Designing folding knives

[D.Crawford]

I've been working on my first folder (a slip joint) and was surprised at the work involved in getting the geometry
of the blade shape, tang and back spring just right. To those of you who make folders, how do you go about your
design & build process? Do you use pencil and paper or CAD software? Do you start from scratch every time or
reuse your templates & alter them for new designs? Do you make prototypes to iron out the bugs?
I'd like to hear your thoughts. Thanks.

 

[Calvin Robinson]

I design mine with pencil and paper then build a prototype or two then make patterns out of steel for future knives.

 

[Frank Niro]

I do the same as Calvin except I use micarta or counter top cover for my hard patterns. I've been making liner locking folders for some time, but I still want the hard pattern to test out fitting, looks and whatever before starting with the materials to be used. Frank

 

[Phil Tham]

Most of the time I draw them out on paper to start with and cut patterns out of whatever inexpensive hard material I have available. For slipjoints, once you have a blade tang geometry that works you can usually apply it to other designs.

 

[Patrickknives]

I have a couple of geometries worked out that I keep a hardend pattern of. I start with paper and make a plastic model and then move on to metal.

 

[kc custom]

Pretty much what everyone else said but-- when I get it right on paper I use woodworkers
glue to glue it to thin mild steel, cut it out and then I can see if its going to work. Once I get
it working well we go to good steel. On the first knife of a pattern once its working well in the
frame I make a pattern of hardened steel.
Ken.

 

[D.Crawford]

Thanks everyone for your input. I feel better now about my trial & error approach to the process.
Was just afraid I was somehow taking the long way 'round the barn.

Thanks again all.

 

[roblockwood]

I use CAD, mostly so I can easily view both the open and closed blade position, and make tweaks to both simultaneously. Makes it easier to get a nice blend on the spine when closed and open, etc..

 

[Stacy E. Apelt - Bladesmith]

An invaluable tool is a "rise and fall" indicator. Also, Ron Lake's book on "How to Make Folding Knives" and Bob Terzoula's book on " The Tactical Folding Knife".

 

[Cubane]

G'day there,

For designing slipjoints I have a process I follow. I do it all on paper but the steps I follow would be similar if I was designing it in CAD. I wrote up a page on my website describing the process I use.. hopefully reading it makes sense.

http://knives.mutantdiscovery.com/slipjoint1.html

I also found this site as a handy reference recently

http://www.knifeknowhow.com/3-blade_folder.htm

It also has a few other helpful pictorials

Alistair

 

[timos-]

I use a CAD a program to design folding knives. For a computer junky like me it is really a blast. Although, I have not actually made any of the folders yet The nice thing is you can print them out to scale on paper, or send em off to a water jetter, etc. Cloud hosting makes losing your patterns and files a non issue (atleast while the western world holds up).