How to do a flat-grind on a reverse-curve

Joined
Apr 11, 2000
Messages
120
I would like to make a fairly radical looking fighter with a reverse curve blade. By that I mean slightly hooked downward like a Hawk's beak. Any thoughts or suggestions on the best way to go about doing this???

Thanks in advance!!!

Hugh
aka; 3/16th's

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Scraped, burnt, sliced, smashed. AHHHH, knifemaking!!!!
 
heh, actually I've been thinking about this one for awhile myself, got a couple hawkbill folder designs that're gonna require flat grinds
smile.gif

The two main ways I think would be easiest would probably be to use the edge of the platen (ie tilting the handle side of it off the side and just basically using the corner)
and/or just using the small contact wheel if you've got a square wheel or something similar, and just cleaning out the radius it leaves with files/paper. Somehow I get the feeling with either of those there's still going to be a fair bit of handwork to smooth out the grinds though
tongue.gif


Rich
 
Sumo you must have been reading my mind. That was the only way I thought of to do it as well. I was also thinking if you were to tilt your platen to the angle of the bevel and then rig up some kind of fence/clamping surface for the blade......

This would hopefully eliminate irregular grinds that occurr when I suffer uncontrollable muscle spasms while at the grinder (insert smiley here)

Or... you being a machinist, why don't you design, manufacture and market a jig for doing so. Try and keep it under 10 bucks (CDN) (another smiley insertion).

Later,

Hugh
aka; Totally Tactical

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President of Knifemakers Anonymous - "The sickness can be cured!" Call 1-800-cutfingers
 
Hawk Bills are best done on a hollow grinder
It can be flat ground but its lots of different twists..
Try a few blades first to get the hang of it.



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Web Site At www.darrelralph.com
 
If you check my website you will see several Hawkbills and recurves. I could not imagine flat grinding them! All my curved blades are hollow ground by hanging the belt off the side of a specially "rounded", soft contact wheel.
I have flat ground mild recurved blades on my disk grinder when I first started but they were only slightly recureved.
The idea of a rounded platen and tracking the belt over it may work. I'm not much into flat grinding so I'm not that sure!
Neil

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New Domain name, host, etc. Please bare with me!
Blackwood Knives http://blackwoodknives.com

[This message has been edited by Dr.Lathe (edited 06-15-2000).]
 
Okay, shop tip here for flat grinding recurves... buy flexible belts and instead of using a standard platten bty bolting a peice of inch and a half pipe where your platten usually sets... let the belt run along, NOT ACROSS, the pipe, that way you can flat grind a tighter curve than just using the edge of the platten and you can track your belt back and forth to keep from wearing out the outside 1/4 inch of your belts...

Its just a way that worked for me!

Alan...


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If a Man talks in the forest, and there is no Woman around to hear him, is he still wrong?
 
Alan,
How long it take you to figure that one out? It is so simple, it hurts!

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C Wilkins
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I don't care about no fightin' in Bosnia, I don't care about no trade with China! I just want to know when "they" are gonna do something about these God forsaken FIRE ANTS!!!
 
Well, I did a blade type like a combo of a MT kestrel back of the blade (warncliff style) and the edge grinds were kinda like the Vector. result, the Vectrel! Great for cutting open boxes, stryofaom, etc. I made the edge flat with no recurve (simple warncliff, no curve) to it to begin with and then flat ground that. Then I took a half round file and put the curve in it and worked it till it was smooth. Then I kinda swept the blade across the belt w/o platen in the direction of the curve. result, straight edge at the very tip for about 3/4 inch, then a curve all the way back to the finger notch. Grind is mostly flat and a little convex because I didn't use the platen. I like this convex type grind cuz my bevels aren't totally even yet! I also did a drop point tanto style knife. Somehow, I got a Yakote in one side of it. I think it was the slightly convex grind meeting the flat grind at the tip. I just gotta thin out the edge a little. I also started sharpening the blades with the belt sander and then finishing them with stone. Very nice edges! The recurve makes a great utility knife, especially the Vector style.
 
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