Easy Method To Cut Tapered Threads On The Lathe
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- เผยแพร่เมื่อ 19 มิ.ย. 2024
- G'day everyone,
In this video I want to show you my method that I use to cut tapered threads. Tapered threads are somewhat unconventional things to cut, and the only time that I have seen them cut before, was on a big CNC lathe. My CNC lathe can not cut threads, so I will have to find a method using my manual mini lathe (Sieg C3 7x14). This method will involve using the offset tailstock method of turning between centers. By the end of this I hope to have made a new buffing wheel arbor/mandrel for the bench grinder. I hope you enjoy the video.
Tapered thread cutting tutorial
#machining #DIY #taperedthreads
Timestamps
0:00 - Intro
1:31 - Setting up the part in order to cut the tapered threads
5:32 - Cutting The tapered threads
6:50 - Testing the part
7:32 - Second attempt - วิทยาศาสตร์และเทคโนโลยี
To avoid chewing up your solid centres, make ball centres, which work great in the conical centre holes of your part.
I was going to mention the same thing. Definitely a better job all round with spherical centres.👍
I'd never heard of a ball centre before, great tip!
I think I have heard of someone doing that way back, but I'd have since forgotten about that. Sounds like a good idea though, especially for taper cutting. Cheers
You can also use a concave centre and a ball bearing, which gives you more size options.
@@howardosborne8647 certainly..good advice..point taken..!!
You turn the chuck by hand, in other videos as well, consider making yourself a cranking handle that fits into the bore of the head-stock on the back side, I find it gives me much more control when cutting threads especially when cutting to a shoulder. This project came out really nicely, you motivated me to have a go as well. keep up the interesting videos, thanks.Happy turing.
Very cool and easy way. I like that you went back on the lathe once you realized you could move the tailstock to the other side when editing.
I red some comments about a ball center. The idea is correct, a sphere gives you a full contact line. But the correct way is to use a center drill "type R" they have a radius instead of the 60° angle like a regular center drill "type A" has.
Mate that is a great suggestion. I don't do much off centre turning but those radius centre drills are something ill need to get my hands on. Cheers :)
Here is a video using a ball centre at on end and an R type centre on the other. - th-cam.com/video/vG7_RwGoy58/w-d-xo.html and another here showing tapered threading on a lathe male and female - th-cam.com/video/VV0z43RQrOM/w-d-xo.html
That was some really good problem solving you did there
I saw someone using a boring head in the tailstock to set the offset. That way you don't need to mess with the tailstock alignment.
that is a really good idea for light parts
Similar idea shown in this video: th-cam.com/video/028wW5axznE/w-d-xo.html
Good one! One thing - if your overal stock length between centers would be shorter - the taper would be steeper. Its all about trigonometry :)
Yes that definitely helped, now thabkfully its all set up to do it for a full taper on a larger part now that the tailstock can move in both directions. So I should be able to achieve 8 degrees with the full size stock, although I'm not sure if I'm game enough to push it that far.
Edited to make the comment make sense :)
Very interesting! Thanks for sharing. 👍
First time seeing how tapered threads are made. Thank you 🙂👍
Nice job - that came out well. I seem to remember also seeing someone using a boring head in the tailstock too - to provide an adjustable amount of offset, if you need more than you can get from just the tailstock. I have not tried it personally though, so take this with a grain of salt 👍
This video came in perfect time for a project I have thank you so much
I might try this technique for making one of those wood splitting cone bits.
Impressive! I never made tapered threads.
That was useful , wanted to try some BSPT threads for my irrigation work making better ring and tail components that hang on.
Nice work
Very interesting, not a lot of experience with a lathe, but I understand what your doing.
The offset formula is O = ((D-d)/(2*l))*L where D is the large diameter, d the small. L the overall length of the work and l the length of the taper section. I made an offset device that attaches to the tailstock from a Model Engineer design and it works well. They are on ebay too as you ae most probably aware. Saves having to realign the tailstock. Thanks for this, great work.
The sherline is awesome for tapers cos the whole headstock and motor can be spun - I've made a morse taper 0 for the tailstock this way, and apart from being slow it worked great. Still use that part in a drill chuck to this day.
If you use a 3 phase motor to drive that lathe, then you can control it with a VFD. Giving you infinitely adjustable speeds, while retaining full torque at all speeds. Also it makes it Super Easy to rig up an inductive sensor mounted to a mag base that you can use as a automatic carriage stop.....because if the main motor stops, the carriage stops :) Being a VFD you can set it up for instant stopping as opposed to coast to stop. VFD are very very cheap off ebay. Even good brand ones like Fuji or Teco are less than 200 dollars.
