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MTO Think Tank => Multitool.org R&D Section => Topic started by: Raukodur on July 14, 2013, 04:48:08 AM

Title: folding scissors = 2 interlocking folding knives?
Post by: Raukodur on July 14, 2013, 04:48:08 AM
Something like this possible?

(http://img24.imageshack.us/img24/8933/9j78.jpg) (http://imageshack.us/photo/my-images/24/9j78.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

Could have one plain edge, one serrated edge blade.
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: jzmtl on July 14, 2013, 05:00:43 AM
Don't see why not but it won't be a very good scissors, as you cannot curve blade toward each other like scissors do, or the sharp edges (especially if you add serration into the mix) will dig into and damage each other. And you have two chisel ground blade which many don't like.

Kershaw had something similar, one handle with two chisel ground blade, wasn't very popular if I recall.
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: JAfromMn on July 14, 2013, 05:08:05 AM
Here's a link to the Kershaw scissors

http://www.thekershawstore.com/Kershaw-Taskmaster-Shears-p/k1120.htm
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: jzmtl on July 14, 2013, 05:32:06 AM
Actually I was thinking of this one: http://www.google.ca/imgres?imgurl=http://i242.photobucket.com/albums/ff271/gorilla-bcuk/DSCF2568.jpg&imgrefurl=http://www.britishblades.com/forums/showthread.php?57783-Major-Folder-and-Fixed-Blade-Clearout&h=480&w=640&sz=74&tbnid=94HyUEyceNowlM:&tbnh=100&tbnw=133&zoom=1&usg=__X8Em0JEToZwJPciYdhoG2uHZHM8=&docid=DCF137KcJQvvaM&sa=X&ei=LxviUdv4MeK9ygHVx4DAAg&ved=0CDMQ9QEwAQ&dur=259

Also just remembered, Fiskars cut+more is similar in concept, think I even had a review of it somewhere.
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: JAfromMn on July 14, 2013, 06:39:29 AM
Oh yea I forgot about this one. I still have yet to try one of them.

 http://www.multitool.org/Knives/Folding-Knives/2007/06/27/kershaw-twocan.html
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: Raukodur on July 15, 2013, 02:08:16 AM
Don't see why not but it won't be a very good scissors, as you cannot curve blade toward each other like scissors do, or the sharp edges (especially if you add serration into the mix) will dig into and damage each other. And you have two chisel ground blade which many don't like.

Kershaw had something similar, one handle with two chisel ground blade, wasn't very popular if I recall.

Maybe this is very naive thinking, but wouldn't the blades sharpen each other as you used them in scissor mode?
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: Syph007 on July 15, 2013, 02:17:30 AM
Don't see why not but it won't be a very good scissors, as you cannot curve blade toward each other like scissors do, or the sharp edges (especially if you add serration into the mix) will dig into and damage each other. And you have two chisel ground blade which many don't like.

Kershaw had something similar, one handle with two chisel ground blade, wasn't very popular if I recall.

Maybe this is very naive thinking, but wouldn't the blades sharpen each other as you used them in scissor mode?

Well you'd need two chisel ground blades if you wanted to make something like this.  And the chisel grind would be on the outside, so I dont see how it would sharpen each other.  It would work like normal scissors as far as sharpening and they dont sharpen themselves.
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: jzmtl on July 15, 2013, 02:27:32 AM
Don't see why not but it won't be a very good scissors, as you cannot curve blade toward each other like scissors do, or the sharp edges (especially if you add serration into the mix) will dig into and damage each other. And you have two chisel ground blade which many don't like.

Kershaw had something similar, one handle with two chisel ground blade, wasn't very popular if I recall.

Maybe this is very naive thinking, but wouldn't the blades sharpen each other as you used them in scissor mode?

Since the two halves would be the same hardness one cannot remove material from another, theoretically anyway. You could do something similar to that kershaw, using thicker blade to resist the force separating two halves while cutting instead pretension like scissors. But you'd have to be real careful when sharpening to not remove any material from the non-ground side at all or the two edges won't meet anymore.
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: Grant Lamontagne on July 15, 2013, 01:01:55 PM
I could see this done with two fixed blades, but I'm not sure a folding blade would work as well, simply because the pivot pins would offset the blades and leave too much of a gap for them to act as scissors.

