Author Topic: Turning a taper on thin bar  (Read 951 times)

Offline PaulR

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Turning a taper on thin bar
« on: July 04, 2025, 02:30:13 PM »
I'd like to put a short taper on the end of some thin (~3mm) rod. Is there any way some way to do this other than using a narrow tool with lots of overhang to avoid so much metal sticking out of the chuck? It works fine on this 1/4" hex but probably would go too well with this set up on a smaller diameter. The exact angle isn't critical but better accuracy and repeatability than grinding it by hand would be nice. I suppose some sort of form tool might do but I've never made one before.

Offline Charles Lamont

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Re: Turning a taper on thin bar
« Reply #1 on: July 04, 2025, 02:40:00 PM »
Can't you put the toolholder the other side of the post, and cut outwards from the centre?

Offline Jasonb

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Re: Turning a taper on thin bar
« Reply #2 on: July 04, 2025, 03:10:41 PM »
A lot will depend on how far back you can wind the cross slide to get the centre of the toolpost back as far as possible.

If it will go bar then having the tool holder on the opposite side of the post and using a right hand tool rather than the left hand that you show will be it with minimal work stick out.

You could also do it with a tool ground at 45deg then you can hold it at right angles to teh lathe axis and just feed in with the cross slide. Assuming it is 45deg you want.

A boring bar and the lathe running in reverse also works but have the tool cutting on the far side of the work.

Offline PaulR

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Re: Turning a taper on thin bar
« Reply #3 on: July 04, 2025, 03:26:26 PM »
Can't you put the toolholder the other side of the post, and cut outwards from the centre?
Not sure, I'll take a look! Thanks for the suggestion.

Offline PaulR

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Re: Turning a taper on thin bar
« Reply #4 on: July 04, 2025, 03:28:58 PM »
A lot will depend on how far back you can wind the cross slide to get the centre of the toolpost back as far as possible.

If it will go bar then having the tool holder on the opposite side of the post and using a right hand tool rather than the left hand that you show will be it with minimal work stick out.

You could also do it with a tool ground at 45deg then you can hold it at right angles to teh lathe axis and just feed in with the cross slide. Assuming it is 45deg you want.

A boring bar and the lathe running in reverse also works but have the tool cutting on the far side of the work.
I'll have a look at using a right-hand tool. I'd prefer to use the lathe protractor rather than grinding a tool so I know what the angle is and won't have to worry about keeping the angle when sharpening.

Offline PaulR

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Re: Turning a taper on thin bar
« Reply #5 on: July 04, 2025, 05:57:40 PM »
Happy to say that moving the a right-hand tool to the other side and cutting 'towards me' running the lathe in forward worked just fine.  :) :ThumbsUp:

Offline Roger B

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Re: Turning a taper on thin bar
« Reply #6 on: July 04, 2025, 06:46:44 PM »
Yup that's what I usually do:

Keep it near the chuck and keep it rigid.
Best regards

Roger

Offline PaulR

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Re: Turning a taper on thin bar
« Reply #7 on: July 04, 2025, 07:27:30 PM »
Yup that's what I usually do:

Keep it near the chuck and keep it rigid.
Thanks for the pics  :ThumbsUp:

 

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