the details when cutting the threads.

[@garthbutton699]

This video is going to reinforce my memory as I have an up coming job much similar to this,thanks for the boost!

[@zeke1eod]

So peaceful to watch a true craftsman! Thanks for sharing, God bless

[@tpobrienjr]

Thanks for showing and explaining.

[@ssboot5663]

Nice work!

[@bcbloc02]

19:00 pretty wild seeing that tool post moving a couple of thou while in the cut.

[@clham612]

I noticed that, too. Is that normal? Do you do "spring cuts" until the springing disappears?

[@budehrmann5902]

Yes, spring passes until that goes away. But why is the whole tool post moving .005, that's .010 on the pitch diameter?

[@budehrmann5902]

Looks to me like the compound ways need tightening.

[@larrytomb3896]

Thought Keith took the sloop out all ready always more to do

[@mikecabe6127]

Enjoyed the lessons on threading!!

[@metalshopwithtroy5755]

Hi Keith, enjoyed your video and does have great content and yes threading is always good to revise on. Thank you for sharing keith.

[@johnwarkentinnikiskialaska8364]

You always do a excellent job 👍

[@elsdp-4560]

THANK YOU...for sharing. Very much enjoyed.

[@patrickreid2767]

So interesting to watch a machinist at work.

[@ruperthartop7202]

Nice work Keith

[@jdmccorful]

Enjoy your channel. Nice work!

[@cmonster6]

Great job,only thing I would have done differently was bore to final size before threading

[@brianstyrczula9466]

Nice work mr. Rucker

[@danbreyfogle8486]

I have one of those Craftsman lathes and had the same issue with their strange thread when I wanted to add a chuck. Fortunately I found one to fit.

[@dscdrkel5546]

KEITH** Enjoy your work on Leo's job.**looking fwd to see the next video on replacing the runner bush-ions for his threader mach.***DR KEL

[@keithdalton3004]

Good job their Keith. You know how it is when you're name is Keith Dalton WV4G. We Keith's stick up for one another.

[@millwrightrick1]

1 1/8"-10 thread is something I have seen before on a really old caster axle. A Scottish mechanic laughed when he saw it and said it was an obsolete standard called Whitworth Fine thread.

[@rennkafer13]

Looked it up, a BSF 1 1/8" thread would be 9TPI, not 10... the 1" BSF is 10TPI.

[@outsidescrewball]

enjoyed....

[@alanglen5902]

What I usually do when I want an internal thread and an external thread to run true and concentric is make up a dummy thread .in the chuck and then screw in the insert and then turn and bore and thread the insert. That ensures that the threads are all located on the lathe centre line

[@BedsitBob]

I'd have probably built a fixture, to hold it securely. A slug of metal, chucked up, then bored and threaded for the external thread of the adaptor. That would hold it secure, and guarantee absolute concentricity.

[@J0Gu7]

i blow those threads out anytime i go to fit, I've made the mistake of being "almost" there, only to take another pass and find myself with slop because the "almost" there was a chip keeping me from threading all the way through. :)

[@mausplan3890]

As an Apprentice in Australia in the 1960's working with British Standard Thread (BSF) and British Standard Whitworth (BSW) threads was normal fare as it was prior to the adoption of Unified and later on Metric threads.

[@dazaspc]

What a luxury cutting imperial threads in an imperial lathe. I'm jealous ... I did notice the clock on the turret moving around quite a bit. If it was for a metal lathe that would be a sign of run out?

[@lunkydog]

That was deflection from the cutting pressure.

[@dazaspc]

@@lunkydog Yes but it should have remained consistant

[@bret_Lambky]

Would there be a benefit to use a boring bar on your final diameter? It would help eliminate any walking of a bad grind drill. Great video, it’s been twenty plus years since I have single pointed threads. Keep the videos coming...👍👍

[@apollorobb]

When i do Threaded inserts and the like i take a piece of round and cut an internal thread in the round and use it as a fixture in the lathe chuck

[@seantap1415]

Machine it, mounted in the chuck its for.

[@renaissanceman5847]

agree... threading that adapter mounted in a 3 jaw and bumping it resulted in a bore that is not in the same axis as the threaded outer dimension... especially if he only indicated at one point point along the rotational axis... oh well. but since this a chuck used for wood, maybe that wasnt necessary?

[@medicmcauley6729]

Agree, there would be better holding against the chuck and the bore would be centered.

[@bigragu6828]

Isn’t the chuck dead ended, therefore would not be able to see when to stop, thusly rendering the chuck to the scrap pile?

