Is Taper Attachment worth it?

[thestelster]

A couple of notes.

-if you've incorporated a solid toolpost, there is no compound therefore you can't utilize it for tapers

-you can still use the tail stock offset method to do tapers but if you have a long taper with a great angle, you might not be able to offset the tail stock enough

-you might also need to do a taper with a part between centers

-when using the compound for doing tapers longer than and inch or two, the inconsistant turning of the handle or stoping can transmit ridges into the work surface. If you're using the two hand approach to turn the compound handle, you can't squirt cutting fluid. (Yes, you can use a cordless drill to give yourself power feed, but on mine, the speed was too fast even on low, and controlling the speed was almost useless.)

I've used my homemade TTA to:
- do rifle and shotgun barrels
- make the abour adapter for balancing grinding wheels
- made several wooden spindle wipers for MT3, MT4, NMTB #40
-some other little projects I can't remember at the moment

-most important of all...

-it's a great project
-it's really cool
-bragging rights

 

[PeterT]

Adding to above, taper turning between centers with offset TS method will only yield the target taper angle for that particular length of stock. Swap in a different length of stock (or more specifically different distance between countersink cone depths) results in a different taper angle. How much deviation is acceptable or not acceptable is up to you. And then when you are done, is the obligatory re-dialing TS back on center. Of course there are other methods like using a boring head type TS accessory which maintains TS centered position but allows you to dial offset in/out with the accessory (my project #187).

Yes, good point about solid tool post. Part of my thinking is to make it solid & stable & repeatable enough but still not too onerous to readily swap the compound back on if required.

taper attachment really boils down to how much you anticipate needing this feature. I wish I had it, but grass is always greener....

 

[Dabbler]

There is a inexpensive alternative to a TA - Get a larger caliber boring head, fitted to your tailstock taper. I use a 3/4" one. on the big lathe and a 1/2" one on the little lathe. The big lathe HAS a taper attachment. (!!) The 3/4" one has a 2" throw - which covers most all taper threads possible, including some of the ASME threads used in the oilpatch. A decent offshore BH is about 200$, as oppposed to 500$+ for a TA, and the tricky install.

I use this in preference to the TA on the big lathe, because the offset feed on the TA is far coarser than using a boring head. It is far easier to dial in using the BH. To do this accurately and repeatably, you need round head centres.

 

[PeterT]

Of course there are other methods like using a boring head type TS accessory

There's an echo in the room Haha.

I bought an MT3 shank for my sacrificial BH & played around with it. Another consideration is should be level (parallel to the bed) so that off center adjustment isn't also introducing an up/down pitch. I think the angle deviation is pretty small, but what I also noticed is I have a teeny but of axial slop in my TS quill due to the key way. I think if I lock it, it goes away. Anyways, interesting discussion - has anyone done this operation with other points or setup advise? I might actually take a crack at it on some non critical parts.

 

[Janger]

There is a inexpensive alternative to a TA - Get a larger caliber boring head, fitted to your tailstock taper. I use a 3/4" one. on the big lathe and a 1/2" one on the little lathe. The big lathe HAS a taper attachment. (!!) The 3/4" one has a 2" throw - which covers most all taper threads possible, including some of the ASME threads used in the oilpatch. A decent offshore BH is about 200$, as oppposed to 500$+ for a TA, and the tricky install.

I use this in preference to the TA on the big lathe, because the offset feed on the TA is far coarser than using a boring head. It is far easier to dial in using the BH. To do this accurately and repeatably, you need round head centres.

Ok I have no idea what you mean. How is a boring head on the tailstock used to make tapers?

 

[YYCHM]

Ok I have no idea what you mean. How is a boring head on the tailstock used to make tapers?

Taper tool for lathe from boring head

Turning tapers can be a pain without a taper attachment. Moving the tailstock means that you have to put it back. Using a boring head from the mill is another simple way of doing it. I will show that in detail later. You do need a couple of special things. 1. A Morse Taper shaft for your...

www.hobby-machinist.com

 

[Dabbler]

Ok I have no idea what you mean. How is a boring head on the tailstock used to make tapers?

