Basic Disassembly, Repair & Reassembly of a Jack Knife.

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orvet
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Re: Basic Disassembly, Repair & Reassembly of a Jack Knife.

Post by orvet » Sun Nov 26, 2017 10:43 pm

The first thing that comes to mind is that it is an unnecessary expense.
The second thing that comes to mind is you will see a great increase in the number of cracked handles because if the tapered pin perfectly fits the holes then the first time you put the hammer on the end of the pin to peen the pin you will be exerting outward force the entire length of the handle material.

I make sure I have at about 0.005” clearance between my pin and the wall of the hole through a bone handle. Sometimes even more because when you tap the end of the pin to peen it, it can swell further down the pin. All of the outward pressure is not contained at the top where I want the head to form, but some of that pressure is directed outwards further down the hole and that’s why I always say drill a hole that is larger than the pin stock I am using.
For example for a 1/16” pin I use a #51 drill. The 1/16” pin is 0.0625” and the #51 drill is 0.0670” – this allows 4 ½ thousands clearance. This is adequate for a 1/16” pin but if I were using a 3/32” pin I might leave a little more clearance than 5 thousandths especially if it is a brittle material like bone and most especially if I were peening the head of the pin instead of spinning it.

Those are my initial thoughts on the subject.
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Re: Basic Disassembly, Repair & Reassembly of a Jack Knife.

Post by americanedgetech » Sun Nov 26, 2017 11:35 pm

I 100% get your points, and have thought about them before posting the question.

Assume your taper, (in your handle material) and pin match exactly down to the original pin hole in the liner, and your material is a hard stone that can not tolerate pressure. Let's say quartz crystal. Setting (gluing) the stone, and inserting the pin thru the handle into the liner to be silver soldered "could" be the easiest, and dare I, best way to set a brittle material. Maybe?

For softer materials I agree that this would be a lot of effort, and expense (tools, material, time), and why re-invent the wheel?
For brittle materials I see this as a plus but I have more thoughts than experience. That's why I post my thoughts. :lol:
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Re: Basic Disassembly, Repair & Reassembly of a Jack Knife.

Post by orvet » Mon Nov 27, 2017 1:31 am

americanedgetech wrote: Assume your taper, (in your handle material) and pin match exactly down to the original pin hole in the liner, and your material is a hard stone that can not tolerate pressure. Let's say quartz crystal. Setting (gluing) the stone, and inserting the pin thru the handle into the liner to be silver soldered "could" be the easiest, and dare I, best way to set a brittle material. Maybe?
I guess my question would be; Why do you want to use a material that cannot tolerate pressure as a knife handle? The first time it gets dropped on a hard surface the pressure created from the shock of the drop will break the handle. ::shrug::
Why would you go to the extra time and effort, (which in manufacturing equals money), to use such a fragile material that the knife could never be an EDC?
A knife like that would be a safe queen only. If you you’re making a safe queen just glue the handles on and don’t worry about pinning them.


If you really believe that method will work the best, then do it, but unless you are going to use this method then this has only been an exercise in mental gymnastics! All the what if this, and what if that questions are fine and dandy if you are going to using those methods, such as tapered pins for handles. But if you’re not going to use those methods it’s a waste of time for everyone.

Cutler’s have been using round pins for hundreds of years and they work perfectly well.
Why beat your head against the wall to reinvent a more costly wheel that may or may not work?
Especially when it will likely be cost prohibitive from a manufacturing standpoint?
It doesn't make sense to me.
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Re: Basic Disassembly, Repair & Reassembly of a Jack Knife.

Post by americanedgetech » Mon Nov 27, 2017 1:51 am

:lol: :lol:
Good points for sure.
It's that stone handle knife that set me thinking about this, and yep, I have the seller with the tapered pins bookmarked.
They are actually for clock repair. He sells a hundred assorted sizes for around 15 bucks on FleaBay

Bill DeShivs said something that stuck with me. (paraphrased) "Learn all the methods, and use the ones you feel comfortable with."
You've noticed yourself that I analyze everything until I throughly understand the process, and the forces at play. Part of my process is looking for improvements where (most often) they are not needed but they still may be an improvement. ::hmm::

I get the safe queen analogy and for sure I'd like to build myself one. After all it will most likely be less fragile than a dropped cell phone, and it'll cost me far less. :lol:
In fact I'll make that a personal challenge for myself. A quartz crystal handled folder. ::super_happy::

I appreciate your patience, and your input Orvet. I know I have a long way to go. ::handshake::
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Re: Basic Disassembly, Repair & Reassembly of a Jack Knife.

