Lockback Folder Tutorial

Sticks

Well-Known Member
Keith,

A handsome knife! When you file the rat tail on the bolster do you use a jig or file guide?

Jay
 

K R Johnson

Well-Known Member
Keith,

A handsome knife! When you file the rat tail on the bolster do you use a jig or file guide?

Jay
Thank you Jay.

I use a file guide of sorts but I see the need for another picture that I should have included. I'll try and get that done in the next couple of days.

Keith
 

kirk

New Member
Guys, I don't want to clutter up Keith's tutorial but I just wanted to say that I'm the lucky owner of this knife and the lockback action is quite impressive - like the proverbial Swiss watch. It locks open with a distinct click and is silky smooth. Loving it
 

K R Johnson

Well-Known Member
Keith,

A handsome knife! When you file the rat tail on the bolster do you use a jig or file guide?

Jay
Here's my filing guide for rat tails, or fluted bolsters. I have a bar of aluminum with a 3/32" stud in one end.


I set the pivot hole on the stud, lay a lathe bit alongside the bolster and clamp it there. I run the file alongside the bit until I have a good track started, then remove the bit and finish the flute.
 

Sticks

Well-Known Member
Keith,

Thank you for posting these pictures and comments. I was wondering how to make sure the file didn't get off to the wrong start on the rat tail and be even on both bolsters.

Jay
 

K R Johnson

Well-Known Member
Keith,

Thank you for posting these pictures and comments. I was wondering how to make sure the file didn't get off to the wrong start on the rat tail and be even on both bolsters.

Jay
After you take the guide away, DO NOT let the file slip. It will cut into the edge of the frame so there will be a gap between the scale and the frame. The only solution is to clamp the frames together and grind until the divot is gone. Ask me how I know this. :3:
 

Don Robinson

Well-Known Member
I've been impatiently waiting thru all this great tutorial for you to show how you file the flutes so perfectly.

Thanks a million!
 

Sticks

Well-Known Member
After you take the guide away, DO NOT let the file slip. It will cut into the edge of the frame so there will be a gap between the scale and the frame. The only solution is to clamp the frames together and grind until the divot is gone. Ask me how I know this. :3:
Ha! I've noticed that with these "slipjoints" and folders, one little slip results in a cascade of corrections! Fix one part and the next no longer fits right. Do you use a 14" wheel for the primary grinds?
 

K R Johnson

Well-Known Member
Guys if you go back to post #38 & 39 you'll see that I left a pretty important part out of this knife build. I'm making another lockback right now so I took a few pictures and I'll try and fill in the blanks.

This picture shows one of the frames with the blade and lockbar pinned to it and the spring compressed to hold the knife locked. At this point you can move the vise grips until you are satisfied that the spring has plenty of power to hold the lockbar in position. I always put a little more than enough pressure on because you can weaken a spring but you can't easily make it stronger. Scribe a line on each side of the spring.


Now I've traced the edge of the blade where it'll be when the knife is closed and drawn a sketch of what the back spacer will look like. (There are a couple of extra lines there you can ignore).


Next I start making the back spacer from a scrap of 410 stainless. Leave plenty of material outside the frame so you have room for adjustments



Now I clamp the spacer in place using the previously scribed lines to adjust spring compression and figure out where to drill holes. Notice the fresh layout dye and I've scribed lines next to the spacer.


The holes are drilled.


I use 3/32" roll pins to accurately hold halves together for transferring holes to the other side.


Here it is with the parts pinned together


And after grinding away everything that doesn't look like the back of a knife


And what it should look like inside


And with the blade installed.



Now the kick needs to be adjusted to drop the blade tip into the frame.
I hope this properly fills in the blanks. Thank you, Keith
 

Sticks

Well-Known Member
Thanks Kieth! There was a lot more work to that piece than I would have thought. My buddy Ed and I chatted with you at the Badger Knife Show and enjoyed meeting you. You were very generous with advice and encouragement on our folder builds!

Jay
 

K R Johnson

Well-Known Member
Thanks Kieth! There was a lot more work to that piece than I would have thought. My buddy Ed and I chatted with you at the Badger Knife Show and enjoyed meeting you. You were very generous with advice and encouragement on our folder builds!

Jay
Hi Jay,

It was a pleasure meeting you at the show. Keep at those folders.

Keith
 
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