Spikes on X ACC only

[SuperSharpShooter]

I've just gotten the Hexa back in the air after spending 2 months (!) to finally get a prop balancer that wasn't way out of balance itself. I notice in position hold, that it will rock in the front to back direction by a couple of metres pretty constantly. When I look at the logs, they look fairly clean, except for the ACC X log, which is quite noisy.

What would normally cause this sort of noise? Prop off centre? None of the props seem to have any lateral play around the hub when they're put onto the motor shafts. I spent a very long time balancing the props and hubs and am confident they're well balanced. I find it weird the vibration is only showing up on one axis.

[Max]

[SuperSharpShooter]

The balancer that has worked the best so far is the top flite. It's still not perfect unfortunately. One of the cones is very slightly off centre, so I get a slightly different balance result depending on the rotation of the cone on the shaft. I ended up going through two sets of Du-bro balancers, and out of 4 cones, 3 of them were drilled way (way!) off centre. They are sending me some new shafts and cones at least, but we will see if the replacements are balanced.

I'll look at redoing the FC mount when I get a chance, and maybe redo the calibso and calculations again since this frame's been through about 10 different layouts since it was last done. I'm currently running APC 12x6E props, but have some of the new APC 12x4.5MRs on the way that will probably replace them.

Cheers

[SuperSharpShooter]

Finally solved my vibration problems (hopefully for good this time). I mounted the FC/GPS on a large fibreglass plate, which weighs 150g all up, with four small (~1cm) squares of soft latex foam at the corners. The foam is quite soft but not to the point of letting the platform wobble around.

Before w/hard mounted FC: (copter tried to fly away during the noisy patch at the end)


After: (the z-acc spike is due to a full throttle burst)