Hand Plane
I want a hand plane. I want to try making one.
The cutting edge would be a cheap, disposable razor. The construction is 4 pieces; the base, front handle (knob) back handle (like a hand saw) and the razor mount. The razor mount is the tricky bit. I need to be able to easily change out the razor and adjust the position.
The angle of attack should also be adjustable.
Razor Blades
The box-cutter blade is tapered out and doesn't have any holes, so it will have to be held in place with friction. There are two grooves, I can have those rest against two small nails, but that whole mechanism will also need to be finely adjustable (to guarantee the blade is perfectly level). So the blade mounts into a small clip with two nails, and a screw to tighten it. That mounts onto the block, with a bolt to adjust the angle. The block attaches to the base with a bolt to adjust the height.
Plane Blade
Blades for hand planes are pretty cheap, around $5. It would probably make more sense to build a hand plane around one of these.