Curves

They say that to mark a curve, use a batten. They don't say you need 15 hands.

With a batten held in a curve by a peice of twine, you must shorten the twine until it curves the batten to the correct length. This proves difficult. How do you shorten the twine and tie it off at exactly the right length.

I used course twine and twisted a pen into it. Now I can set the curve by simply pulling the twine further up the pen. I can slide the loop of twine up the pen away from the batten, and this curves the batten a little more.

It gives me very fine control over the curve in the batten.

If the pen is in the middle of the batten, then the curve will be symmetric. If I need the curve to be asymmetric, then I move the pen nearer one end than the other. The curve will be more pronounced at the end where the pen is.

Then I just clamp it in place and draw the line.

All with just two hands.