new bed for MH - Darren?

I have a new mattress that I want to install in the motorhome to use as a sofa and guest bed. I checked out Darren's RV remodel project.

As I recall, the hinge for the top is away from the wall by a distance that equals the thickness of the mattress. And the hinge is a piano hinge, and there are gas struts to get to the under storage. Please confirm.

Also, would you do the struts again? How did you size them?

You are correct, the hinge was mounted away from the wall 8" (the thickness of the mattress, so adjust accordingly). You could go further out, but with the mattresses my friend bought it would not have mattered. He order ones that had reinforcement added on the edges to make them stand up better for sitting on the edge, so they did not flex at all.

I ordered the "BLK-Small" kit (see below), using the distance chart on their site. They were 90# gas springs (each), so they were close to being too strong with just the mattress and platform (1/2" baltic birch), but add covers and pillows they were about right. I would do them again, I think they worked out well and my friend was happy with them.

http://www.hatchlift.com/index.php?route=product/product&path=60&product_id=60

Any cross supports under the ½" BB ply?

Yes, but just glued and stapled to the bottom of the plywood the pieces were not joined to one another to make up a frame. The framing pieces were 1/2" baltic birch too... (see middle pic)

http://familywoodworking.org/forums/showthread.php?33428-RV-Update&p=411189#post411189

Mostly done to build up the edge where the piano hinge was to give the screws something to bite into, but did add some support. Most frames I've seen in RV's are just 2"x3" frames with 1/4" ply on them, so mine was probably overkill.

Looks like one side is differently supported than the other. I see the 'battens' in one picture and dividers in the storage space in another. My concern is that the 1/2ply might need support that goes to the floor to keep it from bending under the tush of a robust person when either sitting on it or sleeping on it. Thoughts? I really want to keep the storage space a open as possible. I could put slats from front to back that are removable. I have a digital keyboard and guitar case that nee a 'long' home.

The one that is more open does have a metal frame under the base, probably wasn't needed, but just used what was in place to get it to span over the tanks and heater. I stood/walked around on that side without any deflection or soft spots, and I'm not a small guy, so if you did a sub-frame under the ply it should hold fine. For the front frame of the storage area, I'd say do at least a 3/4 Ply to the floor, maybe a sub frame to beef it up, but should hold a lot of weight without any deflection if braced to something on each end, either walls or side cabinets.