It is used, as @PeterT says, such that dialing the boring head provides horizontal movement. so inserted int the tailstock, with a round(not conical) centre into a drilled centre hole you can get an offset off centre by dialing the boring head. I'll bring mine over next time and demonstrate, if you like...

 

[PeterT]

Exactly. And this is what I was referring to as needs to be level. Or more correctly, parallel to the cross bed plane across the ways.

 

[thestelster]

Exactly. And this is what I was referring to as needs to be level. Or more correctly, parallel to the cross bed plane across the ways.

And I would think that the greater the displacement from the lathe axis center, the less contact there is between the headstock and tailstock centers and the workpiece centers, and therefore perhaps a greater propensity to chatter.

 

[Dabbler]

And I would think that the greater the displacement from the lathe axis center, the less contact there is between the headstock and tailstock centers and the workpiece centers, and therefore perhaps a greater propensity to chatter.

Not really.

You have to use a ball centre. you only get ring contact, but it is pretty much the same no matter what angkle. The 60 degree hole in the work has to be deeper, the larger the angle off centre.

 

[Susquatch]

There is a inexpensive alternative to a TA - Get a larger caliber boring head, fitted to your tailstock taper. I use a 3/4" one. on the big lathe and a 1/2" one on the little lathe........

There's an echo in the room Haha.

I think the angle deviation is pretty small, but what I also noticed is I have a teeny but of axial slop in my TS quill due to the key way. I think if I lock it, it goes away.

Yes, that makes it go away, but I find that locking it also allows a bit of slop to grow in the centres. What is tight at the beginning is often a wee bit loose after some machining.

More on this below.

Anyways, interesting discussion - has anyone done this operation with other points or setup advise?

Yes, I am well aware of this alternative and used it several times. Mainly because I DO NOT LIKE futzing up my tailstock alignment. Perhaps that is because I am too anal about doing it perfectly.

To do this accurately and repeatably, you need round head centres.

This is a wonderful comment.... And it may explain a lot of things I've wondered about.....

For example, I have always wondered about the problems that might arise using regular centers when using offsets. In my mind, I just couldn't see how the two non-concentric cones at each end could achieve their goal. I've always suspected that they simply didn't and that's why things often loosen up (see above).

I think that a Ball Center might be a better solution. Although U-Joints might be better still. The difference being friction.

I would also imagine that small is prolly better than big along with a high quality grease.

Ball centers used with a home made version of something like this might be better than a boring head.

And of course as I commented on another thread already, the MTaper definitely needs a tang for this job or @PeterT s concerns get magnified.

 

[Susquatch]

I see lots of you are discussing these very points. All good.

 

[Susquatch]

BTW, I just picked the Assorts version in the photo above. But I'm totally against even considering the Assorts brand. I have ZERO confidence in anything from India and from Assorts in particular. Bad experiences so far.

Hence my reason for suggesting something purpose made instead.

 

[thestelster]

Not really.

You have to use a ball centre. you only get ring contact, but it is pretty much the same no matter what angkle. The 60 degree hole in the work has to be deeper, the larger the angle off centre.

What?!! Ball center? I've never heard of that for a lathe, but makes perfect sense! In fact I use to use large bearing balls on my checkering cradle to allow for angular displacement on certain stocks. (The balls were too awkward to use, so now I use a carriage bolt).

 

[Dabbler]

I have both of mine stashed somewhere... safe. but go to 1:25 of this video to see one in person.

 

[Susquatch]

I have both of mine stashed somewhere... safe. but go to 1:25 of this video to see one in person.

That's hilarious! Gotta love the other language (whatever it is) interspersed with English names for the tools!

PS - THANK YOU for the time marker.

I had never imagined that commercial ball centers existed. Thanks for that too!

