nvrtd.design Blog

After separating the tilt servo and ESC channels using the S-Bus decoder, I checked the head speeds again with my tachometer and got the two rotors spinning at nearly the same rate.  I figured it was time for a flight test. TL;DR version:  It didn't go well. There is still quite a bit of instability present.  There are so many things that could be adding to the problems:  Cheap jittery servos, the stability and configuration of the S8R receiver, control forces beyond what the control servos can handle, slop in the system, etc.  After these few test hops, the left tilt servo has been damaged.  I'll need to pull it apart to see if it's repairable.  Regardless, it's a $50 servo that I really didn't need to be replacing.  The right rotor plates are broken, but those are easily printed again. This is the really frustrating part, and I think I need to put this project down for a while and go fly something else to reset my mind.

I had to take a pause on the initial flight tests for a few weeks while we had a new above ground pool installed and then built a deck to match it with the existing deck and house. During a couple of spool-up tests on the V-22, I noticed a strong yaw tendency on the model.  The yaw movement quickly turns into an out-of-control spin before I shut down the craft for safety.  I've tried correcting it with control inputs, but they're not reactive enough.  I have checked the control servos many times and verified they are working properly, so my next suspect is the rotor speeds themselves.  It is possible that one of the rotors is not spinning at the same rate as the other and inducing a yaw motion. The ESCs that I am using are the stock Kylin-branded 40A ESCs that came with the donor helicopters.  Because I purchased the helicopters a year apart, I am not surprised that they are not exactly the same.  The capacitors and heat sinks on one are larger than t...