I'm trying APM2 on HK 450pro heli. I just did the test and the result, pitch and roll are alright, it was stable. The problem is with my yaw/rudder. I need to push my rudder to most right to make sure heli stays and basically I had no yaw authority.
I'm attaching the parameter file and the log file. Hopefully I can get a hint on which parameter I need to modify to get a better yaw authority.
Today my heli crashed again from testing the attitude hold and the only part that was damaged was the umbrella gear set at the front torque tube assembly again. This time I used some cheap clone HK brand and it is just not as smooth as the align one. Since I got quite a few bags of them, I used it any way.
Then I tested it by just hovering. It had quite a bit of vibration at the tail and it also randomly twitched. I think it was like how you described yours. I lowered the Yaw Rate P to 1.9 and lowered the Yaw Rate I a tiny bit to get rid of the vibration. Then the tail wasn't holding still so I increased the Yaw Stab P to 2.5 and it took care of it. However, the random twitching was still there.
So I took the heli apart again and put in my last set of authentic Align umbrella gear and it's all smooth again. I can increase my Yaw Rate P back up as well. Is your tail belt driven or torque tube?
Belt on my 600. I wonder if that's a partial cause? I've heard belts are less precise than TT?
My 450 is TT, but I was thinking of converting it to belt anyway... Maybe I'll wait. I put a 500 size tail fin on it so that should cut down on tail blade strikes. I have about 1" clearance.
I have both belt and TT 450s. The belt one is my crash dummy. I practice auto on it. You can land it how ever you want and it just keep on ticking. On the other hand, the belt just doesn't have the crisp response of the TT.
Now the TT! Sigh... Like I said, buy a dozen of the umbrella gear set when you are tuning the heli for APM. You'll need it. :D
Yeah, I've got one set of HK gears, but I'll probably buy more of the Align parts instead of stocking up on HK's.
I'm about half done assembling the heli. So far it quite good. Better finish on the parts than my HK600.