Over the winter lockdown I kept redesigning the roof in my head. Because the cabin roof is curved and the top of the windscreen curved (though not the same curve that’d be too simple) it would look weird if the cockpit roof was flat. But if it’s curved you can’t hinge it across the middle without either some very fancy hinges or having horizontal ‘upstands’ across the roof.
Finally I decided I’d stick with a one piece sliding roof, but make it lighter and easier to slide. Rather than heavy GRP I’d use a timber frame and aluminium sheet. And I’d avoid the problems with the sliding rails by having rollers to run on the cabin roof. If it doesn’t work as planned there’s always the option to saw it in half and fit upstands and hinges.
This part is made from a recycled hardwood door. It follows the curve of the cabin roof quite closely and here you see it when I was fitting and adjusting the rollers.