Hi,

I don't see why you can't change it over to a carbon sandwich panel.  A cored panel like that is the most efficient way of doing things in terms of stiffness to weight.  We have a 6mm foam cored panel that might work for your needs. High Strength Carbon Fibre Foam Core Panel 6mm  The panel has a foam core and does have a similar sort of stiffness to typical plywood of similar thickness so i would expect the flexibility to be similar.  My only concern would be long term durability depending on how much it routinely flexes, shock loading etc.  However there is no easy way of finding that out without testing it.  You could cut it into slats, but the sheet would from a structural perspective work more efficiently as a single piece.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

I built race car seats with only two plies of carbon no sandwich if its secured along the perimeter that's all it needs , not only much lighter than plywood but you can mold it to your butt


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Disclaimer opinions of others will vary depending on what they are selling

Thankyou for both replies both are appreciated. Initially I might try the carbon sandwich as it's the simpler option. I could buy a sheet the same dimensions as my current plywood seat pan and if after trying it I feel it's too stiff then I could always try cutting it into say 2" or 3" slats and space them out to give the desired stiffness/flexibility. 

Anything over 2mm thick is deemed structural and for your application i would go down the route warren has suggested with a cored panel. If you can find a local water jet cutter and give them the material and a template they should be able to help you out

A fine jigsaw blade will cut the foam core panel very easily.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Thankyou for the replies. Sorry I'm late replying but I've been in hospital. I will get on an order the panel Warren recommends