Grinding problem

[Alarion]

I have a problem in doing a decent hollow grind on knife points.
I have no problem till the blade is straight, then, when it comes to following the point curve, it all gets messy?
How do you do it?
I've tried moving the blade to follow the point curve.
I've tried lifting the knife, but the grind always gets wobbly, or I manage to get a semi-hollow grind, but the to edge of the gorund section goes much higher than what I'd like, eating away most of the part of the blade sides I'd like to leave flat.
Any advice? How do you manage to produce a perfect grind on curved edges?

 

[Gene Martin]

As you follow the contour of the blade, imagine a centerline on your belt. The edge should be perpendicular, or at right angles, at that center line. So as you get to the blade belly or curve, bring the tang down so that the curve is always at right angles to the center.

If your groove is getting too low, push against the spine with your thumb. Not hard, just enough to raise the cenetr of your groove. That's assuming that you grind edge up. If the groove is getting too high on the blade, apply more pressure toward the cutting edge.

It's a lot easier to show you than tell you, and I haven't had my coffee yet so I may not have explained that well.

Gene

 

[Bruce Bump]

As you follow the contour of the blade, imagine a centerline on your belt. The edge should be perpendicular, or at right angles, at that center line. So as you get to the blade belly or curve, bring the tang down so that the curve is always at right angles to the center.

If your groove is getting too low, push against the spine with your thumb. Not hard, just enough to raise the cenetr of your groove. That's assuming that you grind edge up. If the groove is getting too high on the blade, apply more pressure toward the cutting edge.

It's a lot easier to show you than tell you, and I haven't had my coffee yet so I may not have explained that well.

Gene

It also helps to have a scribed line on the edge to go by. You will find that if you keep an eye on that line you can move the groove accordingly by putting pressure where its needed. Does this make sense? I had two cups already.

 

[kc custom]

Try grinding a small boot knife or dagger blade and to keep your centerline. Also presuming your flats are very close to being finished draw a line on the side of the blade.
Ken

 

[Alarion]

Thanks everybody. I'll try these tips.
:thumbup:

 

[Nathan the Machinist]

I'm a little slow replying to this one....

I think most people grind their profile first, then the bevels. I find it difficult to feel the center of a hollow grind at the tip because there is very little blade out there. Add to that the bend of the belly and the tip is pretty challenging (for me anyway). So I re-orded my operations to "do away with" the tip.

For this blade I did my grinding before I finished the rest of the profile. So, except for the little bit of finish grinding after HT, this knife (with a fairly pointy tip) required no real tip grinding

The blade on top is a "before". It becomes the blade on the bottom. The tip turned out *perfect*

 

[AcridSaint]

Neat solution to your problem Nathan.

 

[Bruce Bump]

I'm a little slow replying to this one....

I think most people grind their profile first, then the bevels. I find it difficult to feel the center of a hollow grind at the tip because there is very little blade out there. Add to that the bend of the belly and the tip is pretty challenging (for me anyway). So I re-orded my operations to "do away with" the tip.

For this blade I did my grinding before I finished the rest of the profile. So, except for the little bit of finish grinding after HT, this knife (with a fairly pointy tip) required no real tip grinding

The blade on top is a "before". It becomes the blade on the bottom. The tip turned out *perfect*

Good method. I never gave this any thought before. It looks like it would work great for knives that didnt have a strict profile.

 

[Alarion]

I'm a little slow replying to this one....

I think most people grind their profile first, then the bevels. I find it difficult to feel the center of a hollow grind at the tip because there is very little blade out there. Add to that the bend of the belly and the tip is pretty challenging (for me anyway). So I re-orded my operations to "do away with" the tip.

For this blade I did my grinding before I finished the rest of the profile. So, except for the little bit of finish grinding after HT, this knife (with a fairly pointy tip) required no real tip grinding

The blade on top is a "before". It becomes the blade on the bottom. The tip turned out *perfect*

Duh...
Nathan...
You DA MAN!
Simple, easy, clean...
Most of my forged knives come out with the "before" shape anyway, as trying to get a sharp tip by forging may lead to excessive decarburation or distortion (at least with my skill level).
Someone said that true genius is seeing simple things that nobody else noticed.
This is the first thing I'll try next time!
Thanks a LOT!

 

[Nathan the Machinist]

Duh...
Nathan...
You DA MAN!
Simple, easy, clean...
Most of my forged knives come out with the "before" shape anyway, as trying to get a sharp tip by forging may lead to excessive decarburation or distortion (at least with my skill level).
Someone said that true genius is seeing simple things that nobody else noticed.
This is the first thing I'll try next time!
Thanks a LOT!

Cool. Thanks.