Scratchbuilding pulleys?

[Adam Baker]

Thanks, I'd love to see a picture of what that thing looks like. I may have to get one for myself.

MPWR, can you take pictures of the punches? Im specifically interested in the punching end. Want to know how the end is beveled to great the cut out.

[MPWR]

There's nothing at all fancy about the cutting ends of the punches. It's simply a very clean, sharp 90deg edge.

I think that you may find a punch and die set a bit harder to make than you expect. Both the punches and the die need to be made of hard steel. I'd recommend drill rod for the punches (air hardening if possible), and I'm not sure what I'd use for the die. Also, I suspect that to get good cutting edges on the die, the holes need to be reamed, not just drilled. This is likely why they're so expensive to purchase.

I've tried it, and met with rather limited success. Limited enough that purchasing a set seemed reasonable. Really, it's the kind of machining that I don't particularly enjoy- simple operations on difficult to machine material, as opposed to complicated operations on easy to machine material.

[Adam Baker]

Yea, I could see having to ream the holes for added accuracy.

It was just a thought for an interesting project. Ive got access to several CNC machines in my machining class, so I dont think the machining aspect would be all that difficult.

Dunno if I would do it or not, just something I was thinking of doing, thats all.

Ive also concidered making my own photoetch bending tool, similar to the hold-n-fold & the etchmate. Again, just for a project in class, and to see if I could do it.

[ScaleTuned]

Hi guys, got home late so not many pics but I have some ...

Here is the punch from HL-


Styrene holes fresh out of the punch. Very little sanding is really all thats necessary, I think they came out better than expected.


The aluminum tubing slices cut with power mini miter saw. These look great too. I'm going to use these on my project. Going to cut the "inner" smaller tubing to size, space the sliced tubing "rings" and epoxy in place. The front of the "pulley" will then wear a Mr. Model PE pulley face. When they are done I will post a pic also ...

[torinobradley]

I have had very good results chucking the larger sprue sections in a drill and using files and sandpaper, making the pulleys with that. You can make them in whatever shape you need, then just cut em off and make more. Then, using a few layers of chartpack tape for the belts. I even made the dome style pulleys like on the water pump or flathead motors. Good luck!