[@seantap1415]

@@bigragu6828 Ive threaded many parts where i could not see what i was doing inside the bore.

[@bigragu6828]

sean tap not being a machinist, myself, I am in the auto repair industry. I enjoy watching this Keith and the other one, because of the mechanical and thought processes. But I would think the one inch drill, especially, would protrude out the back of the bore, before finishing its cut. Also the boring bar and bit would seem too close to the back to risk damaging the chuck or the tooling itself. Again, just my observations.

[@carbidegrd1]

I have a 1945 Machinists bible. There is a section on sharp V 60 degree threads, It shows proper thread form and various diameters but no rules in regard to pitch. I think it was an American thread, I have a few English books, never seen it there. I think you said "spring pass'? Up around Detroit we call it a free pass.

[@slypig24]

I was thinking about screwing solid adaptor into chuck, mound chuck & adaptor in a large 4 jaw, and cut thread with adaptor In Situ. It would keep adaptor true with chuck OD.

[@EdgePrecision]

That indicator sure moves a lot during the tread pass. Something isn't right with that machine. And its just between the saddle and the compound slide. It may be worth investigating what the problem is.

[@demonknight7965]

it's old and worn out. he knows its old and worn out. so he can compensate for it.

[@clham612]

I am surprised that you didn't make a mandrel to hold that adapter. Would certainly have been more secure and surely that would be important when having the threads exactly parallel with the center line was critical.

[@mark-]

😊👍

[@raymondengineering8951]

G’day

[@forrestsecord7743]

What type of threading insert do you prefer: partial profile or full profile?

[@Boultonful]

hi Keith, I saw your video , on the thread adaptor for a lathe, one thing I notest was that you did not cut a recess for the part of the lathe mandrel that dose not have any threads on it, I believe it is called the register. would be interested in you comments, all best keep up the good work, JB UK

[@masteruniverse3506]

The old Powermatic 90 lathes used the same thread

[@medicmcauley6729]

Would heat treating the part afterwards be of any benefit?

[@rmiller3423]

“Rinse and Repeat” was never necessary. Instead the recommendation was developed by the marketing department of a shampoo company and it resulted in much higher sales.

[@PeterWMeek]

Prell™ if I recall correctly.

[@scottr939]

Sorry, but his is mythical nonsense. I can definitely tell the difference when shampooing once versus twice. Basic chemistry principles, where the standard is to wash/rinse three times - each pass removes exponentially more debris - e.g. if the first pass removes 50% of the dirt because the solvent gets 'saturated' with debris, then the second pass removes 50% of the remaining 50%, etc.

[@cavemaneca]

@@scottr939 the question though is if the extra washes were ever necessary. It's well documented that shampoo that does not lather sold worse so they introduced lathering agents into the hair. But the lathering agent actually damages hair. Conditioner helps undo some of the damage, but ideally you'd want a shampoo that's both effective at removing dirt and grease but still leaves the hair healthy.

[@garyknight3019]

I am thinking that may have been some sort of standard chuck thread back in the day Fay &Egan used the same thread

[@garygenerous8982]

Keith, while you were doing the internal threads the micrometer you were using for thread depth was showing a various amount of deflection every time you started cutting the threads. I know you were talking about tool pressure in the video and I was wondering if this deflection was an accurate measure of the tool pressure or if it is too unreliable to be used that way?

[@edwardbarton1680]

How accurate do you need to be when engaging the feed? If you're slightly off, will it align into a groove, or will that pass be slightly off?

[@Paradix333]

About the dial indicator what happens if you engaged 1/16 or 1/8 in before or after the line.

[@J0Gu7]

At least on my lathe, you have some grace. There are positions between the numbers but as long as you engage after them, the paw will fall into gear.

[@ROTTK9]

I think it you could have made deeper cuts if you made a holder for the part to screw in, knowing it is a 1 off part the cheapest ( cost effective ) way was done.

[@paultavres9830]

I had a 6” craftsman lathe which is made by atlas The craftsman spindle is a 1” 10 thread Atlas is 1” 8 thread which chucks are easy to find But craftsman not so easy to find so I made a backing plate to fit mine Then one day while at a friends house I seen he had the same craftsman lathe But with a atlas chuck What I found was someone had cut 1” 10 threads right over the top of the 1” 8 threads The chuck would actually fit both spindles

[@RobertFay]

*Nice educational tutorial for me as a no-experience novice, Keith. | | | Am i correct; that machined-piece cooling caused for the test piece to still be tight after reaching the book-defined ID was reached? This required two "spring-pass" finishings after the piece had time to cool and contract back to room temp [or STP (standard temp and pressure) as a chemist would think of it]?*

[@MrPatdeeee]

Would not using a sleeve with a tight internal thread; where the adapter screws into the sleeve; make the chuck hold it better. Or would that be making things worse?

