Laying out an irregular shape

[mla2ofus]

One little trick I was taught is to exactly duplicate any flat irregular shape. Chalk a straight line from top to bottom, then chalk another straight line at a right angle to the first. They don't have to be exactly centered with the shape.consider one as "X" axis and the other as "Y" axis. By measuring where each corner or change of angle along the edge of shape is in relation to each axis as long as each measurement is made square with the axis it is measured from , you can lay out this shape on another piece of plate,wood or whatever. Hope I described this well enough. I'm sure it's common knowledge to a lot of you, but it's come in handy over the years with lots of different materials.
Mike

[lotechman]

I have never done it myself but read about how boat builders in years gone by would take the lines off a boat using two sticks. The idea was to stand one stick vertical beside the blocked vessel then touch the intersecting stick to the hull. Each point on the hull would be marked on the sticks by lines and labeled.
One would do this do this at several points down the length of the hull. Later on the hull shape could be duplicated on a loft floor so that frames could be made.
I have used really light strips of flat bar ( 1/8th) and laid them against a shape then tack welded bracing so that the shape would hold and I could take the light frame over to another plate and trace it out.