Is weight an important factor in F3C ?

tgxtrf · 07-18-2011, 04:43 PM

Well, the title says it all. Is weight an important factor in F3C ?

A 90 sized heli with fuselage can get to over 11 to 14 lbs easy. Beside proper CoG and balancing, do need to make extra effort to reduce weight?

P.S. There is a maximum weight limit in International F3C competition.

Jay

ErichF · 07-19-2011, 07:12 PM

Weight can be a benefit in hovering, but then it can bite you in the end during autos. So, it's a double edged sword.

1DavidH · 07-25-2011, 10:04 AM

This should answer all your questions about FAI/F3C.
http://www.fai.org/aeromodelling/sys...copters_11.pdf

5.4.3. GENERAL CHARACTERISTICS

a) AREA: The swept area of the lifting rotor cannot exceed 250dm

2. For helicopters with multiple rotors
whose rotor shafts are more than one rotor diameter apart the total swept area of both rotors cannot
exceed 250dm2. For helicopters with multiple rotors whose rotor shafts are less than one rotor
diameter apart the swept area of both rotors (counting the area of superposition only once) cannot
exceed 250dm2. The tail rotor must be driven by the main rotor and must not be driven by a separate
engine/motor.
b) WEIGHT: The weight of the model aircraft (with fuel / with batteries) must not exceed 6.5 kg.
c) MOTOR: Maximum piston engine displacement: 15 cm3 2-cycle, 20 cm3 4-cycle, 25 cm3 gasoline only.
Electric motors are limited to a maximum no load voltage of 51 volts for the propulsion circuit.
d) GYROS: The use of automatic stabilisation devices that utilise external references is forbidden. The
use of pre-programmed flight manoeuvres is forbidden. The use of an electronic rate sensor is limited
to rotation about the yaw axis.

e) ROTOR BLADES: All-metal main or tail rotor blades are prohibited.

6.5 kilogram = 14.33, lbs

250dm2 swept area is 80 inch rotor span if I remember correctly.

07-18-2011, 04:43 PM	#1
tgxtrf Registered Users Join Date: Mar 2009 Location: Canada	Is weight an important factor in F3C ? Well, the title says it all. Is weight an important factor in F3C ? A 90 sized heli with fuselage can get to over 11 to 14 lbs easy. Beside proper CoG and balancing, do need to make extra effort to reduce weight? P.S. There is a maximum weight limit in International F3C competition. Jay

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07-19-2011, 07:12 PM	#2
ErichF Registered Users My HF Map location Join Date: Nov 2004 Location: Gainesville, FL 32606	Weight can be a benefit in hovering, but then it can bite you in the end during autos. So, it's a double edged sword.

07-25-2011, 10:04 AM	#3
1DavidH Registered User Join Date: Jan 2010 Location: Birmingham,AL	This should answer all your questions about FAI/F3C. http://www.fai.org/aeromodelling/sys...copters_11.pdf 5.4.3. GENERAL CHARACTERISTICS a) AREA: The swept area of the lifting rotor cannot exceed 250dm 2. For helicopters with multiple rotors whose rotor shafts are more than one rotor diameter apart the total swept area of both rotors cannot exceed 250dm2. For helicopters with multiple rotors whose rotor shafts are less than one rotor diameter apart the swept area of both rotors (counting the area of superposition only once) cannot exceed 250dm2. The tail rotor must be driven by the main rotor and must not be driven by a separate engine/motor. b) WEIGHT: The weight of the model aircraft (with fuel / with batteries) must not exceed 6.5 kg. c) MOTOR: Maximum piston engine displacement: 15 cm3 2-cycle, 20 cm3 4-cycle, 25 cm3 gasoline only. Electric motors are limited to a maximum no load voltage of 51 volts for the propulsion circuit. d) GYROS: The use of automatic stabilisation devices that utilise external references is forbidden. The use of pre-programmed flight manoeuvres is forbidden. The use of an electronic rate sensor is limited to rotation about the yaw axis. e) ROTOR BLADES: All-metal main or tail rotor blades are prohibited. 6.5 kilogram = 14.33, lbs 250dm2 swept area is 80 inch rotor span if I remember correctly.