Which cutter to use on my Sherline Lathe

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chriscam
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Joined: Sun Feb 17, 2019 11:41 am

Which cutter to use on my Sherline Lathe

Post by chriscam »

Hi guys I am currently learning to use my Sherline lathe. My current intention is to remove metal (steel) along an
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item but not touch a corner. This is on a micro item but that is an issue I can handle as have microscope etc. The reason is the sholder is a part I wish to remove without touching (damaging)it and the way to do this is to remove metal to slide it off. Any suggestions as to tool

Regards
Chris
spro
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Re: Which cutter to use on my Sherline Lathe

Post by spro »

Thinbits by Kaiser, are smallest I know about. The tool holders are small too.
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Harold_V
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Re: Which cutter to use on my Sherline Lathe

Post by Harold_V »

??
It's not clear to me what you hope to accomplish. One does not generally remove a shoulder without it having been touched, so that's confusing. Can you provide a second drawing, showing what you hope to have the results look like?

The talk of "sliding off" material doesn't make much sense. Can you please be a little more descriptive?

It might help for you to detail the experience you have with a metal lathe. If you have never operated one, the answer you get will be more useful if the respondent knows that.

I'd personally be happy to help if I better understood your objective.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
chriscam
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Joined: Sun Feb 17, 2019 11:41 am

Re: Which cutter to use on my Sherline Lathe

Post by chriscam »

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Hi Harold, I have made a second drawing.

This is a balance staff a part of a watch or clock tiny being about 6mm long. The part I wish to release is the Green part or balance wheel this is held on to the staff by metal riveted over (the black). To safely remove the wheel the recommended procedure is to cut away the sear the wheel sits on which is the red colour. But you have to be careful not to damage the green part. So I need a cutter that will remove the red whilst not the green. If the green is cut into the poise of the balance wheel will be upset. I should add I have necessary collets and magnification but my machining skills such as which cutter are in need of improvement which is my current objective.
regards
Chris
RSG
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Re: Which cutter to use on my Sherline Lathe

Post by RSG »

I would just use a very sharp HSS cutter much like the gravers you use for watch making. While the part is static in the lathe touch up to it and zero your "Z" and "x" axis then as you are cutting, stop shy of the balance wheel by a few thousandths, same thing when you get close to the spindle. then you will likely be able to just pic the remaining part off with your nail or a bodkin.
Vision is not seeing things as they are, but as they will be.
Inspector
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Re: Which cutter to use on my Sherline Lathe

Post by Inspector »

You need to pick the brains of a watchmaker. Perhaps on a watchmaking forum if one exists. I know of one maker in Switzerland that might help you. His name is Martin Pauli and his business is Angular Momentum. https://www.angularmomentum.com/welcome.html He makes incredible Urushi fountain pens too.

Pete
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Harold_V
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Re: Which cutter to use on my Sherline Lathe

Post by Harold_V »

Ok, pretty simple. Given the project was mine to accomplish, I'd use a right hand turning tool. I suspect the lathe you have accommodates very small tools, perhaps ¼" or smaller. Easy enough to grind one, assuming you understand tool geometry.

For free cutting, I'd suggest creating positive rake via a small chip breaker. I'd also suggest you leave a sharp point, so you can remove the inside corner completely. When you get within a thou or so of both surfaces, the piece can most likely be removed without much effort. If you get it running dead true, you should be able to machine almost all of the part you'd like to remove, and not touch the rest.

I am not a clock maker, but I have experience in small work. Don't get in a hurry. Take small cuts repeatedly.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
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