I have just finished building my HK 450 GT Pro. It is VERY difficult to hover!
How unstable are helis supposed to be without stability software?
The micro twin rotor cheepies seem so stable compared to the Cyclic 400 size.
Should a well setup heli be able to hover on trim alone?
I was hoping to get a good datum before installing the APM but may just install the APM to save wear and tear. I really didn't want the APM project to fail due to a bad heli setup.
Are there any good sites on how to really setup a heli?
Replies
Maybe. But in my opinion it's better to avoid training gears if possible. I never used one and quiet everybody I know didn't use it too. The way the heli reacts has nothing to do with the situation without a training gear. You will avoid a crash but the learning effect isn't there so much. Better some sim sessions instead.
Use always metal gear servos. Even the forcen in flight can strip a plastic gear servo. There are enough cheap gyros that work well. The 20$ HK gyros are quiet good and will do the job.
Don't fly on a hard ground. On some soft grass i ideal. A good setup can hover for a couple of seconds alone, but at leat at 1-2m of height. A ccpm heli is really sensitive and direct so it will start to drift just if it feels a small air or so.
Always start the tail facing to you. Then train hovering in front of you at 1-2m altitude a couple of days trying to keep the heli in position. You will se that your fingers need to make small movements all the time. You won't notice this after a while and it will became an automatism like learning to ride a bike. After that you ca start to move sideways... but google a bit around. There are a huge amount of sites that explain that.
I think this can help: http://www.rcheliwiki.com/CCPM_setup
It's not really a t-rex, but the rotor head is the same. Note the zero degrees head setup images. You should have this setup with pitch at 50%. If not change ball-link rods lenght till it's ok. Do not trim with radio before the mechanical setup is ok.
Helis are unstable close to the ground due to the ground effect. It's like balacing on a ball. The jump from coaxial to ccpm helis is hard because coax compensate the tilt attempt with the upper rotor that has no direct control.
I had the same problem going from coax to cyclic helis. Maybe your setup is not ready.
Try to set the pitch at 50% and see if all levers, servo arms and so on are 90 degrees each other. Flybar seesaw with mixing arms should be at same level. Blades should have 0 degrees angle an be exacly the same. I got my first great success following this rule. Use EXPO settings on the tx to make the central part of sticks no so sensitive.
And try to go at lest 1m/3ft over the ground (DON'T never ever hover inhouse!).
And yes: You should be able to fly an heli and have good control of it before you install an APM. Before that don't even try it.