[@michaelpedersen1672]

Keith, what do with all of your chips and shavings from your machine shop. Often wondered this. Guys like you and Abom79 must generate quite a pile over time.

[@MrTech337]

After bringing the cutter out of the part does it have to be in the exact same spot before making the next cut. And how does the stop work on the cross slide

[@chrisarmstrong8198]

No, it doesn't have to be in the same spot for the next cut. The thread chasing dial (with the numbers on it) is attached to the carriage; so when the half nuts are engaged with the lead screw to take a cut, the dial stops rotating. If the half nuts are engaged at the required number on the dial (with the carriage anywhere along the lathe bed), then it will still be on that number when the carriage passes the spot where they were engaged on the previous cut. (See kzbin.info/www/bejne/Z2GulqemptZgm68 from 7:30 on for a good explanation.)

[@garym1550]

You must have had your welding googles on when you picked that first 3/4 drill. Of all the drills you have, you kept that one? You know what they say, people are funny!

[@yhnbgt365]

As I commented to Adam Booth yesterday, when holding a part for us to look at, please hold it still so we can see it clearly. It is hard to see a moving object.

[@LouAdzima]

Keith, what is a "spring Pass"? Great Video.

[@ericmcrae7758]

A spring pass is a final pass made with the same cutting dimension to clear out any burrs on the thread. It also allows for any deflection of the cutting bar.

[@stxrynn]

It's a pass where you don't make any adjustments to the depth of cut. Cutting pressure will push the thin boring bar away from the cut, and just repeating the cut without increasing the depth allows it to take a smaller cut with less flexing away from the cut. In essence, the springiness of the tool adjusts the depth of cut. It's usually whisker thin.

[@TheAmpair]

A short cut from winter to summer.

[@dhaynes4515]

Do any of the AH's ever tell you why they give you a thumbs down?

[@jcorbett63]

Keith, look at your video. Just as the bit starts cutting, it appears the bit rises ever so slightly like the tip of the bit is not on center. Like the bit tip is slightly low compared to the hole.

[@PeterWMeek]

It might be misalignment of the tailstock bore to the axis of the spindle (hard to fix) or it might be a slight bend in the drill bit itself (easy to fix by giving the drill bit a tap with a brass hammer).

[@sthenzel]

Why didn´t you screw the insert into your woodchuck and chuck that into the three-jaw?

[@talltimberswoodshop7552]

Hi Keith, Why no oil when drilling the 1/4 and larger bores? I know you don't use oil on cast iron, but that adapter was steel, right? I also wonder why you can't cut threads in both directions? It would save time.

[@allredtail]

How much wood would a Wood Chuck chuck , if a Wood Chuck could chuck wood?

[@tiredoldmechanic1791]

It's hard to believe that the company that makes the chuck and supplied the adapter couldn't put the proper thread in the adapter.

[@jonathansmith6390]

Keith, I like your videos. I used to sell for a shop that repaired paper mill equipment. They take me back. But now I have a question. What is the math for figuring the bore size? I cant seem to find it anywhere. I have poured thru the Machinery Handbook and found tables but want to know the math. I did find a video showing .6495 * 1/TPI = 100% thread depth. Multiply this by 2 and subtract from the 100% od of the male part. Where did the .6495 come from or how do you calculate the bore size for internal threads?

[@renaissanceman5847]

Why not install the threaded adapter into the chuck... indicate off the body of the chuck mounted on a large 4 jaw... cut the bore in the adapter and thread? IF the body of the chuck was questionable... mount a thick test bar onto the wood chuck(mid size range for the chuck)... then hold the test bar centered on a 4 jaw and finish the body of the wood chuck to get a good surface to register off of?

[@williamlott6631]

Keith, Do you have any idea how to cut both right & left hand threads to make a faceplate for a wood turning lathe? Delta has made faceplates like this so one can turn large bowls on the outboard spindle & use the same faceplate on the inboard spindle. Any information on how to cut these threads is greatly appreciated. Unable to find any info on the internet on how to accomplish this combination thread. Thank you, William

[@thomastutterrow3623]

I have a question. Might seem stupid but why not have a backing plat to also chuck up on in order to make heavier cuts. I understand the point of making sure not to mar up external threads but you could have done like I said previously or used brass or some softer material to take the blunt of that force. To be honest I’d rather use a plate than soft jaws. Any comments I’d really like to welcome

[@BuickDoc]

Keith, I have a question. I have watched years of machining videos and have never seen a machinist use a Follow Rest? Thanks, Fred.

