The test flight from the other day with zero drift working well on hover does appear to have been a one off. Today, there was drift, and there was to some extent corrective action in place too, but it was too small and too late – I suspect PID tuning as the ‘too late’ action suggest the horizontal velocity PID I-gain is dominant. I think for the moment, I’ll stick with D-gain disabled as the results were still better than previously.
So today I moved on to trying my larger, more powerful blades (11 x 3.7 rather than 10 x 3.3). This should reduce the spin rate for a given power or put it another way, more oomph available for corrective action. What a mistake that was; 2 flights, 2 blades (£25) smashed to pieces, and a significant reduction in the (already limited) drift control.
The only plus side is that it did suggest a cause and fix: with the bigger blades, spin rate was much reduced, perhaps allowing more noise past the DLPF and in to swamp the genuine sensor readings; so on Wednesday (next good forecasted weather), I’ll head down to the park (no walls, no iron railings for dismantling props) with Phoebe reloaded with her 10 x 3.3 props, and a lower (10Hz) DLPF to see the net result.
I simply can’t risk another crash – the 10 x 3.3 blades are rare as hen’s teeth compared to the 11 x 3.7 – perhaps that’s why?