Shear bit grind

[mf205i]

This one goes out to Docn8as. I wanted to thank you for the tip on the shear grind. I tried it in the past, but I didn’t have much success. This evening I was making a part out of some A36 and I tried it again with 20 degrees off of vertical. The finish looked like the part came off a grinder, an absolutely unbelievable finish for mild steel. In 40+ years of doing this I had never heard about this grind. It is so easy and the results are so good that I find it a puzzle that it is not widely used.
Thanks again, Mike

[Hal]

Mike
Do you have any picture of the grind or the link to the grind thread?


Hal

[Black_Moons]

one thing iv wondered is exactly what way do you feed a shear bit?

I mean, assumeing a bit that slants down from right to left, do you feed it towards the headstock?
(like this bit: http://www.gadgetbuilder.com/VerticalShearBit.jpg (taken from http://www.gadgetbuilder.com/VerticalShearBit.html )

Id assume so, but it kinda looks like it might work the other way too?

And as for center height, I assume just any height where the 'peak' of the works radius contacts the shear area? Does the shear bit have any problems with really big diamiters?

[Carld]

That is just a left turning tool upside down in the holder. Surely you have to run the spindle in reverse to cut with it like that.

Just how is this setup used? Is this thread intended to start another long debate?

[Bob Ford]

Carld,

The tool cuts on the face not the top edge. In practice set the top edge above the center of the work. Cuts from tail stock to headstock. It is only for light finish type cuts, .003 or less.

Bob

[Davidhcnc]

This is what he is talking about. Make one and try it.

[Dunc]

On Davidhcnc's photo, exactly where/what is the cutting point/tip?

[Spin Doctor]

Originally Posted by Dunc

On Davidhcnc's photo, exactly where/what is the cutting point/tip?

Its the edge between the angled face and the back clearance

[Davidhcnc]

.

[mf205i]

Originally Posted by Carld

. Is this thread intended to start another long debate?

The thread was intended to thank Docn8as.
Mike