Progress has continued on a steady, if not rapid pace. The 3 day a week workload has increased due to some outside consulting to a much heavier workload in January and February( more like 7 days a week!), which has slowed progress somewhat.

Cowlings have be made for the [...]]]> Vol. 5 Number 4

Winter 2011-2012

Progress has continued on a steady, if not rapid pace. The 3 day a week workload has increased due to some outside consulting to a much heavier workload in January and February( more like 7 days a week!), which has slowed progress somewhat.

Cowlings have be made for the engines, which require careful design since the engines already have fan cooling, but at the rear of the engines. The cowlings have to be made to reverse the airflow into the engine fans when the aircraft moves out of a hover and starts forward. This makes for a complicated design with many complex curvatures to minimize weight.

The cowls are divided into two halves, a front half looking like the front half of a dirigible, and a rear half with a more complex tapering shape. The front halves were made first. The first front cowl was made of long gores cut out of a vinyl polyester foam, then covered with fiberglass.

While durable with good shaping characteristics, the weight was a little heavy, so the second front cowl was made of two layers of 5 oz carbon fiber.

The carbon fiber version is substantially lighter than the fiberglass version. The two “retired” molds are in front.

The fiberglass version at an early stage of fabrication, mounted over the engine.

Providing for access panels, baffling, and engine mount attachment points has greatly complicated the design.

Spring 2012

Work continued on the two engine cowls. By April, both cowls had been made from the male molds, with one cowl more or less complete, and the 2nd one about ½ finished.

First cowl showing large access panel in middle.

Internal baffling for the cowls started in late April

Mating the passenger compartment to the bellmouth.

Design of the structural members to connect the bevel gearbox end of the drivetrain with the passenger compartment is also a complicated task. These structural members also provide aerodynamic counterbalance to the torque from the engine and rotor which cause the aircraft to rotate in reverse to the rotor direction. As a result, these units also have a complex curvature.

Preliminary design of these units is in progress.

2nd engine mount

Progress has accelerated since moving back to a 3 day work week in August. Another, larger model was built and tested in September.

Work on installing and operating one of the Hirth F-30 aircraft engines began in September.

Engine # 1 is depicted below, and ran [...]]]> Vol. 5 Number 3

Progress has accelerated since moving back to a 3 day work week in August. Another, larger model was built and tested in September.

Drive Train Assembly

Work on installing and operating one of the Hirth F-30 aircraft engines began in September.

Engine # 1 is depicted below, and ran for the first time for a few seconds in mid-November, turning the prop depicted in the other photo. The test wiring setup can be easily disconnected for use in startup of the second engine.

The first test run showed some adjustments needed to be made in the location of the engine, which took until mid- December to complete. Work on the 2nd engine’s mount started in mid-December.

Electrical Wiring

Wiring the engine up to a test panel with engine monitoring took a couple of months.

The jumble of wiring depicted in the photo below resulted in a full wiring schematic in AutoCAD, and will be used to create a more organized wiring harness board for the full scale wiring for the jyrodyne to follow.

The black hose in the front was connected to a regular aircraft gasoline tank for the test, with the 2 stroke fuel mixed 50/1 as per Hirth’s instructions.

The engine started on the first try!

Tractor Propeller

A platform had to be constructed to service the installation of the 4 bladed tractor prop, which was completed in November. The belt connecting the prop with the drivetrain may also be seen in the photo.

Next step after engine run

Cowlings will be made for the engines, which require careful design since the engines already have fan cooling, but at the rear of the engines. The cowlings have to be made to reverse the airflow into the engine fans. This makes for a complicated design with many complex curvatures to minimize pressure losses.

After the cowlings are completed, the next step is mating the passenger compartment to the bellmouth and drivetrain.

Design of the structural members to connect the bevel gearbox end of the drivetrain with the passenger compartment is also a complicated task. These structural members also provide aerodynamic counterbalance to the torque from the engine and rotor which cause the aircraft to rotate in reverse to the rotor direction. As a result, these units also have a complex curvature.

Preliminary design of these units is in progress.