I've gotten so much help from the HAMB I figured I should give back what little I can. I needed to cut the bag cups I'm using for my '57 Ford project, not having a bandsaw, and no lathe, and me not wanting to pay someone to cut them down I whipped up this jig for under $10, and I'll be using it more on future projects and can use this for cutting my own bag cups. I used my plasma cutter but this can be used with a torch as well. These pictures were when I did the first one, I added a locking collar on the back of the bolt so I didn't have to push in on the cup while I was turning it. I used what I think was called "Oiler Bushings" they had a flat base on them, then used a scrap drop for the base, a piece of scrap flat stock for mounting the bushings too, then I had a round drop laying around that was the same size as the bag cup mount, transferred the bolt holes to the drop and welded nuts to it. Squared up the drop to the bolt head and welded it on, making sure while I was welding it I got it to stay as square as I could. I made sure everything was welded as square as I could to each other but making the shaft as square to the plate as you can is the most crucial or else you'll end up with a really wavy cut. I marked the center on the side of the plasma tip so I could line it up with my cut line. Things I want to do to this jig before I use it on a next project or things I would do different: 1. Don't use a bolt. A shaft or piece of tubing would be easier to square up, then I would use a locking collar to sandwich the bushings. I started with the bolt out of what I had on hand. 2. I'm going to make it so the plate I clamp my torch to has a bolt to pivot on the jig. Less clutter for clamps. 3. I'm going to make gear reduction crank on the end so I can't turn it too fast. 4. I'm going to wire up a switch so the torch is completely hands free so less chance of me bumping it.
1/2"? That's really short, you'd have to open the top of the cup open so the airline fitting could pass through.
The Jalopy Journal
