Originally Posted by maricard
The higher seat height is 18 inch (under knees).
Do you think that is too height?
It would be in my van, but I'm on a different chassis so I don't know how much headroom your van has. The height from the floor is semi-important, but the height to the roof is more important.
The VW Rock-n-Roll mechanism (which mechanically is very similar to what you've drawn) can facilitate both rearward rake as a seat and a flat bed, but it has a nasty side-effect whereby the bed surface ends up about 4" higher than the seat surface (due to how the hinges sweep through their arc). It looks like yours is similar. This means you eat into the headroom when deploying the bed, or your seated height is very low. On my (very small) van, it would have been very hard to build a rock-n-roll bed that allowed me to sit up in bed! VWs have relatively tall rooflines, so they get away with it by just having the bed be relatively high from the floor. Your van might also, but you'll want to measure carefully.
I suggest taking a bunch of measurements - sit on the floor near a wall or doorframe and have someone measure to the top of your head. This will give you a basic minimum for headroom above a seat/bed.
BTW, Bus Depot here in the USA re-sells the Reimo Rock-N-Roll hinges. If they won't deliver to Canada, drop me a PM, I have a set from them sitting in a box that I didn't want to eat the re-stocking fee on. I'd be willing to sell them for what I paid.