I can't remember how many layers of glass you were planning on using, but with 2 layers of CF (fibers running in opposite directions) I still get a little flex ( and this is with the aluminum cantalever.
The glass skins (or CF skins in your case) on the sides of the rail really don't do much for the load bearing, its the parts that are on top of the rails (and the aluminum under it in your case) that take the loads. Due to the way I wrapped the sides over the rails I've got ~6 plys of skin glass at different orientations along the top of those rails (3 plys from each side wrapped over) however the real load bearing capacity is the fiberglass pultrusions which is the layer right underneath those skin plys. There is ~1/4" of fiberglass there across a 2" wide rail (equivalent build up of about 27plys of the skin glass I'm using if I would have laid something that thick by hand).
Is there a way for you to test this as you go? Might be worth it.
Yup, as I mentioned previously once I get the seems all glassed up so it's all truly held together I plan to load test it to see how it handles the weight and what kid of deflection I get (both from a comfort standpoint and also so I don't hit the top of my truck!). I plan to suspend a platform off the front of the cabover a couple inches above the ground. I'll record the height off the ground and start loading up the weight. I'll be able to see how much the cabover deflects doing this and also if something does happen to fail things would only drop a couple inches which is far safer than weight dropping 3-4'!
Currently due to curiosity I've breifly done a pull up on the front edge of my camper even though the seams aren't all glassed up. Held so far. I noticed the passenger wall that has the short piece flexed inwards a tad though, however as mentioned the seams aren't tapped yet which will counter act that motion and also the eventual internal cabinetry will brace the wall as well. I'll know more after load testing it.
On another note. Man those photos bring back memories. I really like your design and think you are on to something here!
Home skillet
All kinds of sticky/dusty fun!
Yeah I hope I like it when it's all said and done otherwise I'll go mad, haha.
Still digging your actuators? I'll need to order up some units sooner or later here as I shift over to building the upper half.