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Hambonetw
Jun 30, 2009, 10:59 PM
Hi Guys,
not really sure if this is the right place, but anyway here is my latest.

It will be available from the usual suspects in F3J (3.7M span) and F3B (3.1M span)

Here is the website bumf:

SiΣma II
1. The 18th letter in the Greek alphabet (Σ, σ)
2. Maths the symbol Σ, indicating summation

This sailplane like all of my designs was developed over many years, and like its name suggests has been the sum of all I knew with each version.

Beginning in 1985 with the Sigma I prototype that was intended for and proved to be quite successful at MOM pylon racing, this new version comes with a good pedigree that I hope it will continue to bear out.

The aerofoil section used for the wings – JH35 series – has been designed for constantly changing flaps and has been thoroughly tested in a professional wind tunnel. The aerofoil profile is quite different to most that are flying today and is designed to get you up as fast as possible, keep you there as long as possible, but at the same time when reflexed, go as fast as possible.

With its long nose and generous moments the Sigma II gives good lateral response while saving nose weight needed to compensate. Wings are elliptical to provide optimum lift distribution, while the removable tailplanes are designed to give exactly correct compensation with minimum drag penalty.

Other than the more technical aspects, this plane just looks right and that is generally a very good performance indicator.

Available in both F3B and F3J versions (3.1M span and 3.7M respectively) the plane is completely CAD designed and CNC moulded and comes highly finished with a full set of hardware and a large 20mm ID ballast tube installed.

SiΣma II Specifications (F3b & F3j)

Span: 3.1 and 3.7m respectively
Length: 1.63m
Aerofoils: JH35 series, 8%, 7.5%, 7% elliptically blended.
Controls: Ailerons, Elevators, Flaps, Rudder
Wing area:
Weight:
Attached Images
Loooong wings...
Big rudder

Towhook and ballast tube are installed.

Baggies!
Tail half
Yes it comes assembled
Big joiner.
All the baggies

Tom Gressman
Jun 30, 2009, 11:07 PM
What is the wing area and empty weight of the F3J 3.7 m version? Estimated flying weight?

Hambonetw
Jul 01, 2009, 03:28 AM
What is the wing area and empty weight of the F3J 3.7 m version? Estimated flying weight?

Hi Tom - Sigma II F3J empty weight is: Ca 2000 gm or 4.4lbs -

Flying weight depends on your set up.

Wing area is: .752 m2 or 752Cm2 or 8.094461ft2 or 1165.602 In2

Hope it helps.

James Hammond.