Specifications
crystal? ................................................................................................ 163
28.2.11. Why are channel 20 and/or channel 21 not recommended for use or
banned at my flying field? ...................................................................... 163
28.2.12. Can I use brand X servos with brand Y receivers? ..................... 163
28.2.13. When should I move from an FP helicopter to a CP helicopter? .. 163
28.3. Helicopter parts selection ...................................................................... 164
28.3.1. Do my servos need to be of identical type for eCCPM? ................ 164
28.3.2. How does the Castle Creations Phoenix ESC governor mode work? 164
28.4. Gyros .................................................................................................. 164
28.4.1. Can I hover without a gyro? ........................................................ 164
28.4.2. Is a heading hold gyro worth the cost? ........................................ 164
28.4.3. If I put a gyro on each swashplate servo, will the heli hover by itself?
............................................................................................................. 164
28.5. Helicopter setup ................................................................................... 164
28.5.1. How do I set the collective pitch of the main blades? .................... 164
29. Helicopter Myths ............................................................................................. 165
29.1. Expo is bad because it slows cyclic response ......................................... 165
29.2. Heading hold gyros are bad .................................................................. 165
29.3. Shorter flybar increases cyclic response ................................................ 165
29.4. Rate gyros do not need revo mixing ....................................................... 165
30. Technical Appendix ......................................................................................... 166
30.1. How helicopters work ............................................................................ 166
30.1.1. From the user to the transmitter .................................................. 166
30.1.2. Inside the transmitter ................................................................. 167
30.1.3. From the transmitter to the lower swashplate ............................... 167
30.1.4. From the upper swashplate to the rotor head ............................... 169
30.1.5. The rotorhead ............................................................................ 171
30.1.6. Basic helicopter aerodynamics ................................................... 171
30.1.7. How gyros work ......................................................................... 172
30.1.8. GY-series gyro technical info ...................................................... 175
30.1.9. Yaw-rate gyro technical info ....................................................... 178
30.1.10. How ESCs work ....................................................................... 179
30.1.11. How batteries work .................................................................. 181
30.1.12. How motors work ..................................................................... 181
30.2. Motor selection guide ............................................................................ 186
30.2.1. Electrical characteristics ............................................................. 186
30.2.2. Physical characteristics .............................................................. 187
30.2.3. Other characteristics .................................................................. 189
30.3. Motor selection table ............................................................................ 190
30.4. Pinion selection guide ........................................................................... 199
30.4.1. Pitch to module conversion ........................................................ 199
30.4.2. Common pitch equivalents ......................................................... 199
30.4.3. Shaft sizes ................................................................................ 200
30.4.4. Pinion notes .............................................................................. 200
30.5. Pinion selection tables .......................................................................... 201
30.6. Servo selection guide ........................................................................... 204
30.6.1. Electrical characteristics ............................................................. 204
30.6.2. Physical characteristics .............................................................. 205
30.7. Electronics modification guide ............................................................... 206
30.7.1. Adding a brushless motor to a brushed 3-in-1 controller ............... 206
30.7.2. Adding a heading hold gyro to a brushed 3-in-1 controller ............ 207
30.7.3. Brushed tail motor to brushless conversion ................................. 207
30.8. Battery info .......................................................................................... 207
30.8.1. Battery terminology primer ......................................................... 207
30.8.2. Battery pack series/parallel rating ............................................... 207
30.8.3. Battery capacity rating ............................................................... 208
30.8.4. Internal resistance/discharge rate ............................................... 208
The Electric Helicopter Beginner's Guide
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