I was having the wobble / shakes pretty bad on my 130X. When I first replaced the o-rings with the spare grommets, that took care of it. But now, after around 100 flights, it came back and it was consistent throughout almost the entire flight. So here's the steps I tried without
Here's what worked!
- Ensure both parts of swash are connected and tight
- Added mcpx dampeners to swash instead of grommets. First try swash to grips, then try replacing existing grommets with them.
- Check main shaft is true. Take off blades and watch head button.
- Check for cracked main shaft
- Blade balancing. Perfectly balanced - using yellow high performance blades
- Try bullet blades. Shakes were less dramatic but just as frequent
- Ensure even blade grip tension
- Try different blade grip tensions
- Ensure the main gear is pressed firmly in place
- Ensure all servo gears are perfectly in place
- Ensure all servo motors are mounted correctly. Tail servo motor came loose and screw had stripped the plastic cage for it. I used some CA around the screw to mount it firmly back in place. Still no help for shakes but saved me from a future crash.
- 3 different battery packs with different discharge rates, capacity and weight.
- Decrease gain all the way on all 3 axis: (-10 each). Got rid of about 30% of it. Still flies well.
- Remove blades and spool up looking for erratic servo movement. I saw a little and thought I might have to replace the 'aileron' servo, but I didn't. That would have been the last resort.
- Unplugged main motor and looked for same erratic servo movement and there was none.
....... Lube bearings & shafts. Who would have thought?
- Grease on the main shaft around swash
- Grease on the tail shaft around slider
- Oil swash bearings
- Oil main & tail grip bearings
- Oil Bearings behind B & C gear
- Oil bearings around main shaft
- Oil on top of servo shafts
That resolved most of the wobble. It only does it 2 or 3 times per flight now and it's very minor.
That's it! I hope that saves someone some time and aggravation.