 

[kstrauss]

I've had a taper attachment for my Myford S7b for perhaps 20 years and have used it only a couple of times. For cutting tapered NPT threads or something with a Morse taper it is useful but a pain to setup. It sounds great to have all possible accessories for your lathe but unless your work is greatly different from my projects a taper attachment is probably not a a good investment.

 

[PeterT]

We have discussed this before. There is a specific profile center drill preferred for off center turning. I always assumed they were ellipsoid profile but maybe its radiused type-R? The point is once you offset a cone (tip) within a cone (center drill hole) it can no longer make nested surface contact, its partial tangent contact more like a point. A curved center drill has more like line contact, not perfect but better. That is not to say that ball end will not work the same way on standard 60-deg hole, it will. There was a good writeup on this somewhere related to balls & minimum submergence depth & size of ball per diameter...where I thought the conclusion was a different included angle like 82 or 90 or... was better than standard 60?

Counterbores and Countersinksll of Your Drill Options - Link Industries

LINK offers many different center drill options for all your drilling needs.

linkcuttingtools.com

 

[ducdon]

Lots of discussion about taper attachments has prompted me to think seriously about getting one.

My lathe came without one but it is still available as an accessory. It's the kind that bolts to the back of the cross slide and you remove the cross slide leade screw nut.

It's a lot of money. $550US plus shipping and taxes. Prolly a grand Canadian all in.

I replaced my old lathe with a brand new one 12 years ago now and never needed a taper attachment. Even now, the only job on the horizon is a balancing arbor for my surface grinder. WAAAAY cheaper to just buy the arbour! My guess is that I could also just make one using my compound.

I am only a few weeks from harvest and maybe a few months from completing my fall repairs. Then I get to play all winter in the shop. The main shop jobs are to convert my lathe to a 3-phase motor, and install a DRO. I think it would be rather foolish to ignore the possibility of installing the DRO Z Axis without considering the install of a taper attachment. So the time to decide once and for all is here.

Do I splurge on a taper attachment, or do I put the idea away forever?

If you have a taper attachment, what do you use it for? And could you have done that with a compound instead?

How would a taper attachment affect the price you would pay for a given lathe? (Thinking about my bride here.)

Have you ever wished you had one when you didn't?

Do you have one and ever wish you didn't?

How much of a chip trap are they?

How solid are they and do they ever have a negative affect on the rigidity, accuracy, and backlash of the cross slide?

Are there any questions I should have asked but didn't?

My Lathe came with a taper attachment. In the twenty years I've had it I have never used it. I cut short tapers with the compound. For long tapers I have seen setups that use a boring head mounted on a Morris taper to go in the lathe tailstock. Boring head allows incremental offsetting of the tailstock without having to move and reset it. Would be inexpensive to make using an import boring head.

 

[Susquatch]

We have discussed this before.

Unless my dementia has gotten worse, I think I missed that discussion. I'll have to see if I can find it. Can you help @YYCHM?

There is a specific profile center drill preferred for off center turning. I always assumed they were ellipsoid profile but maybe its radiused type-R?

My instincts tell me that a perfect sphere is ideal. I'll have to noodle this one tonight while I sleep.

The point is once you offset a cone (tip) within a cone (center drill hole) it can no longer make nested surface contact, its partial tangent contact more like a point. A curved center drill has more like line contact, not perfect but better.

Agree.

That is not to say that ball end will not work the same way on standard 60-deg hole, it will.

My guts are still telling me the ball and socket is perfect. But not a ball in a 60 degree hole. I think the perfect fit at any one time in a 60 degree hole on an angle is more like an ellipse - which will not work when it rotates.

Edit - didn't even get to sleep and realized this was wrong. A ball in a cone will never be an ellipse. It will always be a circle and will work just fine.

The only problem is wear. An oiled ball in socket will wear significantly less.

There was a good writeup on this somewhere related to balls & minimum submergence depth & size of ball per diameter...where I thought the conclusion was a different included angle like 82 or 90 or... was better than standard 60?

I don't think this reference applies to off axis turning.

But it is a great reference and I've bookmarked it!

What a great discussion this is becoming!