A008

DESIGN: SynchroLite ~ Power Train (for 2 engines)

Outside Helicopter

Ultrasport:		254	331
	Engine	Hirth 2703	Hirth 2706
	Max. horsepower	55 hp at 6200 rpm. (This is at 103.3%)	65 hp at 6200 rpm. (This is at 103.3%)
	Max. torque	49 ft-lbs at 5600 rpm (This is at 93.33%)	56 ft-lbs at 5700 rpm (This is at 95.0%)

Engine Speeds:

100%	100%	6000 rpm
Upper red line	114%	6840 rpm
Upper yellow range	106% to 114%	6360 to 6840 rpm
Green range	95% to 106%	5700 to 6360 rpm
Lower red range	90% to 95%	5400 to 5700 rpm
Lower yellow range	75% to 90%	4500 to 5400 rpm

Drive Train & Rotor:

Main transmission ratio: 12 : 1 (or 11.8 : 1)?

Rotor Speeds:

100%	100%	500 rpm
Upper red line	120%	600 rpm
Yellow range	112% to 120%	560 to 600 rpm
Green range	95% to 112%	475 to 560 rpm
Yellow range	90% to 95%	450 to 475 rpm
Lower red line	90%	450 rpm
Yellow range	75% to 90%	375 to 450 rpm

Tolerances:

All machined components are machined to a tolerance of 0.0001".

Light Helicopter w/ Two Engines:

Italian Helicopter

SynchroLite

Engine:

Make:	Hirth F-33	Zanzottera MZ-34 **	Hirth w/ tuned exhaust
Maximum horsepower:	25 hp at 6000 rpm	26 to 27.7 hp at 6250 rpm	30 hp at 6200 rpm
Maximum torque:	23 ft-lbs at 4800 rpm	23.87 ft-lbs at 5000 rpm	26 ft-lbs at 5700 (estimate)
100%	5250 rpm	5480 rpm	5900 rpm (estimate)
Horsepower at 100%	22.5 at 5250 rpm	24 at 5480 rpm	?? @ 5900 rpm (estimate)
Torque at 100%	22.5 at 5250 rpm	23 at 5480 rpm	?? @ 5900 rpm (estimate)
Green range 95% to 106%	4990 to 5570 rpm	5210 to 5810 rpm
Drive Train & Rotor:
Transmission ratio:	8.74 : 1	9.11 : 1	9.8 : 1 (estimate)
Rotor Speed: (100%)	600	600	600 (estimate)
Green range 95% to 112%	570 to 672 rpm	570 to 672 rpm	570 to 672 rpm (estimate)

Zanzottera MZ-34i has 31 HP @ 6450 RPM with tuned exhaust.

Note:- Maximum torque will be over a narrower rpm range with tuned exhaust.

Fuel injected engine for Sailplane (MZ-35i) with same specifications as MZ-34 & MZ-34i but different dimensioning.

Engine Induced Rotational Acceleration and Deceleration:

The firing of the engine's cylinder(s) will result in rotational acceleration and deceleration. Engines with fewer firings per revolution of the crankshaft, in other words fewer cylinders and 4-stroke vs. 2-stroke, will result in greater acceleration and deceleration. This 'jarring' must be isolated from the power train. Attaching a flywheel to the engine would help but this will add unnecessary weight and not reduce the shock on the engine's components. It appears that the best arraignment is one of placing a device with spring and damper between the engine and the power train. The Rotax 912 incorporates this into the integral gearbox.

Two alternative ides for the SynchroLite are:

Locate a spring & damper device in the driven pulley, or
Locate a spring & damper device in the mechanism that resists the rotation of the ring gears.

Same Page ~ Different Craft: ~ SynchroLite (w/ 1 engine) ~ Dragonfly ~ UniCopter

Last Revised: February 4, 2005