RE: Foam core .40 size profile fuse?
David,
It's very doable and I've already got a version of my FF540P done in foam core style like the bigger ones we sell. Not convinced yet on weight but it is definately easier to build. The balsa built up fuse is pretty quick since you can just get away with slapping the CA and lay the sticks as you go. With the foam you have a slightly different approach with different glue for foam and then capping the perimeter. I plan to keep playing around with this idea and maybe introduce the FF again next year in foam version. I've also noticed it's easier to repair after you bust it. Just spread the epoxy or urethane glue into the cracks and clamp it back together. The built up stick and sheet style always has a challenge with all the internal fractures!@#!
Mike