Cal-5 vibration problems...white powder around tank

[blue_collar2]

My caliber-5 seems to be having some vibration problems. At first the tail boom was vibrating and the linkages were wearing quickly for the rudder control. I set up a dampening system (kinda like the rubber mounting for servos) and the tail boom is better. However, now I'm finding white powder around the main fuel tank (especially on the side opposite the header tank). It's almost like the vibrations in the tail had to go somewhere else...I didn't think it was suppose to work that way.

Anyway, I'm concerned that the frame is eating into the fuel tank...any thoughts or suggestions would be welcome...

[kiwiflyer]

Take the fuel tank out and sand the sharp edges off the frame. Something is out of balance if your tail boom is vibrating. The stock tail blades are not well balanced. Out of 3 sets i have , only 1 set is close to balanced. Is the vibration high speed or low, vertical or horizontal?

[blue_collar2]

Thanks for the response!

I'll recheck the tail blades, maybe they got dinged. I'm using carbon fiber ones that I balanced initially.

The vibration is very high frequency...more of a buzzing. You can't see it, just feel it before the clutch engages. I've checked the obvious things...engine and muffler mounts are tight, and really no change if engine is richer or leaner. I haven't tried a new glow plug...maybe I'll change this weekend.

[kiwiflyer]

high frequency vibe suggests its engine related . you may need to check fan/clutch/flywheel balance. if the heli is relatively new, don't get too concerned until the engine is run in. that buzzing sound you hear now and again could be the rudder control rod vibrating in its guides. just rotate the guides slightly to apply a little pressure to the rod.

[blue_collar2]

Thanks for your response! I rebalanced the fan and clutch last weekend, but haven't had a chance to try it yet.

[shesha]

Your vibration can also be related to a badly tuned engine, your running os50 hyper I presume, if your are, try to get her 2 stroking cleanly for a bit and see if it helps, otherwise you might have a premature back bearing failure, notice any ringing noises ?

Check your MR blades, TR blades and all shafts if you dug her in previously, also one more thing, on one of my cal5's the fan was a little warped caused somewhat of a vibration, double check that, you can bed it back into shape using a hair dryer.

[blue_collar2]

Thanks for the thougths...I'll keep at it and post if I'm still having problems. :noteworthy

Thanks again.