Author Topic: Shear Tool for Lathe  (Read 354 times)

Uglydog

Shear Tool for Lathe
« on: August 03, 2018, 03:40:59 PM »
Below find a free link to a shear cutting tool for a lathe. It sounds like an alternative and nontraditional grind and application with specific benefits and limitations. I'm curious if anyone has used a shear cutter on a lathe and any input/perspective you might share.

http://www.homemadetools.net/forum/shear-tools-lathe-work-59276?utm_source=newsletter&utm_medium=email&utm_campaign=07-25-18#post88966


Thanks,
Daryl
MN

Carpenter84

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Re: Shear Tool for Lathe
« Reply #1 on: August 03, 2018, 04:33:25 PM »
I think I remember mr Pete doing and talking about a lathe shear tool. I also think I remember trying it. I didn't try for very long but I do remember mixed results. If I worked at it longer, I think I would have succeeded. The grind can be tricky  to nail. It does and should make an extremely smooth finish but very very light cuts.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

savarin

Re: Shear Tool for Lathe
« Reply #2 on: August 03, 2018, 08:11:07 PM »
I've ground and used one. No problems with the mild steel I used it on.
I dont remember the grind being particularly difficult.
I started with a new blank, radiused the edge, ground the angle so the now vertical radiused edge had a slight slant from vertical and went at it.
Very long wispy ultra fine swarf and the radiused edge allowed me to move it up or down to find the sweet spot.
Sorry but a bit of a time age so no pics.

ACHiPo

Re: Shear Tool for Lathe
« Reply #3 on: August 04, 2018, 03:57:16 AM »
Works great on soft metals.  I ground one once for turning copper.

chips and more

Re: Shear Tool for Lathe
« Reply #4 on: August 04, 2018, 06:49:07 AM »
Thanks for the tip! I have been using the standard profile on tool bits. I will keep this in mind.

groundhog

Re: Shear Tool for Lathe
« Reply #5 on: August 18, 2018, 07:32:20 PM »
I tried once awhile back using Mt Pete's as a guide. I don't even remember what I tried it on, but I remember that it didn't do so good. I didn't bother to try to figure out what I was doing wrong, I just abandoned it.

Carpenter84

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Re: Shear Tool for Lathe
« Reply #6 on: August 18, 2018, 07:57:12 PM »
Lol. I feel like one of us should give this another swing to provide some advise.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

Carpenter84

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Re: Shear Tool for Lathe
« Reply #7 on: August 18, 2018, 08:34:47 PM »
Nope. I'm out. Three swings and all I got was chatter.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

jocat54

Re: Shear Tool for Lathe
« Reply #8 on: August 18, 2018, 09:40:40 PM »
I have a couple that I made--they work okay with .002-.003 cut and get them long fine shavings 8)
I seldom use them, always forget about them until it's too late.
One nice thing about them is they don.t have to be on center so you can move the bit up/down as it gets dull.

higgite

Re: Shear Tool for Lathe
« Reply #9 on: August 18, 2018, 11:15:03 PM »
My story is pretty much the same as jocatís. Made one not long after I got my first mini lathe. It did a great job on the finish if you only took a 2 or 3 thou cut. The new shine wore off after a while and I havenít used it in I donít know how long. Itís stuffed in a drawer somewhere. I may dig it out now that Iíve been reminded of it and refresh my memory of why I quit using it.

Tom

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Re: Shear Tool for Lathe
« Reply #10 on: August 18, 2018, 11:21:51 PM »
If you do, post a picture of the grind. I must be doing it wrong.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

f350ca

Re: Shear Tool for Lathe
« Reply #11 on: August 18, 2018, 11:27:15 PM »
I use them from time to time. They give a good finish on gummy materials like structural steel, require very little force so work great if machining a long slander shaft, will remove a very light cut, so work when you need to take that last 1/2 thou for a fit. Even work on the shaper to give a great finish.

Greg

higgite

Re: Shear Tool for Lathe
« Reply #12 on: August 19, 2018, 09:08:49 AM »
Shawn,

I haven't looked for mine yet, but here's a better pic than I could take anyway. Thanks to gadgetbuilder.com.


Here's the link to the gadgetbuilder blurb about it.
http://www.gadgetbuilder.com/VerticalShearBit.html

It's actually a very easy grind as I recall. I'm sure the cutting edge on mine has a little more cant than the one in the pic, but it doesn't have to be exact anyway.

Tom

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Re: Shear Tool for Lathe
« Reply #13 on: August 19, 2018, 09:19:21 AM »
Ya, Iím in the ball park. I first tried a bit of a curved cutting edge, then ground it straight. All it did was make my lathe chatter like crazy. Mind, thereís been several topics recently of my lathes decent into a wollowed out pile of iron 😢

Iíll try it today on a piece of aluminum. I might be trying to cut something too hard. It was the taper test bar I still had chucked up.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.