A working folding knife model for instruction
I needed a working folding knife model for instructions to kids how it works, what you can and can't do with it, etc. without handing them a real knife.
I could not find a free decent working one, so i designed it myself. I figured i'd make a tanto blade of it, just because i think it looks good.
Downloads
I made STL's for different prints: Use the ones marked with (1) to have the least amount of support and height of the prints. All pins in these are printed separate. Use the items marked with (2) to print the
pins 'in place', attached to the blade and left plate.
The left plate marked with (3) is ment for using bolts (see below the list).
You can ofcourse just not print the pins at all and replace them with 4mm bolts that are 18mm length, preferably with sunken heads. If you use sunken heads, 18mm is the length including the head.
Printing and processing
Printing the model should be pretty straightforward. Print it in as flat as possible with the least amount of support. No dimension is all that critical.
After printing some fit and finish is in order to make it working nice, the acuracy of each printer varries in one way or another, so some parts have to be sanded a little.
If using option (3), then drill out the holes in the lock and block to 4mm.
If using option (1) or (2), then make sure that the holes in the blade and lock are big enough so it can rotate, but not too large so the whole thing wobbles. Some sandpaper to sand down the pins patiently will work fine.
Before fitting the right plate in place (with or without glue), first sand down the sides of the blade itself, so it's just slightly less tall than the block and lock. This will ensure the blade rotating freely. Do not make it too thin, it will wobble too much from side to side when that happens.
After sanding down the blade, fit it with a pin to the left plate and put in the lock and block. Now, sand or file down the left pin of the lock so it fits snug but not binding in the hole of the blade in the open position.
If using option (1) make sure that the pins fit tight in the plates and block so they keep things together. You could use a little bit of glue, making sure not to glue the lock and blade.
Last apply some paint if you want before final assembly.
You should end up with a folding knife safe for kids to use, which resembles and works like a lot of folding knifes in the market.
I do hope this model helps teaching knife safety and offers a bit of safe fun to learn!
You are free to use this model as a base of your own, perhaps embellishing the plates, etc. Let me know if you do, it's always nice to see what people do with it.
