Changing scales

[ExtraBaconPlease]

Hey everyone!

How are the scales attached on the FK and LC? I'm thinking of maybe making a pair of wood scales, probably for the FK but am not 100% convinced of my skills...yet.

Is it as easy as 1, 2, 3 screws?

 

[ni1s]

Hey everyone!

How are the scales attached on the FK and LC? I'm thinking of maybe making a pair of wood scales, probably for the FK but am not 100% convinced of my skills...yet.

Is it as easy as 1, 2, 3 screws?

For The fk at least it's 1, 2, 3 screw.

 

[TRfromMT]

Trust me when I say that's where the easy part ends

Juse kidding... I'd absolutely encourage anyone to give it a try. I've made "a few" custom wood scales and if I can help with any tips and tricks let me know. My FK (and future EDC) will be clad in matching wood scales someday, probably koa or curly maple. Just haven't got to them yet...

If I can offer one suggestion, don't use a highly burled wood for these (burl scales should be glued and pinned, in my opinion).

 

[JustinFournier]

If you are gonna do it, you have to start with the fasteners of course. I suggest you only take them out from one side to start, the back side. Note, they will be different lengths, and secured with loctite so make sure you note which screw came from where.

Also, make sure you have a brass brush or similar to clean the screws up before you but them back in.

Once you get the screws out on the back side, see if you can gently persuade the pins out with the mark side screws still in them. If that is the case, you are golden. They have a tight interference fit. Alternatively you can try and gently massaging the scale off the back side pins. If that works, you are also golden. You may need a combination of the two. Pins out and scale up.

If you start to struggle with it, I would suggest you just stop as it's going to be quite an expense for you to get anything replaced due to your geographical area. Nathan epoxies almost all his wood handles in place, the few that he does, and like Tony said, this is not the best candidate for wood though it is completely possible. Nathan also laminates his wood onto micarta or G10 liners for stability. So it is possible to do with not damage or evidence that it was done, but it might take a little patience and time.

Good luck!

 

[ExtraBaconPlease]

Thanks for the help guys!

Justin, are the FK handles pinned too? I was under the impression it was just the screws and some loctite?

 

[on_the_edge]

Thanks for the help guys!

Justin, are the FK handles pinned too? I was under the impression it was just the screws and some loctite?

You are correct on the FK: screws and loctite with a loose female "pin" that they screw into. The pins slide out easily. There are no other pins, just the three of them.

 

[JustinFournier]

Thanks for the help guys!

Justin, are the FK handles pinned too? I was under the impression it was just the screws and some loctite?

Well, the "pin" is basically a female threaded barrel pin (tapped dowel pin?) the screws go into from each end. The pin passes through the tang. The pins are used to locate the scales and take all of the load from use, the screws just hold them down in place. I have changed about half a dozen handles on various models, none of which came off easy. None were loose. They were all fit extremely tightly, and all went back together well. No marring, or damage to anything so it's completely possible. Note I have a very expensive set of WIHA hex keys and some cheap ones might not give you the same result.

Edit: Moving question to new post.

 

[JustinFournier]

The pins slide out easily.

I see you had a different experience Chris. I wonder if you are speaking of the knife sent to you for destructive testing that was a reject. Was that the one?

 

[ExtraBaconPlease]

You are correct on the FK: screws and loctite with a loose female "pin" that they screw into. The pins slide out easily. There are no other pins, just the three of them.

Well, the "pin" is basically a female threaded barrel pin (tapped dowel pin?) the screws go into from each end. The pin passes through the tang. The pins are used to locate the scales and take all of the load from use, the screws just hold them down in place. I have changed about half a dozen handles on various models, none of which came off easy. None were loose. They were all fit extremely tightly, and all went back together well. No marring, or damage to anything so it's completely possible. Note I have a very expensive set of WIHA hex keys and some cheap ones might not give you the same result.

Edit: Moving question to new post.

I understand perfectly now. Thank you both!

 

[on_the_edge]

I see you had a different experience Chris. I wonder if you are speaking of the knife sent to you for destructive testing that was a reject. Was that the one?

That would be the one. I too have a set of Wiha tools and personally found that particular knife to be no issue. Not sure if taking apart a lot of other knives over time and years of getting into every conceivable type of computer helped, but it probably didn't hurt.

May I ask--why do you feel the FK is not a good choice for wood scales? Or are you only talking only about the LC? I have plans to put some very nice wood scales on my FK.

 

[JustinFournier]

That would be the one. I too have a set of Wiha tools and personally found that particular knife to be no issue. Not sure if taking apart a lot of other knives over time and years of getting into every conceivable type of computer helped, but it probably didn't hurt.

My guess is the way your knife was assembled had to do with it being a reject. For sure, normally the pins are not supposed to be loose. They are load bearing and used to locate the scale to a tight tolerance interference fit, not compatible with loose.