Post by Lansky1 » Thu Dec 24, 2020 12:46 pm

orvet wrote:
Sat Nov 17, 2012 1:46 pm
Not to be cryptic, but pin stock is where you find it.

In other words, while it isn't exactly everywhere, it is more common than one would first think.
Brass pin stock is probably the easiest to find. I get most of mine through my local Ace Hardware Store. Most of it they carry in 3’ lengths and sell for less than you will pay for 2’ of the same brand from other sources. I have also found a good supply of brass & stainless steel pin stock at my local True Value Hardware stores as well.

Many hobby stores, both online & local, will carry brass pin stock, sometimes stainless steel and occasionally a limited supply of nickel silver.

The best variety of sizes of nickel silver pin stock that I have found is at Jantz Supply. I find their website somewhere between abysmal and impossible to use, but if you call them and ask for a print catalog you can see the sizes they have.

Here is a link to a thread I posted some time ago on sources for pin stock:
http://www.allaboutpocketknives.com/kni ... 37&t=23455


When I must have a certain size pin stock and don't have anything close to the proper size, I will turn down a piece of larger stock by chucking it in the drill press and taking it down with a file & sandpaper to the proper size.
Another method is to chuck the stock in a drill and spin the stock against a running belt sander. That takes it down fast, but it easy to take it down too far unless you are careful. It takes some practice to get proficient at this method.



Hope this helps.

Hi knife guru's ... I bought a Case small gunstock with the intention of removing the tiny pen blade. I'm reading all the information here (tremendous resource - thx to all for posting tips / methods). I'm a Case guy and need to order some pin stock. Can anyone please give me a few common pin diameters that I'll need for reassembling common modern Case patterns ? I was hoping to only buy a few sizes to start with & build up my stock if I take to this ... many thanks !!

John (PS - I'm sure glad for AAPK - I was going to try and just punch out the pins with the hopes of re-using them ... seems that's not possible as the pins need to be cut & would have been an expensive learning experience. Just want to confirm though - is it really THAT difficult to punch out the center & 2 bolster pins rather than cutting them to get the knife apart ??)
pffffft that's not a knife ......... now THAT'S a knife !! Crocodile Dundee

John

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Re: Basic Disassembly, Repair & Reassembly of a Jack Knife.

Post by Jeffinn » Sat Dec 26, 2020 3:41 pm

Lansky1 wrote:
Thu Dec 24, 2020 12:46 pm
Hi knife guru's ... I bought a Case small gunstock with the intention of removing the tiny pen blade. I'm reading all the information here (tremendous resource - thx to all for posting tips / methods). I'm a Case guy and need to order some pin stock. Can anyone please give me a few common pin diameters that I'll need for reassembling common modern Case patterns ? I was hoping to only buy a few sizes to start with & build up my stock if I take to this ... many thanks !!

John (PS - I'm sure glad for AAPK - I was going to try and just punch out the pins with the hopes of re-using them ... seems that's not possible as the pins need to be cut & would have been an expensive learning experience. Just want to confirm though - is it really THAT difficult to punch out the center & 2 bolster pins rather than cutting them to get the knife apart ??)
You might get a better response if you post this in the Knife Repair and Restoration section. I don’t generally work on Case knives so I can’t help you with your question but there’s some folks in the repair group that should be able to help.
Jeff
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Re: Basic Disassembly, Repair & Reassembly of a Jack Knife.

Post by Reverand » Fri Jan 01, 2021 8:08 pm

On some knives I have been able to remove the flared head on one side of a pin, using a ball burr on a Dremel. Then I drive the pin out.
I have not been able to do this on a Case pivot pin get.
That doesn't mean that you won't succeed where I failed, so you should try.
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Everything else is just a hobby.

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Re: Basic Disassembly, Repair & Reassembly of a Jack Knife.

Post by orvet » Sat Jan 02, 2021 3:33 pm

Lansky1 wrote:
Thu Dec 24, 2020 12:46 pm

Can anyone please give me a few common pin diameters that I'll need for reassembling common modern Case patterns ? I was hoping to only buy a few sizes to start with & build up my stock if I take to this ... many thanks !!

Just want to confirm though - is it really THAT difficult to punch out the center & 2 bolster pins rather than cutting them to get the knife apart ??)
The size of the pivot pin depends on the size of the knife, I have worked on Case knives but not enough to memorize the sizes of all the pins they use.


