The Quick Orange Fox

Dennis pivoted the wings on carbon fiber rods, rotated by servos.

Dennis pivoted the wings on carbon fiber rods, rotated by servos.


Many of us fly cheap airplanes, but few fly anything as cheap as the Multiplex Fox.

Looking a bit like a scaled-down Multiplex Easy Star, it’s sold as a $15 glider: no motor, no control surfaces. Throw it hard and high and wait for it to come down.

But it looks so much like a small version of the planes we fly that inevitably people began tinkering with it.

Matt Abrams had the first one I saw. His was blue, a work in progress on the day I saw it at the PCC airfield.

Dennis shows how easily the wing detaches from the fuselage, a crashworthy feature.

Dennis shows how easily the wing detaches from the fuselage, a crashworthy feature.

A week or so later, Mehmet was flying one at Baylands. He was still tinkering with battery location, trying to find the ideal balance point, but his plane flew quickly and quite well.

Mehmet had sliced out elevator and aileron surfaces from the horizontal stabilizer and wing.

He said he bought three and was going to experiment until he came up with the best configuration.

Next came Dennis Castleman, ever the innovator.

Dennis simplified his controls by independently pivoting each wing on a carbon fiber rod, rotating each one with a servo, allowing the wings to serve as both elevator and ailerons. He powered his plane with a 12mm Feigao inrunner motor and a small press-on propeller.

He glued solid carbon fiber rods along the center of gravity of each wing, then mated them to a carbon fiber tube buried in the fuselage.

The wing is slightly rotated, showing its pivoting ability.

The wing is slightly rotated, showing its pivoting ability.


His build was the cleanest I’ve seen so far, and his plane was quick and nimble in the air.

Its only drawback, he found, is that it falls out of the air when he slows it down: it stalls quite easily.

If Dennis, Mehmet and other inventive builders can tame it into slower, more stable flight, this is a good candidate for combat sessions.

Multiplex foam, which they call Elapor, is a bouncy and durable isotope of EPP, perfect for destruction derby flying.

Want to make your own Flying Fox? Here’s a nice step-by-step article and a thread on RC Groups.

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3 Responses to “The Quick Orange Fox”

  1. Dave North says:

    Dennis has really pulled one off there. It flies much better than I thought it would, and not at all as I expected. Fun being so wrong sometimes! The downside turns out to be a nasty tip stall that grabs him every now and then, but the plane is so light that no damage is done when it goes down. Also, the wings just pop off the carbon tubes.

    Overall, a darned interesting effort.

  2. brian says:

    Need to move the CG forward a bit. It should cure the nasty tip stall bit. And it should glide a little better.

    Most free flight planes fly well, until someone try to pilot it!!

    Brian

  3. Dave North says:

    I’m not sure we’ll ever know. Dennis found another lump of foam to play with — a weird UFOish thang with a bulbous front and small span.

    Guy’s obsessed.