ORIGINAL: pvogel
ORIGINAL: doxilia
ORIGINAL: pvogel
The griffin is a modern pattern plane, all composite.
Peter+
Peter,
how does an all composite modern pattern plane crack at the edge of the wing tube?
There must have been severe weakening going on in the foam core (I assume wings were foam) or the design of the framed up wing must have had some issues.
Always interesting to see how models
come apart in flight. When they touch terra firma in abrupt ways, well, that's all together different.
David
See attached picture...
Peter+
David, where the wing tube ends it creates a stress riser. This means that most wing flex is going to concentrate the load to this small section. The fix would be to add a CF spar cap out farhter then the tube so that it would spread the load out. This is one of the things I don't care too much about the current trend in pattern. The airplanes are getting bigger ( The fuse on most current designs are the same size as most 30% to 33% aerobats ) but the weight limit remains. IMO this means fragile airplanes. Not in it's self a big issue except that pattern judges want to see lightning fast snaps. At least the ones that judged the last contest I flew did. Seems to me it all adds up to a recipe for disaster. Not to derail the topic, if we think this merits a thread maybe we could start one.