Folder lock angle grinding jigs? And clarification of angles associated with lock?

Brian Avila

Brian Avila

Joined
Jan 2, 2011
Messages
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I have been putting together plans and parts to make a liner lock folder. I have now come to figuring out how to get the 8 degree angle on the tang and then the 2-3 angle on the lock face. I have seen some WIP and some videos that show jigs and explain some things but it just makes me more confused.

I understand the 8 degrees on the face of the tang that meets the lock, it can be flat or you can use a 4" diameter wheel to cut it in. But I am missing how to get the 8 degrees transferred to the tang face.

I am also confused on the angle of the lock face. I have seen talk stating that the lockup should be near the bottom of the lock face and have open space at the top, but then I saw some videos talking about it being in the other direction across the width of the lock face.

I was hoping you guys could clarify for me and then maybe show me your jigs that help with getting those angles with and explanation associated with the picture?

I have a KMG and a tool rest so what would I have to make to get it done correctly and have good lock up?

I should add that I have read the Terzuola book about the tactical folding knife. From what he says is you have the 8 degree radius tang face and then the lock face is ground to match the tang face. From there he just buffs the top par of the lock so that the bottom part ( 0.09" - .125" ) makes contact with the tang face. If I did that It just leave me with trying to figure out how to make the 8 degree angles on the tang face and then matching it to the lock face?

-Brian-
 
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Okay, Brian, here is a "jig" system I use on every liner lock to do the tang angle at that 8 degrees with a a flat cut, using a platen and table. I place a 120 belt stiff belt on the grinder, measure 7/8" from the belt ( I use a piece of metal cut to use for size ) and lay a 1/8"X 1" piece of mild steel length wise on the table. I use two wraps of masking tape to hold this down, remove the measuring spacer, and do the cut to the depth I want, remembering to leave room for the washer width. The 120 grit grind is what I want for a finish, so no further belt change is necessary. Frank
 
I use an Empire protractor/angle finder ($5) and set the platen angle 8.5 degrees to the work rest. Maybe it's too simple but it works for me.

Mark
 
Frank, I don't follow how you get 8 degrees that way. From what I think you are saying you have a flat platen with a 1/8" x 1" piece of mild steel 7/8" away from the belt and then you cut? Wouldn't that just give you a square face if the table was perpendicular to the platen/belt?
 
Rest the blade on the spacer and you have a triangle w/ 7/8" base, 1/8" height. Inverse tangent yields an angle of 8.13 degrees
 
This is how I see what has been said: (the little shim is the hatched area that is 1/8" thick)

9CD966AA-BB36-4B99-A792-9F2B5ACF3966_zpsddccplv3.jpg


Even if you do that and have the shim 7/8" away and it is 1/8" high, if it is flat and you put it to a flat platen and the flat platen is perpendicular to the tool rest ( 90 degree angle) you can't get an 8 degree angle off of it if you do what it shows in the picture, you get a square edge if the ricasso/tang is flat and parallel.

I ask because that is what I take away from what Frank Niro is saying.
 
More than one way to skin a cat. Your drawing is correct for doing it Frank's way. You simply have to angle the leading edge of the tang down until it hits the work rest. Right under where the "N" is in your drawing would be the fulcrum.
 
Varga Knives said:
More than one way to skin a cat. Your drawing is correct for doing it Frank's way. You simply have to angle the leading edge of the tang down until it hits the work rest. Right under where the "N" is in your drawing would be the fulcrum.
Click to expand...

I understand that. But Frank didn't say that.
 
Sorry I can't send pictures. I sure enjoy the conversations that happen and sure I too learn from them. I also know my "apparent" attitude can seem rough and very short and in truth I've been told that if you can put up with that, I seem to mellow out. Remember, in the end it's what works best for you that will get the job done.
Now after that what ways do you people use to cut the leaf to length after separating it from the liner? I have a stand I made just happens out of a 1/4" piece of 1" bar stock about 1 1/2" long. It has a leg about 1/16" X 3/8" X 2 1/2" long hard soldered to the RIGHT corner, if you place this brass piece down in front of you the length pointing away from you, and at an approximate 90 degrees to the brass piece. I place the liner on this with the leaf to my right hand side and kind of at 90 degrees and clamp it. I can now go to the belt grinder where I have a 22 or 16 grit belt. When I place the brass base on the table I can get a very close angle to the line that was scribed for length. Yes, this is a very fine grinding job that I often do in several try steps that require the blade to be mounted washers and all. Don't hesitate to give a better method if you know one or to explain what I have written. This is another step that works right every time with the trial steps and the a fine belt. The hand filing just doesn't seem to work out as well for me. Yes this is for a right hand folder. Frank
 
Frank, I wouldn't worry about how your attitude comes off. The fact that you still want to help and that you try to help matters.

It is hard to get everything when typing it out and then communicating over the forum or email. I will continue to ask questions until I understand.
 
Brian, that certainly is the needed attitude in this knife making thing. Remember I said a phone call could maybe help out on a lot of stuff
Don't hesitate to use my email. I just lost one of my long distant very qualified straight knife makers . He completed his first liner lock and was pleased with the results and me having helped him. Frank
 
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