Here's a little flip disc I modeled off the King Kutter one that I built over the winter. I think the disc's and disc hanger assembly came off a Simplicity setup I bought locally from Craigslist. Got the wheels from Harbor Junk. Think I've got maybe $100 into it total. I put some 1" pipe bungs in the frame so I can fill the disc up with about 7 gallons of water for added weight if I need it. Havent had a chance to try it out yet, been raining like a dirty pig so far this Spring.
Nice disk! I am planning on building one from a brinly disk and a moving dolly.
Remove the top section of the dolly until there is one cross brace left to attach the drawbar to the frame of the dolly. Fold the flat plate down onto the frame (90 degrees to the top of standing vertical) and tack weld into place. Using the plate, bolt the disk to the flat plate over the wheels. Then add a front weight from a big tractor between the wheels to add weight to increase the cutting effect.
This should make a good disk.