Protech ZOOM 425 ccpm Spécifications télécharger pdf (Page 173)

28.1.4. How fast will a helicopter go?

This question is often asked by R/C car people, and is similar to asking "How fast does a

skateboard go?". A high-end skateboard is designed for doing tricks, not for speed. Similarly, a

high-end helicopter is designed for fast flip/roll rates for aerobatics, not for high cruising speed.

28.1.5. What is the best helicopter?

This question is too broad to be meaningful, and is similar to asking: What is the best car? If

you ask 10 different people this question, you will receive 10 different answers. A more specific

question makes more sense, such as "What is the best aerobatic helicopter between 1kg and

2kg?"

28.1.6. Which helicopter should I buy?

See Chapter 3, First Helicopter Selection Guide

28.1.7. Should I buy an ARF helicopter?

No. When you crash a helicopter, you will need to disassemble the helicopter to replace the

damaged parts. If you built the helicopter, then you will know how to disassemble it. Also, you

will gain much knowledge about helicopters by building one.

28.1.8. How does an R/C helicopter fly inverted?

A fixed pitch helicopter cannot fly inverted except momentarily, such as at the top of a loop.

A collective pitch helicopter can change the pitch of the main blades. With positive pitch, the air

is pushed down relative to the helicopter. With negative pitch, the air is pushed up relative to

the helicopter. So to fly inverted, a collective pitch helicopter uses negative pitch on the main

rotor blades.

28.1.9. Why does a CP helicopter handle wind better than an FP heli-

copter?

When an R/C helicopter flies in wind, it tends to bob up and down due to varying amounts of

translational lift.

An FP helicopter controls the altitude by increasing and decreasing the main rotor RPM to gen-

erate more or less lift. The main rotor has some inertia, so there is some control lag between

when the RPM changes are commanded and when the change actually occurs. Also, an FP

helicopter loses cyclic control authority when the main rotor blades are at a lower RPM be-

cause the flybar paddles are spinning slower.

A CP helicopter in idle-up mode maintains a constant main rotor RPM and changes the

amount of lift by varying the main blade pitch. The main blade pitch change occurs much faster

than rotating the main rotor blades faster/slower, so there is less control lag. Also, since a CP

helicopter in idle-up mode maintains constant main rotor RPM, it does not lose cyclic control

authority when decreasing the main rotor blade pitch to generate less lift.

28.2. Transmitters

28.2.1. What is the difference between an airplane transmitter and a

helicopter transmitter?

Frequently Asked Questions

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Protech ZOOM 425 ccpm Spécifications Page 173