If they were fixed blades then a small guard could be designed to not only protect your hands when used as a knife, but then interlock to form scissors.  I think an ideal candidate knife for a prototype of this would be the CRKT Stiff KISS.

(https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcTkdGA87cmdojxAeUyNgzwpNkju5qrT9ZfWg50jnxPzYFkubBxZ)

The chisel grinds would make sure the blades met each other, they are slim/light enough that you could carry a pair of them in one sheath and not be weighed down and they have a hole drilled in the center of them (with a bolt added for balance and weight) that could be used as a pivot point.

The draw back is that you'd have tanto pointed scissors or you'd have to grind a new point onto them.

If the pivot mechanism could be designed in such a way as it would lock to another knife, and yet be identical it could benefit from being sold individually as well as a pair.  For example, set it up as each member of a group to have a good knife, but when they need scissors they just borrow their partner's knife, clip them together and instant scissors.

I'm not sure how feasible the idea is from a general market sense, but I think it would be an excellent experiment.  CRKT did something similar with the Crossover Game Shears (http://www.crkt.com/Crossover-Shear-with-Leather-Sheath?&search_id=460537) although for that it was a knife with an extra piece that turned it into scissors.  Kershaw's Two Can (http://www.multitool.org/Knives/Folding-Knives/2007/06/27/kershaw-twocan.html) also tried to merge knife and scissors into one tool, although I don't believe that has ever been super successful.

(http://www.multitool.org/cache/multithumb_thumbs/1___images_stories_Tool_pics_Twocan_3kt.jpg)

Def
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: AimlessWanderer on July 15, 2013, 02:59:13 PM
Another problem ... This might not be easy to put into words, but I'll give it a go.

As scissors the two blades need to be flush with the chisel grinds externally ground to ensure the cutting edges align. This could be done with a countersunk pivot head to ensure there isn't a proud surface as Grant highlighted, but that's the least of the problems. If you separate them you into two separate folding knives as planned, you end up with a CRKT Kiss mounted the wrong way, in other words the cutting edge is proud of the handle face, meaning safety issues!

Effectively, you will have a folding knife (or two) in your pocket with an exposed edge. Shielding the cutting edge with the handle in any way, would lead to interference between the two handles in scissor use. Add to that the fact that chisel edged blades will not suit many peoples knife requirements and you have a very bad idea which is unsafe and with poor performance.

This seems like a non-starter to me, and apart from being gadgety I cannot see any benefit from trying to do this in the first place  :think:
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: Grant Lamontagne on July 15, 2013, 03:53:43 PM
That's why I suggested the Stiff KISS, which is the fixed blade version.  The folding version just wouldn't work as you either have to have the blade facing out in your pocket making it unsafe, or have the cutting edges too far apart in "scissor mode" to do their job.  The blades would be about 1/8" apart.

As for it not having much benefit, I see this more of an EDC bag or emergency kit kind of thing, not a pocket or sheath carry kind of thing.  I have a small emergency bag strapped to the roll bar of my Jeep and it might be handy to have a couple of small fixed blades and scissors in there, but as the size of the bag is limited, I could see the benefit of merging them into one tool.  It would have a limited amount of interest, but it could be interesting.

Def
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: AimlessWanderer on July 15, 2013, 04:06:27 PM
The nearest I have seen to this concept (with fixed blades) is the CRKT Crossover Shears (http://www.crkt.com/Crossover-Shear), and I do actually own a pair. They are not a bad pair of kitchen scissors in fairness, but as a knife it's a real PITA to use due to having a chisel grind and having to tuck the scissors handle away, the grill scraper dulls the scissors blade in one area, using the screwdriver means you have a big stabby thing pointed at you .... but at least the bottle opener works  :tu:

