I've been asked by my better half to do a full length lid on our window seat. It would be 2400mm long and 580mm deep, 18mm baltic birch plywood which the provider says would weigh approx 22kg. Checking on http://theplywood.com/weight says it would be 16kg so quite a range.
I'm trying to figure out what kind of hinge/openers would assist with opening it so it could be done 1-handed, but also be able to hold it open and provide a soft close. I'm guessing some form of piston as that's what I've seen on car bonnets (hoods). I'm assuming that the length of the lid would cause an issue as a hinge at either end might not be enough. It may be that this is a terrible idea and I should go back to researching split cushions that would make her happy.