Criteria for folder w/ thumbstud as stop pin?

[Chiro75]

I want to design (note I didn't say make, yet. Gotta produce one normal folder that works, first) a folder where the thumbstud doubles as the stop pin in the open and closed position. Frame of the folder would be 0.09" titanium (6Al/4V). Are there special criteria for about what diameter the thumbstud should be to be strong enough, as well as the material it should be made out of?

 

[L6steel]

Steve, I would think ti would be a good material and a sufficient diameter to allow for a big enough screw that you won't have to worry about it shearing off. On my folders I use 2-56 screws on the thumb stud but on one where the stud was acting as the stop pin too I think I'd I'd rather go with a 4-40 screw. You'd be suprised how easy the screws shear off.
Hmm, that gave me an idea, maybe you should use a collared thumb stuf that sits into a recess in each side of the blade.Been so long I don't even recall the name of the bit you use to drill the recess.
That way if the operator was into blade flipping you'd be covered.
Just some babbling.
Why you having so much trouble with folders anyway, don't have the right gear??
If you don't have one, you should buy of build yourself a slow turning horizontal disc sander for flat sanding stuff. Best thing there is next to a surface grinder for getting and keeping things flat, Plus, since it runs slow you can shine things up pretty easy with the finer grits. Just need to find a geared motor.
Ugh I type too much.

 

[skinny_dan]

Interesting concept, how about something like the axis lock where the thumbstud also acts as the stop pin, and it moves inside the blade.......and it would only need a simple coil spring rather than the omega springs, but it might be more complicated to make the housing for the spring.

The way I'm seeing it, it would act as a safety on the knife to prevent it from opening as well.

I'm just taking a guess, but the axis lock uses a small steel (is it steel ?) bar which is about 4mm in diameter from what I remember, and that seems to work fine.

 

[Chiro75]

L6, I have a thumbstud I ordered from Knifekits that is a small screw (probably 2-56) but it has a little "shelf" on it that fits a 0.120" holes, I think (actually the same size as through-drilling with a #1 combo bit, I found out in a pinch!). It looks like Darrel Ralph uses his universal thumbstud, which is designed about the same way as far as I can tell, on some of his folders, but maybe I'm missing something.

L6, my folder problems are multifaceted:
1) I make mistakes (sometimes I ream incorrectly, etc).
2) Some of my tooling is worn out (worn out 3/16" ream makes a VERY tight fit)
3) I tend to try to take the easy way out (unclamping the two halves of the scales when drilling and reaming instead of leaving them clamped together. Also not a good way to make matching holes!).
4) I have trouble tapping perfectly straight holes (problem that will be solved when I get a tapper from Higgins soon).

But, each one is a little better than the previous one. I made an ALMOST functional one this weekend. I could probably bash it together, and that's the goal, but I think if I can order some more tooling and get some things squared away (maybe clean my workshop?) that I'll be able to manage it.

Oh, and whoever recommended ceramic belts for Titanium, and slow belt speeds, were right on! What a difference!