Chapter 28. Frequently Asked Questions

Table of Contents

28.1. General questions
28.2. Transmitters
28.3. Helicopter parts selection
28.4. Gyros
28.5. Helicopter setup

28.1. General questions

28.1.1. How much does it cost?

A typical cost breakdown for a minimum beginner setup is:

Table 28.1. Beginners setup cost breakdown

ItemCost ($)
Transmitter200
Helicopter kit200
Receiver60
Servos80
Brushed ESC50
Brushed motor50
Gyro120
2x batteries70
Battery charger100
Total940

This estimate is based on:Futaba 7c or Hitec Eclipse 7 transmitter, Corona barebones helicopter kit, Hitec Electron 6 receiver, Hitec HS-85MG servos for swashplate Hitec HS-81 servo for tail, Castle Creations Fusion 7 ESC, Kyosho Atomic Force or equivalent brushed motor, Futaba GY240 or GY401 gyro, 2 packs of 7 cell Sanyo CP2400, Great Planes Triton battery charger

Prices will vary greatly depending on your local region.

It is possible to buy an ARF microheli for as little as $150, but as with most things in life, the quality of the items you receive will be proportional to however much you pay.

The Romans did not have R/C helicopters but they understood the principle perfectly: caveat emptor.

28.1.2. How high will an R/C helicopter fly?

A R/C helicopter does not balance by itself, and must be balanced by radio control. When you can't see the R/C helicopter anymore, it will fall from the sky because it can no longer be balanced. Therefore, the maximum altitude of an R/C helicopter is limited by the visual acuity of the person flying it.

28.1.3. How long will an R/C helicopter fly?

This depends on the battery and motor. Aerobatic models will typically fly from 5 to 10 minutes, but models which are configured for duration flight can fly up to 30 minutes. The unofficial world record for an electric R/C helicopter flight is 1 hour and 48 minutes.

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 helicopter?

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 generate 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 because 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.