Good morning everyone. I have several questions about mechanics on setting up a traditional heli for the APM 2 that is on order. I apologize if this is more brainstorming then well thought out questions but I am trying to get my thoughts down before they flee.
My Project is using a trex450 clone a Turnigy 9x and will be using the APM2 with detached GPS. I am also using the printed GPS mount listed in the wiki and will isolate the APM with Align PU isolation Gel on a mount on top of the tail boom block.
1.Last Night I started the assembly of the air frame that I may use for this build. I am also testing other flight stabilizers and have a Flymentor build also pending. It is possible that the APM may be overkill for some uses but that is a different discussion all together. With only Swash linkages I have centered the servos and leveled the swash to provide 0 pitch at 0 throttle (curve) 50 pitch (curve) gotta love the swash levelers. Lots of trial and error but I figured that a almost perfect mechanical setup will pay back in spades when it comes to setting up the electronics.
2.As with the Flymentor I assume that the APM will require all trims and sub trims set to 0, The Wiki is pretty vague on the electronic setup, except that it is supposed to be set for ACRO or Airplane with no mixing.
3.The Wiki also states that a FBL rotor head should be used but some have said they have good results with a Fly Bar head. What is the difference in performance with the APM. I have a FBL bird and the simpler mechanics are nice but I actually prefer the stability of a Flybar on the rotor disc
4.On the servo setup I may be using a 6 Channel Flysky receiver to shave a few grams off the weight from the 9 channel receiver What should the corresponding servo connections be to the APM. If the traditional heli requires that the motor esc be on channel 7 then cool. I am not going to run a camera off the initial 450 test platform and would really like to shave the weight since I am adding so much weight with the APM Gyro and wiring.
Replies
For #3, I much prefer the flybarless. Malcolm seems to have good results for loiter with a flybar, I found it caused me problems.
For #4, maybe this isn't exactly your question but when it comes to connecting the motor esc, I connect it to my radio channel 7. Robert has put in some code recently to allow the APM to control the throttle but that's only really necessary if you're short on channels or if it's possible you will fly out of radio range (which is very far and probably not legal!).
1) I use zero pitch @ mid stick and a governor which is set at 1600-1700 RPM (any thing over 25% throttle and the head is at 1600RPM) You are correct, a good mechanical set-up will pay dividends.
2) Never use Transmitter trim, i use CH7 on the APM 1 and a free receiver channel to auto trim the heli in flight. Use a heli flight mode on your transmitter. You will find it easier as all the premixing is done for you. Throttle to Pitch etc
3)I have used a flybarred head and it seemed to work. ( i use flybarless all the time now) You will get longer flight times without the flybar and a lot more precise feel.
4)As for your radio i cant tell you which channel on your receiver controls which command. If its the same as futaba then i can help.
I use the APM gyro now will remove my GY401 from the razor.