May I ask--why do you feel the FK is not a good choice for wood scales? Or are you only talking only about the LC? I have plans to put some very nice wood scales on my FK.

Well, like Tony said, a burl should be glued and pinned ideally. It can be laminated to a liner, then pressed gently and then screwed on, but it's much harder. Just pin and epoxy, then when there is a little epoxy that oozes out, you can take it to the grinder and shape then finish them as you want. Go slow and be careful and you will be OK. You will get a great fit and little risk. This could be done to a FK of course, but is not a great idea to make your first set to go on the way the normal scales do.

Nathan has a wood scale reject rate that is high. I am not sure how high, but I would say more than 50% of them get tossed. That is with backing them on a liner, and because of his process of course, vs a grinder, which is much easier, but trying to make a set of wood that are interchangeable with the factory ones is a tough job. Anything is possible, but IMO that is not an easy place to start. That's all.

 

[on_the_edge]

My guess is the way your knife was assembled had to do with it being a reject. For sure, normally the pins are not supposed to be loose. They are load bearing and used to locate the scale to a tight tolerance interference fit, not compatible with loose.




Well, like Tony said, a burl should be glued and pinned ideally. It can be laminated to a liner, then pressed gently and then screwed on, but it's much harder. Just pin and epoxy, then when there is a little epoxy that oozes out, you can take it to the grinder and shape then finish them as you want. Go slow and be careful and you will be OK. You will get a great fit and little risk. This could be done to a FK of course, but is not a great idea to make your first set to go on the way the normal scales do.

Nathan has a wood scale reject rate that is high. I am not sure how high, but I would say more than 50% of them get tossed. That is with backing them on a liner, and because of his process of course, vs a grinder, which is much easier, but trying to make a set of wood that are interchangeable with the factory ones is a tough job. Anything is possible, but IMO that is not an easy place to start. That's all.

Understood. I guess I should be clearer. The pins on the knife that I removed the scales from were not "loose". I just did not find them particularly difficult to remove. I never tried to put them back into the handle for obvious reasons.

Also, I see your point about removable handles. I do not want removable handles on mine, but want them to be permanent with pins of some type (I have not yet decided what material I'm going to use for the pins--damascus or maybe CF or ...). Yes, they will be glued with a product used and highly regarded by knife makers. And I have made scales before so I am not too worried about botching it. Time, patience, perseverance, some basic knowledge, skills and tools, and a little bit of luck hopefully will come together to make the project a success.

 

[JustinFournier]

Understood. I guess I should be clearer. The pins on the knife that I removed the scales from were not "loose". I just did not find them particularly difficult to remove. I never tried to put them back into the handle for obvious reasons.

Also, I see your point about removable handles. I do not want removable handles on mine, but want them to be permanent with pins of some type (I have not yet decided what material I'm going to use for the pins--damascus or maybe CF or ...). Yes, they will be glued with a product used and highly regarded by knife makers. And I have made scales before so I am not too worried about botching it. Time, patience, perseverance, some basic knowledge, skills and tools, and a little bit of luck hopefully will come together to make the project a success.

Yeah that makes sense. The pins are doable for sure, as I said I've done several with no problem, so I know It's totally doable if one is careful and has a good mechanical understanding.

On the wood, yes if you do it that way, and keep your scales as a reference you should be able to get it just the way you want them. I would love to see a WIP if you want to make one!

I am anxiously awaiting to see what Tony turns out.

 

[Nathan the Machinist]

The holes on the tangs and the scales are located on CNC with circular interpolation then reamed to size. The location relative to each other is accurate to a fraction of a thousandths of an inch and the diameter is accurate to about a thou. The scales have some give (compared to steel) and are actually reamed a little over size because the holes shrink one or two thousandth's of an inch after reaming. The steel is reamed with a .2510 reamer, but as the tooling wears that hole can close up to .2500 before changing tooling. So, the tang hole is .250-.251, a total spread of .001".

The pins are turned here and the typical range is .2495-.2505, so there is a total spread of about one thou.

This means that some holes in the tangs can be as large as one thousandth of an inch over nominal (1/4") and some pins can be half a thou under nominal, so the pin could have as much as .0015" diametrical clearance. That's not a lot of clearance (a little less than the diameter of a human hair) but that pin will fit that hole without much effort. We try to avoid that much clearance.

On the flip side, some tang holes can be .2500" (nominal) and some pins can be as large as .2505" (half a thou over nominal) so there is half a thou interference. This is a light press fit and you have to force or tap them together. When we get into a batch with that much interference we'll usually put those pins aside and use some from another batch from the smaller end of the tolerance.

So, we aim for as close to line-to-line as we can, but accept that there are limits to the level of precision we can put into the pin/tang fit. So, some are very tight, some are less tight. All are "snug" with little or no slop. You may find yours can be removed without a lot of trouble, or you may find special tooling and techniques are required to pull yours apart. They're not made for ease of disassembly, but it's usually pretty do-able.