A092

A 092

DESIGN: Dragonfly ~ Weight & Balance

Based on the complete helicopter Dragonfly General Arraignment #1

Outside Helicopters

Robinson R22:

Ultrasport 254 Center of Gravity Limits:

The center of gravity on the Ultrasport 254 must be between 4.5" and 1.5" in front of the mast.

Dragonfly Power Train & Rotor / SynchroLite Fuselage

Rough Comparison of Weights:

Primary Group	Ultrasport 254 Achieved	SynchroLite Allocated	Dragonfly Allocated
Power Train / Rotor / Flight Control
Power Train / Rotor Hub / Flight Control Assy	~	~	100.00 ⁽¹⁾
Power Train - Assembly - Final	39.93	82.00	~
Rotor - Assembly - Final	45.13	42.00	~
Rotor - Blade - Assembly	~	~	28.00 ⁽²⁾
Fuselage / Engine
Fuselage - Assembly - Final	49.63	25.00	30.00
Landing Gear	16.43	6.00	6.00
Tail Rotor	1.68	0.00	0.00
Control - Flight - Assembly - Final	11.85	14.00	6.00 ⁽³⁾
Engine & Exhaust & Tank	81.26	72.00	70.00 ⁽⁴⁾
Miscellaneous	8.05	12.00	13.00
Total	253.96	253.00	253.00

Try for 90 lbs. or less so that more can go into the engine and fuselage. BOM is on 0986.html

This is only the six blades. The other components are included in ' Power Train / Rotor Hub / Flight Control Assy'. The current weight is based on the sum of the SynchroLite's four larger blades (inc. 1-lb tip weight) at 6.25 lbs each, plus 10%.

Swashplates and components above it are included in ' Power Train / Rotor Hub / Flight Control Assy'.

Engine weight and power:

The Zanzottera MZ202 2-cylinder engine at 82 lbs. The Zanzottera MZ301 3-cylinder engine weights 110 lbs. Will be advantageous to add a third cylinder, at approximately 16 lbs. for a more reliable engine.
The Hirth 2-cylinder engines are 68.2 lbs. The Hirth 3-cylinder engines ar 100 lbs. The Hirth 4-cylinder horizontally-opposed engines are 92 lbs.
It would be safer to increase the weight by 24 lbs and use a 4-cylinder horizontally-opposed engine.

Datum:

Origin (0,0,0) is the point midway between the centers of the two rotor hubs.

The reference point of the fuselage is the hole in the center back of the seat. This hole is 6.5" ahead of the Origin.

Weight and Balance:

Full Name:	BOM	Wt. Ea.	Qty.	Length of Arm (in)			Moment (lb-in)
		(lbs.)		X	Y	Z	X	Y	Z
Power Train / Rotor / Flight Control
Power Train - Assembly - Final	1134	55	1	2	0	8	110	0	440
Rotor - Hub - Assembly	1138	18	2	x	x	x	x	0	0
Rotor - Blade - Composite VR-7 -Assy	1209	4.67	6	0	0	0	0	0	0
Control - Flight - Assembly - Final ⁽¹⁾	0451	6	1	0	0	24	0	0	120
Fuselage / Engine
Fuselage - Assembly - Final	0500	30	1	18	0	30	540	0	900
Landing Gear - Rear - Composite Legs	0000	3	2	13	0	72	39	0	216
Control - Flight - Assembly - Final ⁽¹⁾	0451	8	1	-12	0	24	-96	0	144
Control - Power Train - Assembly - Final	0581	8	1	7	0	24	56	0	192
Instrument - Assembly - Final	0375	5	1	-34	0	36	-170	0	180
Electrical - Assembly - Final ⁽⁵⁾	0000	0	0	0	0	24	0	0	0
Engine - Assembly - Final ⁽²⁾ put in assy page	0103	62	1	15	0	xx	930	0	xx
Engine - Assembly - Final ⁽³⁾ put in assy page	0580	23	2	15	0	xx	690	0	xx
Exhaust - Assembly - Final	0597	8	1	12	0	24	96	0	192
Fuel - Assembly - Final	0358	6	1	2	0	42	12	0	252
Empty Weight:		254	⁽⁴⁾	Empty Moment:			1445	0	xx
Weight & Balance - Load - Baggage		34	1	0	0	60	0	0	600
Weight & Balance - Load - Fuel		30	1	-3	0	48	-90	0	1440
Weight & Balance - Load - Oil - in Power		2	2	0	0	5	0	0	10
Weight & Balance - Load - Pilot		230	1	-16	0	40	-3680	0	9200
Load:		296		Load Moment:			-3770	0	xx
Total Weight:		550	⁽⁴⁾	Total Moment:			-2265	0	xx
				CofG from Origins:			-4.1"	0"	xx"
				Symbol:			x_CG	y_CG	z_CG

Red BOMs are those for SynchroLite, and will be replaced.

The flight controls are split between the PT / Rotor Assy and the Fuselage Assy.

Based on the Hirth H-32 engine, w/o exhaust.

Lighter weigh and perhaps safer alternative to single engine.

Safety items, such as rotor governor etc., will be in addition to this. See; OTHER: Miscellaneous Safety ~ Ultralight. Governor = 4 lbs

Assuming that the engine comes equipped with a pull-starter, then the battery (12#) is not necessary. The battery (and 'jumper cables' :) ) can therefor be considered as baggage and not be included in the 254 lbs weight. In addition, the batterey can be relocated , for and aft, for balance.

Dimensions are in inches and weights are in pounds.

Total weight is item quantity times item weight.

Same Page ~ Different Craft: ~ SynchroLite ~ UniCopter

Last Revised: November 22, 2003