Help with Flat Grinding

Troop

Troop

Joined
Oct 26, 2006
Messages
2,898
Hey guys, I'm tired of "resting in my laurels" with regards to convex grinding on a slack belt, so I'm learning to flat grind.
I don't get it...how do you taper-in the curve of the belly, (near the point), so the edge will form at that location? With the slack belt, I can blend it in, so it's a nice, even transition.
But, with flat grinding, how in the heck do you make the transition from the belly to the straight part of the blade (and still have it be flat)?
I don't get it. Please help...I can't figure it out. I've attached a pic of what I have so far.
Thanks,
Mitch
 

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I "pull" the butt of the knife towards me (away from the grinder) as I get towards the tip to give it a taper. I kinda look like I'm doing some sort of weird twist as I work from ricasso to the tip of the knife.

Hope that makes sense.
 
Will Leavitt said:
I "pull" the butt of the knife towards me (away from the grinder) as I get towards the tip to give it a taper. I kinda look like I'm doing some sort of weird twist as I work from ricasso to the tip of the knife.

Hope that makes sense.
Click to expand...

So, you still have to pull the butt end of the blade towards you (away from the grinder), right? And it comes out flat? I don't see it.:grumpy: (But, I certainly believe you, Will)
Thanks,
Mitch
 
Ya like Will says pull the butt away as you move to the tip. Another way is, if you are doing a partial flat grind, is to rotate the butt down as you follow the curve of the blade.
This is where grinding free hand is better than using a work rest. think of it like sharpening and follow the blade edge from plunge to tip in one motion.

I hope this helps.
 
Oh its not all one plane. I think you are looking at the term flat grind to literally. You could have it completely flat on say a tonto with the tip on one plane and the edge on another but think of it as this and then blend those two planes.
 
If you look at the spine of a flat ground knife you should be able to see a mild curve in as it tapers to the tip.
 
Thanks. I think that I was looking at it as too "black & white". I know that there's got to be a taper towards the tip; it's just pulling it off that I can't get a grip on.
- Mitch
 
But, How do you "blend it in"? I mean, the taper still has to curve-in towards the tip, right? Then, do I still blend it with the flat platen, or use a slack belt?:confused:
- Mitch
 
I've nailed down the $64,000 question: How do I blend anything with the flat platen???
- Mitch
 
Hey Guys,...Someone please, please answer this one question for me.
When flat grinding, do you "blend" (see above posts) with the flat platen? Or do you do it with the slack belt? (It's still only one question.:))
Thanks again,
Mitch
 
Yes you do it on the platen.keep the blade moving and pull handle or tang toward your body while pressing blade against platen.give it a whirl..,you'll catch on pretty quick.
 
if done right you dont need to blend. i just shot the vid watch and you will see. dont use the slack belt. i will upload the vid right now. this is how i do it so others might have another way.
 
balibalistic said:
Yes you do it on the platen.keep the blade moving and pull handle or tang toward your body while pressing blade against platen.give it a whirl..,you'll catch on pretty quick.
Click to expand...

I've ruined a bunch of blades so far. I guess "pretty quick" ain't working for me.:o
Thanks for your reply. I thought I was going to get a break, and have somebody say, "Hey...you do it with a slack belt!" :D
- Mitch
 
I'll try this.
When you convex or hollow grind a blade, you taper tang to tip by very slightly pulling the tang toward you and applying a little more push on the tip as you grind from tang to tip.
When you flat grind a blade, you are still tapering from tang to tip by pulling the tang ever so slighhtly toward you as you go from tang to tip. The blade is on a straight line from top of the blade to where the edge will be sharpened all along the blade.
It is not on a straight line (ever so slightly) from tang to tip as you are tapering it there...
all with the flat platen.
Then since you are in fact tapering from tang to tip, and still want the blade to appear completely flat, checking it each time you pull it across the platen is very important.. As is so true with most all operations in knifemaking, practice and experience help a bunch...growing your feel of how to apply pull to the tang and push on the tip and still checking the appearance each time you work on the fron to tang taper is always gonna be a real good idea.
If this helps, Good.....do I get the $64,000.00? Just kidding.
If I didn't, sorry, at least I tried....
If you could get together with someone in your area for even a short time, it would be alot easier to show than trying to tell it.
One more thing, the feel of the steel as you grind it, to me, is almost as important as seeing it.
I know some makers wear gloves when grinding, that is fine. I don't, but you learn to dip the blade often.
 
John R. Fraps said:
I'll try this.
When you convex or hollow grind a blade, you taper tang to tip by very slightly pulling the tang toward you and applying a little more push on the tip as you grind from tang to tip.
When you flat grind a blade, you are still tapering from tang to tip by pulling the tang ever so slighhtly toward you as you go from tang to tip. The blade is on a straight line from top of the blade to where the edge will be sharpened all along the blade.
It is not on a straight line (ever so slightly) from tang to tip as you are tapering it there...
all with the flat platen.
Then since you are in fact tapering from tang to tip, and still want the blade to appear completely flat, checking it each time you pull it across the platen is very important.. As is so true with most all operations in knifemaking, practice and experience help a bunch...growing your feel of how to apply pull to the tang and push on the tip and still checking the appearance each time you work on the fron to tang taper is always gonna be a real good idea.
If this helps, Good.....do I get the $64,000.00? Just kidding.
If I didn't, sorry, at least I tried....
If you could get together with someone in your area for even a short time, it would be alot easier to show than trying to tell it.
One more thing, the feel of the steel as you grind it, to me, is almost as important as seeing it.
I know some makers wear gloves when grinding, that is fine. I don't, but you learn to dip the blade often.
Click to expand...

John, Do you, personally, flat grind with the edge up, or edge down?
My flat grinding comes out much better when I grind edge down.
Thanks,
Mitch
 
John R. Fraps said:
I'll try this.
When you convex or hollow grind a blade, you taper tang to tip by very slightly pulling the tang toward you and applying a little more push on the tip as you grind from tang to tip.
When you flat grind a blade, you are still tapering from tang to tip by pulling the tang ever so slighhtly toward you as you go from tang to tip. The blade is on a straight line from top of the blade to where the edge will be sharpened all along the blade.
It is not on a straight line (ever so slightly) from tang to tip as you are tapering it there...
all with the flat platen.
Then since you are in fact tapering from tang to tip, and still want the blade to appear completely flat, checking it each time you pull it across the platen is very important.. As is so true with most all operations in knifemaking, practice and experience help a bunch...growing your feel of how to apply pull to the tang and push on the tip and still checking the appearance each time you work on the fron to tang taper is always gonna be a real good idea.
If this helps, Good.....do I get the $64,000.00? Just kidding.
If I didn't, sorry, at least I tried....
If you could get together with someone in your area for even a short time, it would be alot easier to show than trying to tell it.
One more thing, the feel of the steel as you grind it, to me, is almost as important as seeing it.
I know some makers wear gloves when grinding, that is fine. I don't, but you learn to dip the blade often.
Click to expand...

John, Something you said just "clicked". You mean there is a slight taper all the way from the ricasso to the tip?! Not just at where the belly starts??? Holy Jesus! If that is true, then that would explain everything!
- Mitch
 
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