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The Newbies Arena Are you new to knife making? Here is all the help you will need. |
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#1
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What Angle to shoot for.
I have an ajustable Jig and belt sander, i need to know what angle do i shoot for if i want a knife "Scary sharp"?
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#2
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I see from this post you haven't finished your grind yet. So disregard that portion. I can't answer on that, I grind by eye. I'd want the grind line about an inch from the edge, don't have a clue what angle that would be.
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#3
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__________________ God bless Texas! Now let's secede!! |
#4
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Awesome thank you Jack! |
#5
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__________________ A good friend told me one time about forging "What is there not to like, you get to break all the rules you were told as a kid, don't play with that it is sharp, don't play with fire, and don't beat on that" Wade Holloway See some of my work. |
#6
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The primary bevel angle would be a function of the blade thickness at the spine (or wherever the primary bevel starts), and the width of the blade. Therefore a narrow, thick blade (hunter, bowie) would necessarily have a steeper angle than a wide, thin blade like a chef's knife. The secondary bevel is usually 20 to 22 degrees, I think, at least that's what the professional cookbooks say to hold your knife to the sharpening steel or stone at...
__________________ Chris K. Two Mountains Forge Delta, BC, Canada www.twomountainsforge.com |
#7
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Both? I didnt know there was such a thing as a secondary bevel. I thought you set your angle and sharpened.
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#8
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The secondary bevel is the angle at which the edge of the blade is sharpened - that very small, narrow angle that makes the blade sharp. The primary bevel is the grind that covers most of the blade - what effectively turns a rectangular bar of steel into a V shaped blade .........
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#9
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Ok so no wonder it seems all i have been doing is putting on the Primary Bevel, so how exactly do i put the secondary bevel in with a jig and belt sander? |
#10
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That's one of the problems with using jigs - you just keep needing more and more of them. I know you said you had some arthritis but if you have the dexterity to build a jig you have the dexterity to grind freehand. Knife making is, for the most part, an old man's game and lots of us have arthritis and a few have much worse. You'll find a way.
That said, if you want to use a jig is exactly the same process as whatever jig you use for the primary bevel except with a different angle. You don't have to worry about the secondary bevel until you have a primary bevel and you have a way to go on that. As for the forge size, yep, sounds like you will eventually need a slightly larger forge. Right now though, there is no way I would be trying to make any blade more than 4" long at this point in your learning curve ... |
#11
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Think of it this way. If you have a typical flat ground knife, with the primary bevel going from the spine all the way to the edge, you will have a blade that will cut like a scalpel, but if it encounters resistance the edge is fragile and will likely fold or chip. There are two ways to deal with this, you can either make the primary bevel steeper (scandi grind), or you can add a secondary bevel.... or you could do both (saber grind). For a knifemaker, the primary bevel is ground before heat-treating, and maybe thinned a bit afterwards as the blade is polished. The secondary bevel is applied last, after everything else is finished, as it is what makes the knife sharp and we don't want to be bleeding all over the place... the cutting ability of the blade is dependent upon the angle of the secondary bevel, the amount of force needed to make the cut is also dependent upon the thickness of the edge and the acuteness of the primary bevel. I like a very thin edge, with a secondary bevel around 15-18 degrees per side, unless I know that the knife will be used roughly for chopping wood or bone, in those cases I'll leave the edge thicker with a less acute secondary bevel. __________________ A good friend told me one time about forging "What is there not to like, you get to break all the rules you were told as a kid, don't play with that it is sharp, don't play with fire, and don't beat on that" Wade Holloway See some of my work. |
#12
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#13
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QUOTE: So do i like set the jig for 25 degrees then switch it to like 12? Or the other way around?
Who knows? We didn't build the jig and we don't know the exact dimensions of the steel you're working with. But, as George explained, there are basically two steps: grind the primary bevel and later, after the knife is completely finished, do the secondary to create the edge followed by whatever method you choose (if any) to refine or possibly even polish the edge. If you want to use a jig you'll need to do the math to figure what angles are needed. That problem alone is a significant reason why 95% (probably conservative) give up on jigs after the first knife or two and learn to free hand ... |
Tags |
angle, arrow, belt, bevel, blade, bowie, chef's knife, degrees, edge, forge, grind, hunter, jig, knife, knife making, post, reference, sander, sharp, sharpening, steel, stone, thickness |
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