Is Taper Attachment worth it?

[Susquatch]

Is there a way for you to decouple the cross-slide screw from its nut easily?

The parts that I made were either CR steel, HR steel, tool steel, aluminium, and angle iron.

Yes, the nut is anchored to the cross-slide via an accessible machine screw on top of the cross-slide. But the lathe was actually designed from the git-go for the taper attachment. All the anchors and screw holes are already there and there is simply a sheet metal cover where the cross slide extension for the taper attachment would normally go.

I had seen that you used what you had on-hand to make your taper attachment. I was more interested in what material you used to make your balancing arbor with. A taper attachment or custom tailstock offset system can wait. But I need to get on with balancing my grinding wheels.

 

[thestelster]

That isn't gunna work for the balance arbour which is 3 in 12 or about 14.477 degrees.

Please check again. I can't at the moment: the taper is 3" per foot, included angle, so app. 7degrees per side. So The 10 degree on the TTA is enough, no?

 

[Darren]

@Susquatch does your lathe have a t slotted cross slide?

 

[Susquatch]

Please check again. I can't at the moment: the taper is 3" per foot, included angle, so app. 7degrees per side. So The 10 degree on the TTA is enough, no?

Included angle??? Really?

I just checked and that detail didn't jump out at me. Every place I look just says 3 in 12. But yes, 7 seems more reasonable and would be within range for a taper attachment or a boring head offset. (not touching my tailstock - not ever). I'll confirm by measuring an adapter.

What steel did you use for the arbor?

 

[Susquatch]

@Susquatch does your lathe have a t slotted cross slide?

Sadly, no......

And no room to cut one either.

If I had a nickel for every time I've wished for that, I could buy a new lathe that had that.....

 

[thestelster]

Included angle??? Really?

I just checked and that detail didn't jump out at me. Every place I look just says 3 in 12. But yes, 7 seems more reasonable and would be within range for a taper attachment or a boring head offset. (not touching my tailstock - not ever). I'll confirm by measuring an adapter.

What steel did you use for the arbor?

It was Uddeholm Impax Supreme (I had a bunch of it already) Its basically P20 tool steel pre hardened to around 32Rc. And P20 is pretty close to 4140 in composition.

 

[Susquatch]

It was Uddeholm Impax Supreme (I had a bunch of it already) Its basically P20 tool steel pre hardened to around 32Rc. And P20 is pretty close to 4140 in composition.

I can prolly get 4140 pretty easy. 4140 machines pretty nicely if it hasn't been hardened. And I wouldn't harden it before or after anyways! If there were any questions about its history, I'd stick it in the fireplace for a day.

 

[Darren]

thats a taper attachment for the Emco v13 and Super 11 lathes. It attaches on the cross slide t slots and is therefore independent of the cross slide leadscrew. The cross slide just sets the depth of cut. Perhaps you could build something similar to replace the compound.

 

[thestelster]

I can prolly get 4140 pretty easy. 4140 machines pretty nicely if it hasn't been hardened. And I wouldn't harden it before or after anyways! If there were any questions about its history, I'd stick it in the fireplace for a day.

Actually, I find the prehardened stuff machines real nice with carbide. Almost mirror finishes with the right speed and feed.

But I think the balancing arbour can be almost any steel. It's not like it needs any strength. You'll only use it a couple of times throughout the life of a wheel.

 

[Susquatch]

thats a taper attachment for the Emco v13 and Super 11 lathes. It attaches on the cross slide t slots and is therefore independent of the cross slide leadscrew. The cross slide just sets the depth of cut. Perhaps you could build something similar to replace the compound.

Despite you posting before me, I didn't see it till just now. My wife has been complaining that I'm looking too much like Santa lately so I cut all the fur on my head (hair, beard, and eyebrows) right after that last posting.

I have not considered anything like that just yet. My focus has been on getting a factory taper attachment or at least duplicating the design.

But I confess that whenever I think about T-Slots, the first thing into my head is usually a slough of threaded holes like a fixture plate. I just have not warmed up to the idea of modifying my cross-slide that aggressively just yet.

But your taper attachment has many desirable aspects to it and I think implimenting that design would be the only non-original mod to the lathe itself. I think it's only 4 threaded holes on the top of the cross slide. Not such a huge leap of faith.

I assume the cross-slide leadscrew nut is released. How is the taper guide attached to the bed?

 

[Susquatch]

Actually, I find the prehardened stuff machines real nice with carbide. Almost mirror finishes with the right speed and feed.

But I think the balancing arbour can be almost any steel. It's not like it needs any strength. You'll only use it a couple of times throughout the life of a wheel.

