Bad pinion rocks Frankenheli

I have replaced the tail shaft in Franky and took her to the garage for a test hover. The shaft was bent in a couple of places, along the mid shaft and near the tip. Weird.

What is curious to me is that I never had a severe vibration before. I re-checked, everything is balanced. The vibration is diminished but not entirely absent when blades off, and only happens at a certain RPM range, not above or below. I was turning the main gear by hand when I noticed an excessive amount of backlash, such that the main gear teeth nearly came of the pinion. Or should I say, its the other way around. Turns out the pinion is drilled off center... Curious I never noticed it before... neither the vibration nor the mis-drilled pinion. I suspect this is the cause of the vibration.

Off center drilled...

I also am becoming skeptical of these $10 HK mini-MEMS gyros. This one doesn't seem to hold the head. now; it did seem to before when I first fired up Franky. Maybe its the excess vibration from the bad pinion that sets it off a bit. I will start with a new pinion (damned if the one I have is barely too small for the motor shaft). If the gyro doesn't hold, I will likely try a Spartan Quark on her, but I don't feel like buying one just yet.

So, still no flyable helis.