Originally Posted by
carlgrover
If I was going to build a Goldberg Ultimate from scratch and wanted to ditch the ply I would draw the outline of the fuse on paper then fill everything else in. Maybe copy the basic design of an Aeromaster or something. The wings are already feather light so nothing needed there.
carl
Well for me it's been almost 30 years since I built mine...but the lite ply sides were pretty well hogged out with "lightening holes" if I recall.
OK...weigh all the liteply that comes with the kit then weigh all the balsa that replaces it..
What's the net difference...?
Lite ply is crumbly stuff...especially with a bunch of lightening holes in it and especially after the plane experiences some bumps and bruises.
I was running a "bargain priced" plastic 15 x 6 one day and during a vertical climb the prop exploded and the torque reaction ripped the firewall loose from the fuselge sides. The throttle cable and fuel lines helped keep the engine tied to the plane.. I don't remember the details of the repair..but most likely some fiberglass cloth and epoxy was involved.
What I DO recall during the original build was beefing up the firewall with real aircraft plywood as well as the wing strut mounts.
The mount I used for the OS 1.20 was aluminum..so these were places where the plane started picking up some serious weight.
I did a "mock up" assembly using the plastic mounts that Goldberg supplied and there was just NO WAY I could see ANYONE USING THAT PIECE...
.