[@boubaros]

kzbin.info/www/bejne/fHy3Z6Zmpp1osKs

[@mattradtke2190]

Can you do it from round stock? Wouldn't that be cheaper and a better instructional video? I want to make better inserts...the run-out afterwards? Looks true?

[@dcrahn]

What happened to finishing the repair on Leo's threading machine?

[@dolvaran]

Keith was waiting on a delivery as I recall.

[@dcrahn]

@jacktheripped He orders from McMaster Carr Atlanta store, then he could have that in 24 hrs. being he is in South Georgia.

[@aw738]

Could you have screwed the adapter in the chuck and then chucked it in the lathe? Use the chuck as a sort of mandrel?

[@garybeasley4885]

That would add another layer of inaccuracy. You dont know what kind of errors exist in the chuck.

[@sierraspecialtyauto7049]

I would do that if I had Stanley's chuck. No telling how close Keith's chuck and Stanley's chuck are for concentricity.

[@PeterWMeek]

@@garybeasley4885 - Actually, it removes one possible source of inaccuracy. If the engagement between the adapter and its intended chuck is slightly off, it will be off by that amount every time it is screwed into that chuck. Mounting the adapter to its chuck and then mounting the chuck to run true before machining the adapter will compensate for that inaccuracy. The ultimate objective is for the chuck to run true regardless of any errors that exist in the chuck. (If that adapter is in there turning somersaults, who cares, as long as the chuck runs true.)

[@sverreeriksen1982]

hi Keith, I see compond is 30 degree to the left when turning right hand threads. Will compond also be to the left when turning internal left hand threads?? mvh sverre eriksen

[@DRNewcomb]

Dumb question: How do you know when to use oil when cutting and how much to use?

[@ralfie8801]

Donald Newcomb You can't have too much oil when turning a part from steel. Some machines have a reservoir full of cutting fluid and a pump that runs a continuous flow of the fluid over the work for lubrication and cooling.

[@DRNewcomb]

@@ralfie8801 In this vid, Keith makes some cuts without oil and daubs some oil on other cuts. I've seen other videos where the operator ran a constant flow of oil over the entire process. I'm just ignorant enough to not know what factors control when you cut dry vs wet. I understand you're trying to keep the tool and work cool but don't understand the decision process.

[@ralfie8801]

Donald Newcomb There may be some editing in the vid that cut the oiling part out. Who knows? Some people go by the sound when the machine is cutting. There’s also oil on the cutting tool that flows towards the work, so it’s just up to the machinist. Also, depending on the material being machined, carbide tipped tools don’t require as much oil if any.

[@osgeld]

not to be "that guy" but it didn't help your BA drill bit's shank shoulder was sticking out so much, effectively reducing the diameter to the shank, while tooling the bidness end at 3x the size

[@kurtarmbrust]

Use an oddball thread size and you have a customer for life! Don't you just hate proprietary parts.

[@GUSMIX22]

Hi Keith: at the beginning you said "nothing in any standard size book for this thread" but then later on "according to the book" depth of thread is etc..." so whats up... ? Brian F.

[@richharr]

Probably the formula for thread depth in machininerys handbook. You can figure any thread depth as long as you plug in the numbers. Thats what I assumed he meant, I could be wrong though

[@victorreppeto7050]

I could be wrong. I don;t have any real experience. Did you see the tip of your second drill bit wander just a bit? If you start with a spot drill instead of a center drill when starting a hole you intend to drill trough you might not have this problem again.

[@smitty2868]

Nice job, thanks for the upload. Just a question though, wouldn't it be standard practice to blow out the debris left in the threaded hole before test fitting?

[@littleworkshopofhorrors2395]

Or de burr the inevitable ragged edge, unless Keith was using a full form 10tpi insert, which wasn't made clear.

[@spaert]

Probably, but what Keith did worked just fine. Didn't cause any problems. Hard to argue with success.

[@pzavada1]

seems like you'd be better off putting the insert in the chuck and clamping the chuck in the 4 jaw.

[@jamesgibbs9043]

Did he say "Nineteen Shvifties" ?

[@emilgabor88]

I shore don’t drill like that... small drill for pilot , and large . Step drilling is never a good idea...