Vfd doesnt give full torque at low rpm
You got there in the end - but next project building a lathe taper turning tailstock attachment?
ทำตามให้ผลงานเยี่ยมดีครับ
Forgive me for not understanding, but when you adjusted the tailstock you altered the piece that is on the prism. In the picture from the tail end it looked as if the tailstock could be adjusted against you quite a lot? More familiar with bigger lathes so there is a possibility/probability that I just don't get it...
1.5mm pitch is close enough to 16TPI, so probably and imperial external thread. :)
Ah it certainly would be, let me check next time in in the workshop. Might have caught myself out there. Cheers
It's all very well and nice to do taper turning using the offset tailstock method, the bugbear is to get the tailstock back on true centre! It takes me bloody ages to get my Chinese 12x19 lathe back to turning true parallels again
Yeah for sure, I definitely need to amke up one of those offset centres, would make doing this much easier. Cheers
How? Cut bar. Measure taper, adjust tailstock with DTI the required amount? Am I missing something?
R threads (BSPT designation from last century) Rc for internal, the thread form is normal to the axis. This is the same as you said for NPT.
Would you be able to make a M14x1.25 tapered hex plug? It's for a 1960's Ducati single cylinder crankshaft. M14's with a 1.5 thread are widely available, but the 1.25 thread is NLA. I'm not a machinist and don't have access to a lathe. Any assistance would be appreciated. Thanks.
What out making an insert for yhe brass one and then drillimg and tapping for the threads you need? Could have saved some time.
When do you plan on upgrading to a bigger bench lathe?
Why should he?
For a shallow taper like this, you could probably get just as close with one indicator and a ruler as what you did with the compound+indicator. At 6 degrees, The Z movement only needs to be 1/10th as accurate as the indicator reading to have the same effect on the angle. And consider you could measure over a much greater distance, a ruler measurement, and two lines scribed on the part should suffice. There is still the issue of doing the trigonometry though :p
You needed an offset tail stock center. That way you leave the tailstock central and move the center.
That is excellent.
So, what next?
How about a tapered internal threading?
How about using a tapered tap for that? Or would that be too easy?
It would be quite difficult using this method, because the tailstock support is where you would want to be internal threading.. Some of the smaller lathes like the Sherline have an adjustable head, which allows you to swivel the headstock to point forwards or backwards. This could be used to thread an internal taper, I think.
@@_Jester_tapered tap is limited to a small gradient taper = and < crest/length plus a steep spade tip. Gradient higher than that we risk full engagement where all crest bite into the cylinder at once, ending in a jammed and broken tool or broken chuck jaw if we determined to fight with the jam. The alternative for you may be CNC.
@@CraigsWorkshopoffset steady rest
@@EitriBrokkr good thinking 👍 but you would also need a very strange workpiece connection at the headstock end. Something like a car CV joint.
BUT THIS IS A NECESSARY THING AND EVERYONE SHOULD HAVE IT AT HOME
Making a taper turning attachment would be a nice project.
I noticed that when you were cutting the brass dead centre, your cutting tool was not at centre height, because the cone nearly went parallel near the tip. Good effort though, on that baby lathe. 👍👏👏🥃🥃 Cheers! From a crusty old tool maker. 😉
Shouldn't do it much harm for one cut :)
@@artisanmakes No it wouldn’t do any harm, but my point is, that if you want to cut an accurate cone, then the cutting tool edge must be at centre height, or the cone will have curved sides. I’ve made a simple gauge that sits on the cross slide and has a bolt sticking out if the base and the underside of the head is at centre height. It’s a simple matter to slide it over the cutting edge and set the tool height. 👍🏼😁
@@Afro408 I hear you, I set the compound using the scale on the cross slide, so I hardly was expecting a super accurate taper anyway. Oh well, sometimes its difficult to judge if the tool is perfect with a camera and lighting rig in the way :) Cheers
@@artisanmakes 👍🏼😁keep up the good work.
It would be easy to make a usable taper turning attachment for the mini lathe.
A linear bearing and rail long enough to use.
Make a clamp for both ends of the rail that will also clamp to the bed with adjustment and pivot in them.
Then disconnect your cross slide nut and secure it to the bearing on the rail. Adjustable clamp for maximum diameter flexibility
Adjust rail to suit taper required using bed as zero.
Turn around compound slide for finite adjustments to diamater
It will power feed and screw cut as required.
You must be new to this channel, it's not about how quickly and easily you can do things because he's still cutting with a hacksaw, when your paid by the hour it's about how looong you can milk the job. Anyone can grab a cheap porta ban and cut metal faster but doing it by hand is so much more rewarding.
