Thread: An idea for a contact grinder.

As promised, video:



The center punch ended up not being hardenable steel, but it still works okay. I'll still probably make another one. Just because.

To make the shaped interior of the receiving die, I originally cut out the shallow hole using an end mill so it'd be nice and flat. I made it a little deeper than it needed to be to cut sheet metal.

Then, once I heat treated the part, I dropped a small blob of solder down in there and chucked up the punch in my drill press. I spun that down into the receiver until it heated up and squished out all the solder that didn't fit, then I punched one piece of steel and ran that in there until it brazed onto the solder.

With that done, I reamed out the center hole again with a drill bit on a pin vise and a needle file. That's responsible for the nicely defined little shoulder on the washers. If I hadn't done that, the cut parts would just be little blobby domes.

Geting parts out is a little more hassle than I'd like it to be, but sitting here I just realized that one way to do it would be to simply punch out a bunch of washers without doing the center hole, then screw the receiver down a little so it doesn't make snug contact, put a washer back in, THEN punch out the center. They shouldn't be stuck, then. In theory.

Still, this is by far the easiest way I've found of quickly making small numbers of washers.

Now to just make a bunch more kinds!