The angle between the masts on the UniCopter's two Intermeshing rotors is 18º. The UniCopter's Interleaving rotors will probably be parallel HOWEVER the 18º (162º between two x-shafts) is probably ideal for the struts.

A pair of special crown and pinion gear sets could be purchased and used to test both configurations. Note that they must be the same scale and that the Interleaving will be a little special at the junction of the 2 X-shafts at the center of the fuselage.

Is it correct to say that, given a common set of criteria, a heavier (larger) motor will provided a greater power/weight ratio then that of a smaller motor?

The criteria would be that of a modern motor that is brushless, has rare earth magnets and perhaps is an outrunner.

Thanks,

Dave J.

Not sure you can say that.

Some smaller motors could easily have a higher P/W ratio. They can afford to have those exotic magnets. They don't need massive shafts and mechanical structures to transmit the power.

Keith Cress

Many small motors achieve seemingly outrageous power outputs due to their very high rotational speed. Most big machines are limited to 3000 or 3600 rpm, and although higher speeds are possible the physical limitations of the materials the rotor is fabricated from prevent such high speeds being achieved with very large machines.

The reduction is approximately 5:1 to 6:1. A set of spur gears (eventually helical) will be the most efficient and the large one will leave the center of the hub very open.

The motor and the rotor will be rotating in opposite directions. There gyroscopic precessions will partially cancel each other and thereby reduce the forces that are transmited by the spar back to the fuselage.

Total rotor reduction 8:1

UniCopter Full-scale; Final - Bevel Gears, Ratio 3.375:1, 5 DP, 16/54 teeth. Crown has 10.76" pitch diameter.

UniCopter Full-scale; Secondary - Bevel Gears, Assembly, 5 DP, 20/30 teeth. Crown has 6" pitch diameter.