Transferring Offsets

This picture shows the layout of the panels I need to cut. In the last post, I showed how I prepared the long panels: 2 feet wide by 11 feet long (actually, two of them are 9.5 feet long and the other two are 10.5 feet long). Now I need to mark the designed onto the panels so I can cut them.

AVS Hull outputs tables of offsets. You can set how you want the table prepared. I opted to have the offsets printed every 6 inches along their length, and printed to the nearest 1/16 inch. For you metric people, you can choose to print decimals instead of fractions.

Here’s a snippet from the offset table.

The first column is the length along the long edge of the panel (the X coordinate). The second is up from the long edge (the Y coordinate). Notice that all the X coordinates except the first are on 6 inch boundaries. The first coordinate is the coordinate of one of the corners, so it was output at its exact location.

When transferring the offsets to the plywood, I start by drawing lines every 6 inches. I can then measure from the edge of the plywood along the appropriate line to locate the point.

For this to be accurate, you need to make sure the end and edge you use as a reference are both straight and square relative to each other. I made sure to use the factory cut edges of the plywood figuring that they would be more straight and square than the edges I ripped on my table saw.

After marking all the points, I use a straight edge to connect the dots. If I wanted to be more precise, I’d tap small nails into each position marked on the plywood then use a thin piece of word bent along the nails to draw a curve to connect the dots. If I had wanted a more precise shape, but didn’t want to do the nail-and-strip thing, I could have simply printed the offsets at a closer interval (say, every 2 inches). More points mean that the straight lines form a closer approximation to the curve, but at the expense of having to transfer more offsets. For this build, plotting every 6 inches seems to be a reasonable compromise.

Here is a picture showing one of the marked sheets. Next up: Cutting the panels out of the sheets.