As to your second question: It is possible and even fairly easy IF you have the technique, practice and proper tools.
The pivot pins are tapered and you will need to drill into the pin and remove enough pin material so the sides of the pin can collapse inward when you drive the pin out.
If you drive the pin out without removing enough of the center you can widen the taper so that the new pin won't stay in unless you find the proper size broach to re-taper the pin hole.
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Re: Basic Disassembly, Repair & Reassembly of a Jack Knife.

Post by Lansky1 » Sat Jan 02, 2021 5:39 pm

orvet wrote:
Sat Jan 02, 2021 3:33 pm
Lansky1 wrote:
Thu Dec 24, 2020 12:46 pm

Can anyone please give me a few common pin diameters that I'll need for reassembling common modern Case patterns ? I was hoping to only buy a few sizes to start with & build up my stock if I take to this ... many thanks !!

Just want to confirm though - is it really THAT difficult to punch out the center & 2 bolster pins rather than cutting them to get the knife apart ??)
The size of the pivot pin depends on the size of the knife, I have worked on Case knives but not enough to memorize the sizes of all the pins they use.


As to your second question: It is possible and even fairly easy IF you have the technique, practice and proper tools.
The pivot pins are tapered and you will need to drill into the pin and remove enough pin material so the sides of the pin can collapse inward when you drive the pin out.
If you drive the pin out without removing enough of the center you can widen the taper so that the new pin won't stay in unless you find the proper size broach to re-taper the pin hole.
Thank you Dale - appreciate that advice about hollowing out the pins before punching out. I'm curious about the tapered pivot pins (never knew that) ... do you have to taper the replacement pivot pin rod stock to match the internal taper ? Also, was wondering if there is a rule of thumb on which side normally has the larger end of the tapered pin - pile or shield side (this would determine which side I would want to punch from) ? Thanks again !

John
pffffft that's not a knife ......... now THAT'S a knife !! Crocodile Dundee

John

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Re: Basic Disassembly, Repair & Reassembly of a Jack Knife.

Post by orvet » Sat Jan 02, 2021 6:04 pm

The pins are tapered because they are peened in place and are mashed out to assume the shape of the tapered hole.
To put in a new pin you only need a straight piece of the proper size pin stock, (it is untapered).
The mistake many people make is to assume they can I put the straight pin in the hole and just peen down the pin, file or sand off the excess, and they are good to go. In many cases that will work. But if the taper had been messed up on either side, the pin may loosen.
To prevent this you need to reestablish the taper at outside of each hole in the bolsters. It only needs to be a few thousands taper. It requires a broach or a tapered reamer and just need to go deeply the bolster, a few thousands of an inch is preferable.
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Re: Basic Disassembly, Repair & Reassembly of a Jack Knife.

Post by Lansky1 » Sat Jan 02, 2021 10:54 pm

orvet wrote:
Sat Jan 02, 2021 6:04 pm
The pins are tapered because they are peened in place and are mashed out to assume the shape of the tapered hole.
To put in a new pin you only need a straight piece of the proper size pin stock, (it is untapered).
The mistake many people make is to assume they can I put the straight pin in the hole and just peen down the pin, file or sand off the excess, and they are good to go. In many cases that will work. But if the taper had been messed up on either side, the pin may loosen.
To prevent this you need to reestablish the taper at outside of each hole in the bolsters. It only needs to be a few thousands taper. It requires a broach or a tapered reamer and just need to go deeply the bolster, a few thousands of an inch is preferable.
Thanks Dale for taking the time to explain the tapered aspect of the ends of the pins - appreciate it ::tu::
pffffft that's not a knife ......... now THAT'S a knife !! Crocodile Dundee

John

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Re: Basic Disassembly, Repair & Reassembly of a Jack Knife.

Post by orvet » Sun Jan 03, 2021 1:04 am

You're most welcome John. ::tu::

It really is kind of a deceptive term when I stop to think about it. Ever since I started working on knives I've always heard them described as tapered pins. But in most cases the pens are not tapered when they are installed, they are tapered when they are peened to fit into the tapered hole.
Thinking back to when I first started working on knives, I don't think I understood the term the first time I heard it either. Someone had to explain it to me.

There were some larger 1/8" pins Schrade used which were tapered on one side. I think that was to make it a little easier to install the pin. There is a lot more metal to move in a 1/8" and if you only have to peen one side it's much easier and there's less chance of making mistake.
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