Dear all,

following on from my earlier post about veneering foam wings, what are people's thoughts about honeycombing? Is it worth the effort, how much weight would you expect to save, what effect will it have on the strength and stiffness of the wing, what shapes should I cut and how much area should I remove and where in the wing etc. (The questions seem limitless!!)

If anyone has done this, either successfully or not, and has any advice they can give me, I would be most grateful.

Many thanks,

James

Hi James,

do you mean to fully composite build your wings? If that's the case, that is going to be a lot of work! A couple of friends from our club did that (full-composite pattern plane, the [link=http://www.gal.ch/it/galleria/coppaeuropa2004/images/PICT0648.jpg]Swan 3[/link]), but it took them more than 3 years to complete it, and as of today only 1 plane is flying...
Too much work, too much money involved, if you ask me...
Surface quality is of course as good as it can be, the honeycomb structure does not come through and stiffness is great withouth the need of further structure (no formers, just a couple of half-ribs to support the wing tube). You can paint in the moulds for further weight saving. This firends model didn't come out as light as it could possibly be. I still think that with selected foam and balsa you can achieve very good weight and keep costs (!) and effort at an acceptable level.

Regards,
-Fabrizio

No, I don't mean to build composite wings, they will be balsa veneered foam. I mean honeycomb as in removing some foam from the outboard section of the wing panel before veneering, to reduce the weight of the wings (less foam and more importantly, less glue).

James

On modern wings -which are thin airfoils (10% aprox) honeycombing is simply of little/no value.
If you have a clamping setup to properly laminate foam to balsa -then select balsa grade/ grain/ thickness.
a 1 lb virgin foam (this is very important and can make a huge weight difference) pressure bonded with Probond or laminating epoxy will provide the best weight / strength wing you can do .

The foam - laminating agent and wood must all be dust free and even and exactly aligned or voids in surface may occur.
done right - you can not peel wood from foam -anywhere.
also you can barely detect the joint - the lamination will appear to be a fused thing - experiment first with pressure and adhesive - you will see.

Dick,

thanks for this info. My wing is 12% root, 10% tip so I will follow your advice and not honeycomb! It will also make for an easier job...

James

James
I had for 6 years a Python. It is still flying. I made two sets of wings. One honeycombed with retracts, the other not and fixed gear. I found no difference flying either set of wings. Save yourself work and build the plane light
Kiwipaul

would this help?

http://www.geocities.com/CapeCanaver...328/index.html