I think the pins aren’t ‘pinning’ specific points on the wood strips to specific locations, but just prevent the strip of wood from becoming a straight-lined st

I think the pins aren’t ‘pinning’ specific points on the wood strips to specific locations, but just prevent the strip of wood from becoming a straight-lined strip of wood. The tendency of the strip of wood to straighten itself would provide enough force to make the wood slide along the pins to find the minimum energy solution. (Edit: https://en.wikipedia.org/wiki/Flat_spline https://en.wikipedia.org/wiki/Flat_spline seems to confirm that)