FINALLY, I was able to take my Funkey 50 Hughes 500D out for it's first test flight! The flight was a mixed bag. It sure looked good in the air, it handled well AND it came down in one piece! On the down side, I had a fairly bad vibration, espeically when I turned the governor on and increased the head speed. Here's the details:
Evo 50 mechanics (flown before install, very smooth)
OS 50 Hyper/Hatori muffler
Head speed on the curves, about 1500 - slight vibration noticable in landing struts and horizontal stabilizer
Head speed on governor - low setting- 1650 vibration Much more pronounced,visible at the same locations
Head speed on governor - hi setting -1750 vibration became violent and shook exhaust tubing off the end of the muffler.
Hover pitch set at abt 6 degrees
Any ideas/suggestions where I should look first? Engine has new bearings, entire air frame was rebuilt before the install and as I said, was test flown and was very smooth.
I would surely check the blades first!
I'm assuming that it's a low pitch vibe being that you can see it well.
After that check the flybar spacing to make sure the paddles are at the same distance from the head and the weight of the paddles are the same.
Hope this helps! :thumbup:
All things being the same except for the added scale fusalage, I think that it is probably a resonance vibration due to change in total mass and location of new mass.
Some weight could be added different places to change resonance freq or find the MR rpm where it does not vibrate and set governor there.
Where the fusalage attaches to mechanics, more flexiable mount attachments could be tried or even more rigid attachments points could be tried. Both methods would change the freq that any resonance would happen.
If 620 mm blades could be fitted and MR rpms limited to lower value it would probably sound more scale like.
You might try to stiffen the MR damping for higher MR rpms or soften damping for lower rpms to see if it is a mast bumping vibration problem.
Those are my best guesses from problem description.
Good ideas. I thought about 620s, might just have to think some more. I will check those areas mentioned and see what happens. It sure looked good in the air!