I've had this disk with a lot of tapped holes in it for quite a while. This is what it looked like after brushing it off. I have a need to bend a bunch of thin diameter wire to repeatable dimensions.
Actually, I've had this project done for a while, I made this at Techshop a few months ago. Anyway, here's how I did it.
First, I started with my disk.
Step 1: Bending Arm
The center of the disk was tapped for 3/8-16, so I used a shoulder bolt for the center axle.
Add a piece of DOM tubing that is bored for a bronze bushing, and clean it up with a nice shoulder.
The shoulder presses in to a piece of 4140 that has a slot cut in it.
Finally, this piece is all assembled with just a quick weld.
Step 2: Guide Blocks
At this point, you have the pivot arm. This needs a block on it that will actually push the wire as you bend it. A couple more chunks of 4140 from my scrap bin. Lay them out with layout fluid, cut away excess metal, drill and counterbore / tap. Then a small disk is cut that spins on a short shoulder bolt.
In the future, the guide blocks will be set up to be pushed for/aft on a spring, should I need to bend a shape that isn't round.
Step 3: Center Shape Mandrel
This is nothing more than a piece of 1 1/4" diameter CRS rod that was cut, drilled and faced.
This serves as a mandrel for the wire to be bent against.
Step 4: Assemble and Use
Now I just have to spend the rest of my life making an assortment of tooling for it.