Hi:

I was wondering if anyone ws building any older designs in Lost Foam... like, use the foam cores to make ribs and parts in balsa and use the foam cradles to construct the balsa wings in like the C/L Stunt guys do? Makes for very light structures.

Thanks


Bruce

Bruce, I've admired this technique for many years but never used it. The 2 meter guys would honeycomb their foam wings which probably equals the lost foam method in weight and still maintain the strength needed for the demands of R/C aerobatics.

I watched Jim Kirkland build a Beachcomber wing from balsa long ago. He constructed a saddle jig, complete with dihedral, to construct the wing. This was before foam wings were popular. The lost foam method is essentially a saddle jig. Most guys would say that if you're going to the trouble of cutting cores, why bother with the lost foam method? If you use the epoxy carefully to sheet and choose the the wood with even more care, you can build a very light foam core wing. Dick Hansen in Utah used to espose this in his column in Model Builder long ago and he was correct.

But one thing that I'm in total agreement with you is this, light weight airplanes fly better! Wood selection, application of glue, use of sandpaper and attention to detail makes for a superb flying airplane!

Frank

Thanks for your response Frank, I had suspected as much, I liked this special method and enjoy building so I had considered it briefly. However, I think that you are correct, internal foam, current methods, is just one less step and perhaps still the way to go. The Lost Foam Method was popular for CL as the designs were so weight critical till larger engines became more popular. I just needed a little confirmation from someone longer in the pattern busienss to decide if I shuld design this into a plane I'm working up.

I will not use the Lost Foam method but our regular foam core setup or even a traditional built up wing like I have always done.

Cheers

Bruce