I think better to spend time building than drawing. I can do that too. I went to engineering school. I can make thousands of beautiful drawings. But this is not productive.http://forum.driveonwood.com/t/spiral-path-heat-exchangers/3657/79
That being said you will need to make ‘layouts’. I have a big roll of brown paper. I use a pencil compass, ruller. I made a pencil/triangle that is very helpful.
Cutting paper is easier than metal 1979 292
Rindert