Build a linerlock

[flatblackcapo]

Thank you for taking the time to post this.It is a great help.

 

[Frank Niro]

An excellent presentation !!! Frank

 

[bear5177]

This is great! Thank you for sharing it!

 

[KHDaily]

I then clamp one of the bolsters to the liner with the blade edge of the dovetail pressed right up against it.

Drill through the screw holes. I plan to have a hidden pivot pin on this knife so I only drill a short way into the titanium through the pivot hole. Once you drill one side, flip it over and do the other bolster.

Where did you get those clamps you clamp your liners with???

Those are AWESOME!! Did you have those made or did you purchase them from somewhere?

 

[Don Hanson III]

Very well done!

 

[Gareth Bull]

Hey KHDaily

I'm glad you like them so much I got them from another SA maker. He makes the tapping guide and the pivot pins I use - talented guy!

 

[Aidansdaddy17]

Awesome. Very beautiful. Learning from the master. Less is more.

 

[Gareth Bull]

So, next chapter:

First thing I did was size the holes up to 4.2mm and ream them up to 4.5mm. Reaming makes for a smoother tighter fitting pivot hole - this is another thing that will help improve your action.

Now that the holes are the correct size to fit the pivot, we can accurately drill the mating hole for the ball detent. The location of this hole is very important and actually should be worked out in the design stages. In the image below, the ball needs to be within the red circle, if it's outside the ball will run off the blade during opening and closing which is not what you want.

Now that the first hole (the one in the lock that, the ball will be pressed into) is in place, assemble the blade, the locking liner and the spacer:

I get the blade into the position I want it to be in the closed position and draw a line along the back of the blade with a fine sharpie (you can scribe it but it means one more scratch you'll have to sand out!)

I then remove the spacer and rotate the blade a couple degrees past closed. You can see the gap between the spine and the sharpie mark:

This is how you want the parts when you drill through the liner, into the blade. This will cause the blade to be under tension in the closed position.

The tension I'm talking about is created by the offset. It's important because without it your blade would wiggle a little when closed poteintially baring the tip of your blade - definitely not what you're after.
Here's a close-up view of the offset you're looking to create:

Get this offset right and your blade will snap shut nicely and stay closed in the pocket.

Drilling into the blade:

You want to drill a minimum of half the diameter of the ball or more. Less could affect how the ball seats, you can drill all the way through if you like, I often do.

 

[Gareth Bull]

Now we can grind the blade (some makers do all their grinding post-hardening, I like to get a bit done before hardening, just personal choice here - do what you're comfortable with).

Technically you should be able to grind before leaping into folders, but I know I'm the impatient type so:
Grinding stages:
A: edge marked
B: grinding down to the edge at a coarse angle - this will mean your grit won't be hitting a perpendicular face and dulling your belt faster than necessary
C: Full hollow grind - the rough grind you did previously makes this easy to see and work down to. I only grind about 90% so you still want to see a little of the coarse angle.

Coarse angle:

From the edge:

Pre-hardening grind. I still need to crisp up the line and raise it a little but it's a good start, not much to fix. Note the thin silver line along the edge - that's what's left of the coarse angle I ground on earlier:

 

[fast14riot]

Superb write up, beautifully explained.


-Xander

 

[Maddogg774]

Very well thought out and delivered. Thank you for teaching this. It reminds me of when I first got Blackie Collins book on knife making.

 

[Allen Newberry]

Excellent tutorial!

 

[wolf5391]

you make this look so easy. wow!

I really need to get a 2X72 belt sander so I can hollow grind

 

[9blades]

Very good tutorial and excellent attention to detail I love the design!

 

[Gareth Bull]

Time to switch on the kiln! THIS was one of my best investments, not only does doing my own heat treat appeal to the OCD voice in my head but I can harden a blade up on a Friday night - might be a bit of a nerd.... oh well.

Green number is the kiln's current temperature, the red number is the target temperature. Little red ligh shows the elements are on

While the kiln is pre-heating I make a stainless steel foil packet - this stuff will cut you faster than anything I know - like a paper-cut on steroids I fold an over-sized piece in half then close up the long side first. I do two folds to make it airtight and tap the seam with a rubber mallet to make sure it's tight.

Now one of the ends, again, double folded:

Clean the blade with alcohol before placing in the packet:

Press out as much air as possible (it'll oxidize if you don't, this way the blade comes out a frosted grey that's very easy to polish)

The blade steel I'm using is RWL-34 so I heat to 1050*C and hold for 10 minutes, I then quench between two chilled steel plates (no photos - not enough hands!). As I type this it's chilling in liquid nitrogen overnight and I'll do the first tempering cycle (1 hour at 180*C) in the morning. I'll follow it with 4 more hours in the liquid nitrogen and another tempering cycle.

 

[vlaendr]

Gazza, that´s great WIP thread! And I´m even more impressed by your folders when I can see directly the amount of work involved.:thumbup::thumbup::thumbup:

 

[Gareth Bull]

Ok, now that the blade has been hardened and tempered, I grind the blade to final thickness and grind height:

Edge thickness:

It flares just before the run-outs but the majority blade is 0.25mm thick.

Now the grind is sorted it's time to make sure the blade is in the right position in the open and closed positions. Her's where I'm starting:

To raise the tip and align the spine of the blade to match the back of the handle, grind the area marked with the red line. Do a bit at a time and check constantly. As you get closer, it's advisable to step up to finer grits, this will make final polishing a breeze and stop you grinding too much away too fast

Close but not perfect - a little more to go:

Once you're happy with the open position you can start finalizing the closed position.
Starting point - note how the tip is sticking out the handle:

To drop the tip into the handle, enlarge the choil:

Again, do it bit by bit and check constantly until you're happy with the position and the tip is safely tucked away:

 

[Gareth Bull]

Now that I'm happy with the blade stopping positions, I size the pins to final lengths:
Oversize:

Quick sand on the disc sander:

(I do use 2 hands this is obviously posed)

Flattened off pins:

 

[Gareth Bull]

Now - the fun part The lock!

You can see here how much of an overhang I left - I'll need to grind that away:

Step one is to set the machine's rest to 8 degrees:

With linerlocks and framelocks you want your lock to be between 7.5* and 8.5* so I just go right in the middle at 8. Less than 7.5 degrees and the lock will bind on the blade, more than 8.5 and you run the risk of the lock accidentally dis-engaging if pressure is applied to the spine. 7.5 - 8.5 is the Goldilocks zone.

I put the flat of the tool against the flat, clean disc and line the rest up with the two white lines and lock it in place:

Now you can grind the excess off the lock. The notch I cut in earlier should make sense now, it allows you to grind only the lock face making things nice and neat:

Again, bit by bit is the name of the game - if you think I'm repeating myself, you'll understand when you make one - you must take the knife apart and put it together well over 100 times - no joke!

Success!!!! It's locking

Closed position:

Another view:

Now it looks like a knife! Just need to do various finishes and she'll be good to go:

 

[Big Chris]

This has been a great tutorial. I will look at this several times as I figure out how I want to make my folder.

Thanks a lot for taking the time to post this in depth.