Hi,
How should be calibrated the collective and cyclic range for correct autonomous flight ?
For my flybarless gyro like mikado I usually use +/-8 deg for cyclic and -12/12deg for collective
What king of cyclic and collective range should be set at for correct behavior ?
If I use all available collective travel I have -22/+22 deg
For cyclic it's +12/-12
I think that it's too much for the gains to work correctly. Note that this setup work correctly with flybarless setup for 3D helicopter. It's a native flybarless helicopter Gaui X7
My servo arms lever are 18mm if I shorten them to 10mm it would bring angles values to almost the correct angles for cyclic and collective. Is this the way to go ?
Thanks
Replies
Hi,
Have you found what was causing more vibration on the y-axis ? I am experiencing the same problem and I have no clue to what could be the cause. I tought that the tail props where not balanced but they where. If it was related to vibrations from the main rotor, I would expect it to show about the same on the x and y axis.
Thanks
From what I have seen, it's totally normal to have 2-4X as much vibration in the Y axis than the X axis. I believe it is the main rotor imbalance or blade tracking. Since the moment of inertia is much greater in pitch than it is in roll, the force from the blade disk is equal in both axes, but since the roll axis is "lighter", it results in higher actual vibration levels.
That looks pretty decent, especially if it's your first build. Good work. The only thing that concerns me are those spikes, but I assume that is during spool-up and down?
The Y could maybe be a little lower, but it's not too bad.
Hi,
I think the units are 1/10 G in Mission Planner. Just for the sake of discussion I join a graph of vibration I get with that Trex450 Plus I am building.
I believe it is quite good for a first time heli build. I built a couple of quads in the past, but it is my first 450 heli, and to tell the thruth, I like it more than quads.
5 and 20... which units?
I'm typically shooting for less than 1-2 m/s/s in Y axis, x axis is even lower.
That makes sense. Then what would be the acceptable range for the y axis ? I have less than 5 on the x-axis, so is it acceptable to have around 20 on the y ? It seems high to me.
Hi Michel, I'm not sure there is one correct answer to this question. But here's what I think:
There is no reason why +12/-12° would be too much collective for the the collective control program to work properly. Arducopter does not have any pre-set limitations that try to dumb things down like other controllers, so you can set it up however you like. If you have more total collective, then you just need a smaller gain number. If you have less total collective, then you will need a higher gain number. It's a very simple linear relationship.
I do in fact set my helis up for +12/-12 on collective. I used to use +/-10, but in some instances this was less than I needed. I don't actually measure the cyclic angle, I just kinda wing it. But basically, if your helicopter manual has recommendations for a "sport" setup, then I would go with that.
It is true however, that the servo arm length should be as short as possible while still giving you the desired swashplate movement. This will result in the servo mechanism being more precise. All servos have a certain amount of deadband and backlash, which leads to slop in the controls. The shorter the servo arms are, the less slop you'll get.