@@TheWyleECoyote I just thought it was a cool upgrade for his lathe and he does do stuff like that.
Can I press the thumbs up button for this one?
Call me novice, but what synchronizes the compound slide travel to spindle rotation?
There is a leadscrew which can be engaged and it is connected to the spindle
There's a clear difference between the tapers, seems like a factor of two got lost somewhere
He said that he wasn't ble to make more taper than three degrees though he wanted five or six.
Лайк. Центр со смещением сделай и не мучайся.
A method I use to cut tapers and taper threads does not involve altering the tailback.. Just set up work as normal..Make up a device that clamps to the lathe bed and allows a smooth bar such as a large piece of ground keysteel to be mounted parallel to centre height but then positioned at the correct angle. I will end up lying out between the toolpost and the cross slide hand wheel..Then mount a DTI off the toolpost or unused portion of compound slide. Make the stylus run down the outside face of the keysteel. Now set it up so finished size of taper reads zero. As the tool moves down the cut towards the chuck use the cross slide hand wheel and maintain zero..You can use this method to bore a tapered hole as well. careful consideration and care not to knock the setup gives very quick and reliable results..Maths with get you the correct angle if it matters. Or else don't move guide and use dti on one side for male taper and opposite side for bore. Well worth making a device because once you have used it you will use it as a method more times than you imagine. Like those transition tapers that don't really matter..works well to about 10 deg and doesn't require resetting tailstock alignment
Hello, can you make trapezoidal threads on a mini lathe?
Yes, you just need a ACME shape cutter
@@artisanmakes do you know what gears they need? and in what position
@@kostasathens6465 that would depend on the particular lathe as they are all different, your lathe should have a gear list for all threads.
@@kostasathens6465 That depends on the pitch of the thread and the supplied gears on your machine. Read the manual for the correct setup.
@@kostasathens6465 - The shape of thread is defined by the cutting tool. The pitch of the threads is defined by the gearing of the lead screw.
👍👍😎👍👍
when cutting 60 deg threads you set up the toolpost at 29 degrees . then you feed the bit in 29 deg.not 0 degree. that way the toolbit cuts mostly only on one side . it stops the tearing of the thread when you get deep.
Yeah but I don't use my compound when thread cutting because I loose too much rigidity with it on.
Should have used the 4 jwas to offset the part and get the 5 degree taper.
LOL - think about it. How would that work once the chuck rotated?
@@johncoops6897😂😂😂 You are right. So maybe to use a 4 jaw that stick on the tail stock and put the center in it.
@@ophirb25 - yes, that is a good idea and easy way to offset the dead center. There are other ways too but need to make a special "offset center".
👍🏼👍🏼👍🏼👍🏼👍🏼🍎😎
did you know is called national pipe thread rather than standard pipe thread because is not standard but improper unit
For offset tailstock turning using a centre you should use a form R centre drill and a standard centre.
Here is a tapered knuckle form thread without a form tool - th-cam.com/video/sGnSdQi-Nt4/w-d-xo.html
An easier way would be to drill an offset centre on your mill.
You can make an offset center holder for the tailstock. Get some ideas from the kit used in this video: th-cam.com/video/028wW5axznE/w-d-xo.html
Thnks for the suggestion, I had a few other people reccomend them. I haven't looked too much into them but I wonder how you get the offset tailstock level with the centreline of the lathe. If it isn't perfectly horizontal it would effect the cut no?
@@artisanmakes - you can ensure the centre offset is only in one plane using a device called a "spirit level".
@@johncoops6897 hehe fair enough
I think the bar was shorter that made the angle larger. 🏴🇬🇧
Yes, but now its all set up to do it for a full size one now that I got the tailstock set up for moving the other way
Using alu inserts for steel and steel inserts for alu, you are truly ungovernable
No lathe is perfect, you are always turning a taper... To some degree!
"Took it over to the lathe and made a slot"
AHHHHHHHG
Then it's back to the mill to turn the taper!
And then I can cut the internal threads on the band saw :)
@@artisanmakes You have a Band-saw??? Blasphemy! 🤣
@@artisanmakes lololol
The solution do this.... a new benchgrinder with 1/2" threads.
Can you pay your way put of a problem? Of course! Should you? Hmm...
Next time we watch him go to a tool store and buy the right tool instead of making it. Is that fun content? Probably not so much and not at all what this channel is about.
@@_Jester_ It was a joke, Al.
Im not a real machinist but I know my way around a lathe and milling and some things that he's doing are wrong am i the only one seeing this
That wobbly stuff you buy is junk. A bench grinder should have precision mandrels, thick flat washers, and cup washers with decent runout and precision hole size. You just can't find them anywhere and have to make them.