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Starwood Development Symposium 2009
Woodside, Calif., October 23-25
We kicked off the symposium with Peter Jakadofsky hand delivering to
Al Wert the 150th turbine sold by Starwood Models. This is a significant milestone for Starwood as we are seeing
an increasing demand for Jakadofsky turbines as customers are now starting to focus on engines with
higher reliability and proven performance over other turbine systems currently available for use in model
helicopters.
In attendance at the symposium were Al Wert, Len Mount, Peter Jakadofsky, Tim Dawson, Tony Bettanini and
Jim Davey. Jim was absent when the group shot was taken, however we found a good photo of him. A
perfect mix of experience, theory, craftsmanship, two machining experts and four master modelers, all
together for three days to exchange ideas and discuss current and future applications for the Jakadofsky
turbine engine in scale and model helicopters.
The Jakadofsky R/C turbine engines have been experiencing a steady power increase, from the RS (first
production release) to the current PRO5000, through changes to the internal components and the software
configuration that control the turbine's operation. Various clutch gear, spur gear and turbine operating
speeds combine to allow for an almost infinite range of head speeds. This makes it easy for the customer
to match a mechanics set to a particular Jakadofsky turbine based on the model's rotor span and desired
main rotor rpm.
One focus of the meeting was the amount of customization that is possible for a turbine project. Our primary
goal for the symposium was simple: fly our prototype J-10 Hiller utilizing a vectored thrust tail system
using the turbine exhaust thrust, a newly installed Starwood mechanics set and the new Starwood Flybarless
rotor head. This goal seemed simple at the start. The J-10's predecessor, the Hiller J-5, was one of the
first full size helicopters to fly without a tail rotor blade system and instead used a forced-air fan to
counteract the torque of the main blades. While the production versions of the Jakadofsky turbine are
designed to mitigate the effects of the exhaust in order to minimize forward propulsion, Mr. Jakadofsky
engineered a special version of the PRO5000 engine with additional exhaust thrust for this project. The
exhaust velocity was increased to help provide more thrust to stabilize the model in this application.
The J-10 uses a servo controlled stainless steel deflector system designed by Len Mount in the tail chamber
at the end of the exhaust system, which regulates the amount of tail thrust. The challenge for Mr. Jakadofsky
was to figure out how much exhaust velocity was needed and change the engine's power conversion ratio to
increase the amount of exhaust thrust. First flights proved that Mr. Jakadofsky's calculations were correct
and there was plenty of gas flow to control the tail.
During our discussion, it was decided that the J-10 needed a shorter main shaft to help reduce any chance of
ground resonance, and that removing the main shaft would delay the much anticipated testing the next morning
at the field. Cutting and redrilling the main shaft usually requires the removal of the shaft from the mechanics
set, but with patience and Tony Bettanini on the cutter and drill press, we were successful in shortening the
main shaft for the new Starwood Flybarless rotor head without first removing it from the model.
After making a new set of pushrods, the new Starwood Flybarless rotor head was installed and it was out to the
flying field for the J-10 Hiller's first flights the next morning. As usual, connecting a laptop to the V-Stabi
outdoors proves to be a challenge with seeing the screen. A quick adhoc towel fixed the problem, but the photos
tend add an air of secrecy about the process. Once the V-Stabi configuration was completed, the settings were
transferred to the V-Stabi control module and the turbine was run up again for the next test flight.
Another interesting problem with the J-10 model is that the center of gravity of this model is well forward.
It has a very short cockpit compared to the rather long tail boom. The wheels sit just forward of the center of
gravity, so most of the model's 35 pounds is on the two front wheels. The rear of the helicopter weighs a mere
five ounces. Take offs were done very carefully! After some initial test hops, it was discovered that that tail
required 80 percent exponential on the tail channel to keep it in position and under control.
We continue to improve the design of both the Top and Bottom-Mount Starwood mechanics sets.
Vario Germany will soon be releasing two dedicated mechanics designed for the Jakadofsky PRO series turbine to
be used in their large new models, further increasing the range of models that will accept these engines.
Another recent development is the introduction of the Jakadofsky PRO-X turbine for use in UAV
models of up to a three meter rotor span. Keep an eye open for new development projects on our web page. We are
looking forward to a prosperous 2010 with more modelers discovering the ease of operation and reliability of
Jakadofsky turbines.
In conclusion, our symposium was a resounding success. The J-10 Hiller was flying very well
for a first outing. The full cockpit will be completed shortly and we should have this model at some of this
year's flying events. Ideas were plentiful for future projects and all were thoroughly discussed and noted for
future development. Everyone had a great time and is looking forward to next year!
Starwood Models bottom mount mechanics installed in the Hiller J-10. Dual Kerosene fuel tanks are installed on
either side of the mechanics and all of the turbine and radio gear is neatly arranged under the cockpit floor
panel.
Len Mount & Jim Davey setting up the V-Stabi flybarless control unit through a laptop computer.
It flies! Test Pilot Jim Davey is at the controls.
Happy building and flying!
Starwood Scale Models
www.starwoodmodels.com
650-851-9027
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