Weta,

Balsa skinned full foam cores are extremely strong under uniformly distributed pressure. You can skin a full (no cutouts) foam core wing with 1/32” (very thin) balsa and with the aid of a few strategically located strips of CF or FG between core and skin, you can have a bullet proof wing. The same goes for fuselage decks.

However, if you remove core material leaving “bridges” in the skins, the ability of the composite to distribute pressure drops drastically. And of course, any non distributed load or highly focused pressure point (e.g., a knife blade) will also slice right through the composite.

In short, so long as your foam core decks are adequately supported in a cradle when applying pressure on the model while inverted, they will also be bullet proof. A full composite bond is of course key in the ability of the composite to distribute forces - whether it be in flight on a wing or on a deck when starting an engine (which actually doesn’t require a super strong deck as is evident by the much weaker sheeted former structure).

David

I don't know how far you're willing to deviate from the original, but Steve Helms' Checkmate was basically a Joker copy.

I picked up a '90' size pattern plane @ Estate sale. Just the plane no info or anything. Plane was unfinished, damaged & obviously an old plane.
Looked good. Had OS 90 Surpass. 72" w.s. 76" fuselage. Thought I could get it in the air for a pattern practice plane while building my other Pattern planes. Plane had problems. I spent almost 6 weeks FULL TIME restoring/ repairing/ improving this plane. It's similar to the Joker & other planes of that era. Do any of you recognize this plane??? Here are 2 photos when purchased. Others result of 6 weeks hard work, much modification. Thanks

It can't be a Joker with out retracts or a nose gear.

Originally Posted by dhal22

It can't be a Joker with out retracts or a nose gear.

?? Matt's original Jokers didn't have a nose gear, they had retracts on the mains and used the MK tailwheel assembly

My bad. Thought nose gear.

She is a beauty, Did you ever find what it was?