I got my new VTX in.. I was super excited to get it in the ol Shuriken and put her in the sky. I had to move some components around to squeeze it all in but I got the job done and headed out to the field to try her out. I didn't have a good feeling about it. I probably should have tested it out before hand but I really just wanted to get in the air. I got everything setup and within a couple seconds of the launch the damn thing started having a seizure. It was shaking pretty bad. I flew it around a little, hoping it would clear up, but it didn't. And if that wasn't;t enough I was also getting a low radio signal warning from my Taranis. I knew one of my antennas was a little beat up so that wasn't really a surprise. The shaking on the other hand kind of caught me off guard.
I was kind of confused my first thought was the accelerometer just needed calibrating, but I later recalled the acc didn't have any effect when in acro mode. So I was at a loss. The only thing I could think of was the little soft mounted board labeled IMU, that I moved over to fit my VTX inside the frame. I really wasn't sure what that board did... but I didn't think moving it would be a problem.. I only moved it forward a couple centimeters.
After I got it home, the first thing I did was calibrate the acc. Took it out to test it, but the shakes were still present. So I took the props off to check the motors, and everything spun just as it should. No stuttering or vibrating or anything that would suggest it would have the oscillations that it was. So if it couldn't be the acc, and the ESC's and motors were working properly... it had to be that IMU board. As I noob I had no idea what that thing did. I tried to do some research on it, but everything just said it worked along with the acc to stabilize the quad. So I went ahead and removed the 8 screws to open up the frame and that's when I saw it. The little IMU board had somehow gotten pushed down at an angle. Seeing that made it pretty clear that was probably the problem. Turns out the IMU does work with the acc, but it also works independently to relay information to the motors and flight controller. If I understood correctly. It is the gyro. I knew what I gyro was, but I did not know what an IMU was.. Apparently they are pretty much one and the same.
So... I put some fresh two sided 3m tape on the bottom and replaced the board so that it was nice and level. Replaced the chopped up receiver antenna and put everything back together and took it out for a quick los test. The first thing I noticed was the acc needed calibrating again, I always switch on self level while flying los and the last time I calibrated the acc it was crooked as a politician. So I just popped it into acro mode and then I noticed something else... The shakes were gone! Other than me flying horribly in acro, the shakes were absolutely gone. So just to make sure I took it back inside, re-calibrated the acc, and took it back out to test again. All was golden. Everything was working perfectly. The problem was solved. I was pretty happy.
So my next blog will hopefully be an amazing flight with a perfectly flying quad. This hobby is pretty great. Its fun and full of excitement. Flying is such an out of body experience and a thrill. But one of the things I have learned is even when things go wrong, and they will, solving the problem can be just as fun and exciting as the flying part.
Thanks for reading guys and happy flying!