relieving slip joint liners

Ryan Minchew

Ryan Minchew

Joined
Sep 29, 2005
Messages
580
One of the reasons I've put off messing with slip joints for so long is I could not relieve the liners and still have them decent looking. I tried dremel, stones, drill press, and scrapers and they all looked like I hacked at it with a chain saw. Tonight I laid out my liner then place electrical tape over the inside of the liner. I took a scrap liner and made a pattern of the area that I did NOT want to remove. I laid that over the electrical tape and cut it out with a knife. I then removed the pattern and the electrical tape that had been cut leaving the steel exposed. My next step was to use my homemade etcher and etch the area I wanted relieved. It seemed to work well. My steel pattern was a little rough, I didn't know how it would work so I didn't spend any time cleaning it up with files and sandpaper to smooth the edges and what not. Here's pictures of what I did. I"ll clean up the jagged parts of the pattern and smooth it out some, but I think this is going to work. I don't think the etched area looks horrible compared to my hacking at it with a dremel. Let me know what you think. Ryan

Please ignore the divots. I spot welded my bolsters on and I've got to figure why it's leaving divots.


knives440.jpg

knives439.jpg
 
What you are doing is totally unnecessary on a properly built knife.
 
Care to elaborate? I can't think of another way to stop from scratching the tang unless I use washers. If I use washers my blade has to be considerably more thin than the spring.
 
Ryan,
Many makers like Tony Bose and Bill Ruple relieve their liners like you did.
Tony Bose uses a bronze busing and leaves it .001 thicker than the blade for space.
You could use washers and the difference between the blade and spring could be .010, and put one .005 on each side.

Are you spot welding before or after you relieve the liners?
 
Knives have been made for a couple hundred years without "relieved" liners. Theoretically, relieving or using washers on the liners makes the blade more prone to wobble, BTW.
 
If Peened correctly there will be no wobble. basicly the only thing this does is keeps the ricaso of the slipjoint from getting scratched up so much. it doesnt bother the preformance of the knife.

Your getting divots because your getting it too hot when your spot welding it. try it on some scrap with a bit less time on the trigger youll see what im talking about.
crap I hate typing before coffee
 
I certainly understand knives have been made for years without them. They've also been made without epoxy, they've been made without new powder steels, been made without kmg grinders but now people use them. Obviously several top makers aren't making knives properly, but they sure have a lot of people convinced they do.

Chuck I tried grinding the blade down thinner than the spring, but I couldn't get it within the tolerances I liked. Do you have any tips? Mine alays end up way thin on one end then thick on the other. I did my spot welding before I relieved the liners. There were actually 4 divots but the etching wiped some of them out. I think I'm going to try to smooth the points on the spot welder I think I can stop the divot problem.
 
Thanks Rusty ill try less trigger pull. I have a 220 volt welder do you think I would be better off with the 110? Possibly stop it from getting too hot? Thanks.
 
Bill is right...it's not necessary to mill tang relief to make a good working knife. But, hand made knife buyers are kinda picky. They don't want scratches on the tang so that's why that area of the blade pivot is kept away from the liners.

You can do that easier with flat washers, like some people use on liner/frame lock folders. Bushings are better for other reasons though ;) ...it just takes more time and more tools.
 
My whole point of relieving the liners was to stop tang scratches. I don't like the way they look and I think the buyer of my knife should get a little extra detail if I have the ability to do so.

As far as the pivot itself I used the tony bose tutorial and bought a bushing lap from Bill Vining and it works great.
 
The thing about the washer is it's kinda hard to find a washer that is .005 or less with a 3/32" hole. you either have to make them yourself or dont use them.
 
You seem to have good control with the etching method Ryan. You may be onto something very useful. I have had my liners take off like a helicoptor in my milling machine.
I see Bill Burke and Bill Vining is here, Bills give us some thoughts. What do you do?
 
I bought a small mill and its a wonderful way to mill liners, you get great depth control and a smooth finish. I tried washers and you can always see a gap between the blade and liner, so I dont really like them. I got some shim stock and made my own washers.

I place the blade on a pin and mark the area where contact will be made when the blade is rotated. This way the relief ends when the blade will not make contact with the liner.

Dremmel works good for clean-up.
 
This is one of the reasons I went to looking for a way to relieve the liners. Right now in my 6 foot by 7 foot shop a mill is not really feasible. The washers I found were too thick like you mentioned. I would thin them some, and then I would thin on the blade some trying to reach the thickness of the spring. Working on the liners allowed me to keep tighter tolerances, and less gap between the blade and liners. Thanks Ryan
Rusty McDonald said:
The thing about the washer is it's kinda hard to find a washer that is .005 or less with a 3/32" hole. you either have to make them yourself or dont use them.
Click to expand...
 
Ryan,
The only part of the blade that needs to be flat and within tolerance is the tang. The rest gets ground away. For years before I got a surface grinder I thinned out stock on my platen on my grinder. I used a magnet to hold the blade. I only took material off on one side so I had the flat side to measure against. Take a little off, measure and repeat. Once you get it within a couple thousandths you can lap it flat on some sand paper and a piece of glass if you don't have a granite surface plate.

Or just do what your doing and relieve the liners and you can leave the blade and spring the same thickness.

Making washers is easy. You need a punch set and some washer material. You can then make whatever you want.

Bill,
How does relieving the liners make the blade more prone to wobble? The area where the tang rides is the same thickness as the rest of the liner. It is the area around the pivot area that is relieved so the tang does not get scratched.
 
I do it both ways but usually use .005" bronze washers and they work great in a slipjoint.
I've never had a complaint.
 
I relieve all my slip joint liners with my mini mill. I made a fixture the fit's in to my vice that acts as a rotary table. It is simply a block with a piece of bar stock pinned to it. The bar stock can rotate around the block. I fasten the liner to the bar, lower the mill, and rotate the bar. I'm sure there are other ways to do this but this is what works best for me.
 
Like Bruce, I think you are on to something with the etch. As far as Bill Burke, he has relieved the liners on the mill and I have seen him make and use bushings. I also use the milling machine to relieve my liners.
 
Bruce Bump said:
You seem to have good control with the etching method Ryan. You may be onto something very useful. I have had my liners take off like a helicoptor in my milling machine.
I see Bill Burke and Bill Vining is here, Bills give us some thoughts. What do you do?
Click to expand...

I am also relieving my liners on a mill but I am making my slipjoints with integral bolsters and liners. I do the relief cuts before milling out the area for the scales. I have a presision ground plate that pivots on another plate clamped in the vise.

One thing. Are you normalizing your bolsters and liners after spotwelding? This will need to be done if you are going to do any engraving or filing on the bolsters to avoid hard spots. Also on damascus bolsters you need to normalize and the harden to get the best looking etch with out the welds showing.
 
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