The only problem with the pre-hardened is the need for carbide and its respective need for deeper cuts. There will be no finessing that cut a half tenth at a time. For a taper like that, I assume I'll have to fine-tune it to fit well enough for its role. So I assume it's time to get out the prussian blue and take teensy delicate cuts. No?

 

[Darren]

you don't have to mess with the crossfeed nut at all. The TA is pretty much independent. The crossfeed controls the depth of cut on the passes just as though you weren't turning a tapered part.

i built one here:

Emco V13 Taper attachment build

My V13 didn't come with a taper attachment, and they are impossible to find, so i'm building my own. Here's what they look like: I'm going to loosely base mine on the Emco design. I found an old brake lathe at the dump a while back, and took it home knowing that someday i'd do something with...

canadianhobbymetalworkers.com

its not quit done yet, but you'll probably get a better idea about how it works

 

[thestelster]

The only problem with the pre-hardened is the need for carbide and its respective need for deeper cuts. There will be no finessing that cut a half tenth at a time. For a taper like that, I assume I'll have to fine-tune it to fit well enough for its role. So I assume it's time to get out the prussian blue and take teensy delicate cuts. No?

No. You set up a sine bar to get the exact angle you want. Sure, use the Prussian blue afterwards to confirm and make you feel good.

And HSS cutters will easily cut 32 Rc.

 

[Susquatch]

No. You set up a sine bar to get the exact angle you want. Sure, use the Prussian blue afterwards to confirm and make you feel good.

I'm not really comfy with the sine bar approach on this task. I have no guide except an existing adapter (I'm not taking the spindle off my surface grinder). But I suppose I could measure it on the surface grinder...... Hmmm...... That is actually a good idea......

Otherwise, I have to setup and dial in an adapter and measure that. I won't use a sine bar, I'll just dial it in and cut to match.

I have zero faith in an exact 3/12 taper. Usually I find that tapers like that are never exactly what they say they are and Murphy always says mine will be something else.

And HSS cutters will easily cut 32 Rc.

I usually end up with chatter and a rough finish on hardened 4140 unless my cuts are 10 thou or more. I haven't had good success with fine cuts. Might be my grind.

 

[Susquatch]

but you'll probably get a better idea about how it works

I'm sorry Darren, I love the project and the work quality you are achieving. But I don't quite see how you can keep the cross-slide nut engaged with that design. It's prolly a small detail I missed after reading your original thread.

 

[Darren]

The taper attachment has its own cross slide that follows the angle bar. So the original cross slide only sets the infeed.

 

[Susquatch]

The taper attachment has its own cross slide that follows the angle bar. So the original cross slide only sets the infeed.

I missed that. The TA (taper attachment) has its own cross slide? How are the original and taper cross-slides linked to each other then?

 

[thestelster]

I'm not really comfy with the sine bar approach on this task. I have no guide except an existing adapter (I'm not taking the spindle off my surface grinder). But I suppose I could measure it on the surface grinder...... Hmmm...... That is actually a good idea......

Otherwise, I have to setup and dial in an adapter and measure that. I won't use a sine bar, I'll just dial it in and cut to match.

I have zero faith in an exact 3/12 taper. Usually I find that tapers like that are never exactly what they say they are and Murphy always says mine will be something else.



I usually end up with chatter and a rough finish on hardened 4140 unless my cuts are 10 thou or more. I haven't had good success with fine cuts. Might be my grind.

But you have a K.O. Lee surface grinder. Very reputable American company. If they specify a 3ipf taper for their spindle, you can be pretty sure that it is, unless it's scratched up or damaged. I would be more inclined to measure your adapter which is made off-shore.

Remember what you are making, a balancing arbour. Its just a device to hold your wheel vertically. It doesn't warrant half a tenth cuts. Wait til you start balancing and positioning those set screws on the balancing ring. It'll drive you mad!

 

[Darren]

I missed that. The TA (taper attachment) has its own cross slide? How are the original and taper cross-slides linked to each other then?

they are linked by the TA being mounted to the t slots on the cross slide. At the begining of the cut, the lathes original cross slide sets the DOC by moving the entire TA towards the work. The TA slide then follows the angle bar to produce the taper. The TA has its own slide and tool holder. The spindle is run in reverse.

 

[140mower]

Sadly, no......

And no room to cut one either.

If I had a nickel for every time I've wished for that, I could buy a new lathe that had that.....

You could make a nice little pallet with a decent hole pattern and mount it in place of the compound. Not quite a t-slotted cross slide, but it would still allow setups for line boring etc.