A laminate underlay plane?

With the structural work complete on my daughter's house (actually its ours!) extension she elected to have the entire ground floor covered in laminate.
This required a considerable amount of underlay to be put down. To give an even level floor throughout one room needed 5 mm foam 'boards' in addition to the normal 5 mm vapour barrier stuff on top.
The foam is similar to Depron but softer, lighter and rather more flexible as well as being only 5 mm instead of 6 and is a rather lurid green!
I suspect it is similar to the stuff that HK have started selling.
With a considerable quantity of off cuts available I just had to make something!
A simple 'test' wing.

Quick to make using just 3 pieces of foam (no ribs) it relies on the relatively thick skin to hold its fairly accurate Clark Y section. It has a span of 500 mm and represents one half of a wing.
It has a balsa leading and trailing edge to give some protection to the rather soft foam. It weighs 29.2 g.
Not really intended to be flown but simply to find out what the material is like to work with.

Without any reinforcement it does have limited strength but such a relatively thick section 'rib less' wing does rather cry out for something to be put inside it - batteries maybe?

For no particular reason other than I had a bit of time spare waiting for some bits I made the other half and joined them together to make a complete 40" wing.

A 1 mm balsa strip has been "inlaid" into the foam top and bottom (exactly above the web) to make a full depth balsa/foam/balsa spar covering the inner 1/3 of the span where the bending loads are highest. In fact the balsa strip is tapered to zero thickness at each end to avoid the stress raiser!
The ends of the wing are simply capped with foam.

The rest of plane? I don't know - maybe!

Went a bit further with this and added ailerons.

Each aileron is simply cut out. the leading edge chamfered with a tape top hinge.

The servo is simply inserted into a hole cut into the lower surface and sits on a foam pad to keep it flush with the wing lower surface.

The wing's rib-less construction means it is no problem to feed the servo wire down through the wing.
With two 3.9g micro servos the wing weighs 2.7 oz (76g) but can support 18 oz (510g) at its centre when supported by its tips.

The ailerons have quite a strong differential action. As the servos use a Y lead this has been achieved mechanically.


And I still don't know what this wing is going to be used on!

The underlay wing has been painted.

Keeping to my "No new planes rule" it will be used an alternative wing for this.

The underlay wing has virtually the same area but is 18% lighter despite being made of foam that is nearly twice as thick.

A short video of the 'Underlay Wing' maiden.

Pretty turbulent so nothing very spectacular.
More to the point the wing didn't break!