The Saker is the glider I have aimed more towards racing performance than other models I have produced. 3m span for a high performance glider is by no means a revolutionary idea. Each model that I’ve been involved with has taught me a great deal and this new model idea includes some design innovations to make the next step in performance
The effectiveness of a V-tail is highly dependent on the air flowing over it, the fuselage of the Saker is the area where the most obvious innovations can be seen. In order to optimise the air flow over the tail.
The aim of the Saker fuselage was to manage and control the airflow whilst maintaining the mechanical strength of the fuselage. The optimum combination of real world practicality and optimum laminar airflow controlled with the sculpted Air Flow Inducers (AFIs).
The shape of the fuselage still allows for up to 1.5kg of fuselage mounted ballast and the wiring loom to fit easily. An F3F model which can be built without a shoe horn! The tail boom of the fuselage enhances the lateral stability and tracking of the Saker as well as it’s strength in the air, with an oval cross section.
In the air it was immediately obvious that the Saker’s stability is remarkable, with a wonderfully stable platform which simply cuts through any turbulent air and allows the pilot to be thinking about the next turn rather than keeping the model in a straight line.
An easy to fly model can be set up just as you want it and allow you to concentrate on getting what you want out of each flight. The Semi elliptical planform takes some beating for a wing. Many wings have different sections between the root and the tip and the new Saker wing is no different. However, rather than blending different sections and never quite having the section that was intended, with a much shorter transition area the true sections are in place a cross more of the Saker the wing.
As I spend more time setting the Saker up I will add some settings and more notes to this page.
The Wyvern
The Wyvern’s planform follows my design philosophy that an easy to fly model is one that you can fly fast and accurately.
The Wyvern’s wing is a composite of a number of different sections. The wing section has been designed to provide optimal speed performance in both neutral trim and also with a small amount of camber. With the camber, the section increases it's buoyancy without the usual drag penalty. This new section has proved itself ideally suited for high speed turns and allows the Wyvern to carry more weight than many equivalent models.
Under neutral camber the low drag section delivers a highly efficient high speed model.
An indication of just how thin the new wing section is comes when fitting the servos. Although 10mm servos are ideal to drive the flaps, 8mm servos make for a far better option for the ailerons.
The accuracy and consistency of the wings starts with high quality solid aluminium molds.
First winter
I do not believe in using the first customers as beta testers. Being the first to fly a design is a very rare and special moment that helps to motivate me to be out flying in all conditions. I Whilst I might not be the fastest pilot, a winter of my flying and landing means that designs and lay ups are thoroughly stress tested. Throughout the testing I have been struck by the natural pace of the Wyvern. The joiner now has been designed to take ballast, in addition to the same fuselage mounted ballast tube from the Saker. I’ve just never used it, despite flying in 50+mph winds.
My preference has edged towards a CG of 86-90mm- which gives a more rounded turn rather than trying to ‘ping’ the model in the turns, you can do these turns but I’ve chosen not to. The design of the wing section lends itself to the snap flap coming in early as you apply the elevator. My preference is that the 2-3mm of deflection comes in by 50% of the elevator throw and remains constant as more elevator is applied.
The winter weather and my weekend commitments means I’ve not been able to put the Wyvern against the clock yet- I just hope I don’t hold it back too much!
