A sure sign of a project that's gotten out of control is when you start having to build tools just to make parts of the project. Worse yet, when you have to build tools, then build stands for those tools... That's what has happened here.
Originially, I had planned to make the roof with flat pieces of sheet metal welded at the seams. But, as usually happens, my plans change and I came up with a design that required bends with large radii along the sides. To accomplish this, I first had to build a bender capable of bending over 48" of 18 ga sheet metal in one shot. Using an old piece of pipe, some leftover angle iron from the cab, and leftover tubing to make a stand, I builf a bender/roll former.
In an attempt to style the roof a little, I bought 4 John Deere hazard lights, the same curvy ones used on 3000-9000 series tractor cabs. These, combined with the big radius bend on the roof, plus a corner profile cut created in Pro/E to match the lights, created a roof that sort of looks professional...
To cut the corners, a template was printed out from Pro/E about 3/16" smaller than the actual profile required. This was then glued to some 1/4" plywood and cutout on the bandsaw. This template was clamped to the corners of the roof blank. The nibbler was then run along the curved template to cut the sheet metal. the 3/16" is the offset between the cutting bit and the edge of the guide on the nibbler.
Once the corners were cut, the two sides were bent using the bender and some clamps to help the bender along. 48" or so of cold rolled steel is a lot to ask of a homemade bender, but it did a pretty good job, getting the sides rolled down close enough to 90 degrees that they can be pulled square when welding together the rest of the roof...
And of course, the lights make the thing purty...