The concept is a nice idea that doesn't work all that well in practice and the result is expensive with a very limited return in performance and versatility. A multitool should make life easier, but in actual fact using this tool makes it feel more complicated than it should be
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: livan on July 16, 2013, 11:42:35 AM


Scissors tool separates the known from at least the 19th century. And, almost all modern designs go from here(http://s51.radikal.ru/i132/1307/26/a2c7cdb43d2a.jpg) (http://radikal.ru/fp/2ba2b797649449d78c8b171cbf119296)
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: enki_ck on July 16, 2013, 01:46:12 PM


Scissors tool separates the known from at least the 19th century. And, almost all modern designs go from here
http://s51.radikal.ru/i132/1307/26/a2c7cdb43d2a.jpg

AK47 bayonet and sheath cutting tool. :tu: I always liked that one.
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: Grant Lamontagne on July 17, 2013, 11:06:00 PM
I sent this link to one of my contacts at CRKT and suggested that the Stiff KISS might be a good platform for trying this.  They have offered to provide a couple of Stiff KISS knives for experimentation, so I guess we now need a volunteer.

Who's willing to get their hands dirty and try to make it work?

Def
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: jzmtl on July 18, 2013, 01:30:59 AM
I was going to say somebody with a carbide drill, but it looks like the detent screw is easily removed, and all you need is a bolt and nut to make it work.
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: Syph007 on July 18, 2013, 01:37:15 AM
I thought Id mentioned in my last post but I didnt.  Im pretty sure you cant make scissors with straight edges.  Any Ive ever used or seen have blades slightly curved into each other.  That ensures they meet all the way along their cutting length.  If straight blades were used, you'd be able to cut up close to the handles, but near the ends, it would just bind.  For curiosity sake, I'd like to know if I'm right, but I just dont see the point in actually wasting time trying it.  I dont see the benefit in actually making a tool of two fixed blades, when in most countries you arent allowed to carry even one.
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: jzmtl on July 18, 2013, 01:51:34 AM
The knives may be stiff enough to resist any bend so no pretension is necessary ala tin snips, if they aren't a big vise and hammer should fix it.

I guess it's more of a proof of concept since fixed blades are easier to work on, if it works someone with the equipments can make it work on two folder with specially designed pivot bolts.
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: Grant Lamontagne on July 18, 2013, 02:01:11 AM
Fixed blades may be illegal in some places, but scissors aren't!  :D

Def
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: jzmtl on July 19, 2013, 02:18:53 AM
Nobody wants to get their hands dirty eh? I guess I'll take a stab at it if no one else.  :D
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: Grant Lamontagne on July 19, 2013, 02:41:12 AM
I guess we don't have as many adventurous modders as we thought!  :P

Def

Sent from a digital multitool
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: Metropolicity on July 24, 2013, 09:18:05 PM
I guess we don't have as many adventurous modders as we thought!  :P

Def

Sent from a digital multitool


Not true, but this is needs a lot more work than just a simple mod. I can see a few problems with it already.


If you take a closer look at scissors, the real cutting edge is not really a KNIFE edge. It's two sharp CORNERS passing past each other. Depending on the sharpness of these edges determines how sharp and easily the scissors get through material.


Any deviation from this precision passing of edges would negate any cutting ability and you'll get that thing when you try to cut a thick cord with $1 store scissors and it gets jammed in the middle and split.

Serrations, small ones add in this but they certainly are NOT knives.

A better or alternative way too look at this is more like a pair of bypass shears, where there is a stationary anvil and a knife (a real one) can rub against it and cut via that sharp cutting/crushing action. 

The Fiskars Cuts N More are 'knife' blades when separated but the knife edges suck and as scissors, they are also bad.

So...what to do? How about a pair of nice spring loaded scissors with a knife in the handle...ala Gerber Cable Dawg or GroundBreaker style.


I'd give this a collage try, but no promises.
Title: Re: folding scissors = 2 interlocking folding knives?
Post by: SirAri on January 09, 2017, 01:43:12 AM
I would recommend looking into something like these > http://www.coghlans.com/products/safety-scissors-8908

(http://www.coghlans.com/images/products/8908.jpg)