Drophead Coupe asks: "I'm making a pair of doors for a Morgan Drophead coupe. I have the framing just about
done and will shortly start on the sheetmetal skin.
While I have made doors for roadsters this is my first coupe. Unlike the roadster the door skin has more of
a compound curve. It is very slight but there. I expect no problem with the curve front to back but
getting the center section of the door to bow out top to bottom and front to back has me worried.
My current plan is to use a roller to put in the curve top to bottom and use the frame to hold curve front
to back. Am I on the right track ? Will rolling the metal in both directions put some what of a
compound curve? Please forgive me if this is confusing but it would take several pictures to explain
this and I'm trying to keep it under a thousand words."
Tin Man answers:
Measure the crown in both directions with a straightedge. Slight crown would yield a rise of 1/8" to 3/16".
Wheeling in one direction, with adequate blend (say 1" to 1.5" overlaps on passes) will compound the
panel.
Wheeling in 2 or 3 or 4 directions simply offers better chance for smoothness, but at a danger of
over-wheeling. If you are careful, (or accurate) with pressure and roll-to-wheel contact, then also
careful with your passes (or tracks) you can do all your work in one direction.
Remember to layer your passes, such that short passes make a small high , and longer passes make longer
highs. No matter how the panel looks in midair, its truth is only when it's in place.
NEXT
|
