Hollow grinding a U2 - need maker

C

Cliff Stamp

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Anyone in Canada who can hollow grind a U2 from Fallkniven. I need the edge ~0.005", at ~0.010 at 1/8" back from the edge, and ~0.015 at ~1/4" back from the edge. Burning the edge at that thickness will be very trivial, so the maker needs to be very experienced with grinding very thin profiles.

-Cliff
 
Since you are calling out such tight specs, you should be aware that your dimensions are basically describing a flat grind not a hollow grind. Unless of course you can find a custom maker that has a 2346 foot diameter contact wheel. Then I guess you could theoretically holoow grind it. ;)
 
Can't be a "true" hollow grind then. The points of intersection you gave don't correlate to a 10 inch wheel diameter. The points you gave are basically linear
 
Laredo7mm said:
Can't be a "true" hollow grind then. The points of intersection you gave don't correlate to a 10 inch wheel diameter. The points you gave are basically linear
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As they are approximate, rounded off to the nearest 5. This is the profile that Alvin Johnson gave on one of his working knives, he is the one who ground it on the wheel noted in the above, he posts on rec.knives and has described his hollow grinding method in the past.

That knife was I think half an inch wide and 1/16" of an inch thick. I rounded the spec as they would be easier to remember and they are just rough benchmarks only, that is why the ~ was with them.

Note even a change in 0.001 makes it look very nonlinear consider for example 0.006, 0.009, 0.0016. Now the change in the last 1/8" is more than double what was in the first.

In fact this is the parctical measuring limit of many calipers anyway.

-Cliff
 
Something I don't get here is why do you want to regrind an existing blade from a U2?
From what I've seen the U2 is a flat grind, 62 HRC, laminate blade of SGPS, with a thickness of 2.5mm (about .0984").
Why grind it?
 
howiesatwork said:
Something I don't get here is why do you want to regrind an existing blade from a U2?
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Because it is a nice folder but much thicker than optimal for plastic, ropes, cardboard, woods, foods, etc. , standard light utility. Plus if it was hollow ground out it would be easier to sharpen to more acute edge angles <10 degrees included.

-Cliff
 
Sean is right as those spec's go
and to do it close or ~ ..
to hollow that out on an already flat ground blade ,,,have fun :)
you'll never get what we call into the grove.. there won't be much of one to follow.
if done by hand I'd like to have it in hand to measure it.
 
Dan Gray said:
you'll never get what we call into the grove.. there won't be much of one to follow.
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Alvin does it all the time in grinding out stockman patterns and other folders, he never made mention of it being difficult, the opposite in fact actually. Then again he does use some really high tech grinding equipment so maybe that is it.

-Cliff
 
Yeah, no one here would ever be able to pull that off. :rolleyes:
How hollow can that possibly really be with those specifications? Plus, trying to grind that, on an already hardened and flat ground blade without overheating it would be really fun. Why don't you send the knife to Alvin if he's all set up to do this? :confused:
 
Cliff Stamp said:
Alvin does it all the time in grinding out stockman patterns and other folders, he never made mention of it being difficult, the opposite in fact actually. Then again he does use some really high tech grinding equipment so maybe that is it.

-Cliff
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high tech grinding equipment :) that would be the ticket.
and Alvin would be the one to do it for you right? :)
the difficult part is from an already flat grind.
 
That's AlvinXX in AZ you're referring to?
From reading his posts, he likes to use full hardness steels.
What high-tech grind equipment has mentioned?
I don't recall any, and I'm not all that impressed with his knives.
To each his own, though.
Good luck with the project.
 
I can visualize Cliffy's review now:

"Custom knifemaker Smith reground the the blade very thin. The knife is now basically worthless for any medium to heavy work. When I chopped concrete blocks the edge chipped badly. Chipping was never a problem before Smith did the work."

"When I hammered the knife into a log point first, placed a 36" pipe over the handle and jerked sideways, the blade snapped! I was surprised at the results. The blade was not prone to snapping before Smith did his work."
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Then the Stumpies jump in:

"Why would anyone buy a knife from Smith? His blades do not hold up. His knives are crap. So says Cliffy."
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Why would any knifemaker take the chance of subjecting themselves to this? :confused:
 
Just a note on the "hollow" grind.

I have a disk for my 9" disk sander that has a 1* beveled face. The blades I grind on it are technically hollow ground I suppose :). I think 1* over a 4.5" surface is the equivalent of a 1600" wheel. I highly doubt there would be any noticeable difference between a flat grind and an almost "hollow" grind ;).

But, what the hell do I know ;) :)?

Matt
 
Chuck Bybee said:
I can visualize Cliffy's review now:

Then the Stumpies jump in:

Why would any knifemaker take the chance of subjecting themselves to this? :confused:
Click to expand...

a visualized Quote. :confused: nope I'm not thouching that one..
 
Dan Gray said:
Alvin would be the one to do it for you right?
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He already has in 1095, O1 and M2, he just doesn't work in stainless usually.

He has in the past, he ground some ATS-34 blades out and had them compared to 1095, they fell way short.

He is just a hobby class maker, he doesn't actually take orders.

howiesatwork said:
What high-tech grind equipment has mentioned?
Click to expand...
A five gallon bucket and a washing machine motor.

-Cliff
 
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