First Slip Joint

chavez556

chavez556

Joined
Jan 10, 2011
Messages
1,448
I want to make my first folding knife this month. I have decided to go the slip joint route to start, and I have a few questions.

I wanted to use a AKS 3/16" pivot. What are your thoughts on this. Would it be easier to use pins and a bushing for the pivot?

Another question. Should I use small bronze washers, for smoother action? I also considered bearings???

Btw I will try to post some WIP photos.

Thanks.

Nick
 
Sorry I cant answer any of your questions Nick but am looking forward to seeing your project. I have come to find my favorite edc knife is a slipjoint
 
Old traditional slipjoints are typically a 3/32" pin through the bolsters and blade. One of the ways the more modern version are made uses a 3/32" x 3/16" bronze bushing about .001" thicker than the thickness of the blade, with the liners mill relieved at the pivot area to reduce fiction and eliminate scratches on the tang of the blade.

I've made a few slipjoints in the old traditional manner and am now trying my hand at one using the more modern methods. I got my bushings from Knife and Gun Supply, so far it's the only place I've been able to find them.

http://www.knifeandgun.com/ProductDetails.asp?ProductCode=B3
 
I went and ordered some bushings.

Wow I really hate when a company charges $15 shipping to send 2 ounces of supplies.

Anyway below is just a rough cad print out of my design. Obviously there will be some mods, but I wanted to get the parts cut out, so I can get the ball running.

I made an XL version too. I'm going to make the small version first.

Nick
uploadfromtaptalk1410239187003.jpguploadfromtaptalk1410239195525.jpg
 
I first add a disclaimer that I've only successfully made ONE slipjoint thus far, but one thing imediately jumps out at me with your design: There's just not very much meat around your center spring pin. I think you risk a broken spring if that drawing is in fact to scale.

Besides that, your spring seems a little thin overall for the size of the blade, I.E., your pull may end up being a little lighter than you want it to be.
 
I noticed that. You think adding .020 would help? Basically adding that amount to the top Li en of each part?

Thanks
Nick
 
Go buy Don Robinson's book, "Slipjoints My Way." Dont just go into this all willy nilly or you'll be disappointed.
 
Brian is correct, I have Don Robinson's book, Adrian Harris's book on slipjoint repair and restoration and Chris Crawford's tutorial that I downloaded from his website and I have learned valuable information from each one.
 
Also, your sorting has no tension in it as drawn. It won't hold the blade open or closed like that.

Go spend $30 and buy a case sodbuster, cut it apart and go from there. You understand what I mean. If not, I'll try to get a picture for you if I can find one of my torn apart blades.
 
I have read Chris Crawford tutorial a few times.

Unfortunately my bandsaw blade broke so everything is on hold for now.

I'm working on these 3 till I get a new blade. uploadfromtaptalk1410477146029.jpguploadfromtaptalk1410477156778.jpg
 
like Brian said go buy a case or uncle henry. it don't matter if it is from a pawn shop and has a broken blade the tang and springs are what you are most interested in. A 3/16 pivot is going to leave no material in the tang for strength except on larger knives. If you insist on using a pivot use 1/8th inch bushings. Tony Bose is the only top tear slip joint maker I know of who use bushings. if you just have to use bushings use screws to assemble the knife.
 
Bill Burke said:
like Brian said go buy a case or uncle henry. it don't matter if it is from a pawn shop and has a broken blade the tang and springs are what you are most interested in. A 3/16 pivot is going to leave no material in the tang for strength except on larger knives. If you insist on using a pivot use 1/8th inch bushings. Tony Bose is the only top tear slip joint maker I know of who use bushings. if you just have to use bushings use screws to assemble the knife.
Click to expand...
Bill,

You are a badass. Thanks for the advice.

Quick question,

Do you mean Bose uses bushings and a 1/8" pivot? I have decided to go with a 3/32" pin and a bushing for the first one.
If I do decide to make the larger version, do you think I should use a pivot and a bushing ?

Should i use nylon washers ?

Thanks,

Nick
 
Bill Burke said:
like Brian said go buy a case or uncle henry. it don't matter if it is from a pawn shop and has a broken blade the tang and springs are what you are most interested in. A 3/16 pivot is going to leave no material in the tang for strength except on larger knives. If you insist on using a pivot use 1/8th inch bushings. Tony Bose is the only top tear slip joint maker I know of who use bushings. if you just have to use bushings use screws to assemble the knife.
Click to expand...
Bill,

You are a badass. Thanks for the advice.

Quick question,

Do you mean Bose uses bushings and a 1/8" pivot? I have decided to go with a 3/32" pin and a bushing for the first one.
If I do decide to make the larger version, do you think I should use a pivot and a bushing ?

Should i use nylon washers ?

Thanks,

Nick
 
chavez556 said:
Bill,

You are a badass. Thanks for the advice.

Quick question,

Do you mean Bose uses bushings and a 1/8" pivot? I have decided to go with a 3/32" pin and a bushing for the first one.
If I do decide to make the larger version, do you think I should use a pivot and a bushing ?

Should i use nylon washers ?

Thanks,

Nick
Click to expand...

Tony uses a 3/16" OD bushing with a 3/32" pin.. I use bushings some, but usually not. I also use .005" bronze washers and make my blades .010" thinner than the spring.

As said, buy a cheap slip joint and use it as a pattern. There is no better way!
 
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