Time to make up a die to form the roof repair panel on the Lennox. First to make a profile template.....
A sample piece of 19 ga is run through and test fit alongside the "model" car.....
It's real close, but I want to tweak the dies to see if I can get it a little closer
The first sample you had a tendency to flatten out as you progressed to the end, rather than maintain the same radius thoughout. Per the guys at metalmeet I needed to chamfer/radius the coming in and going out of the dies, and by passing it in and out at a slight angle, it would remedy that.
I ran a piece through and "levered down" on the panel as suggested. This does seem to help in carrying the pattern more consistently throughout the length. Then I tightened up the setting just a bit more....................................and judging by the metal waving at me along the top edge, and the marks on the dies, I have some more relief work to do as it looks like the wrong side is tight........(actually planished the top edge and stretched it)
That upper part on the roof is the side that should be shrunk slightly, so I'll give these dies another whirl. I adjusted their shape and set them up in the machine and checked them with feeler gauges, still needed more taken out. Once more was enough, and I polished out the surfaces a little better this time using a scotchbrite pad on the grinder.
The repair panel came out much better this time.....