Spoolup resonance?

[Jomaba4308]

I recently crashed, broke 1 blade & bent spindle and main shafts. I replaced the main blades, main shaft and replaced the spindle with the Lynx dfc head upgrade. Blades were perfectly balanced. I flew a test&tune battery and each time there was a spoolup resonance that wasn't there before the crash. At first I thought it was just tight blades straightening out but when it happened again and again I doubt that's it.

[DCflyer]

DFC head with the Lynx ultra dampeners I assume?

Yea I get a little resonance as well - just a little right as its crossing about 1000rpm or so and goes away very quickly. DFC heads tend to do that. If its smooth in the air I wouldn't worry about it. If its like shaking to the point of almost tipping over before it smooths out then you might need to check over some things.

I also run my blades very tight so that doesn't help, but I like tighter blades. You're using the Halo 360's right? Those are pretty big and heavy so you might get a little more resonance vibes than say someone running SAB 350's.

[Jomaba4308]

You must have seen one of my other posts about now having the Halo 360's. Yes the full Lynx head kit with the Lynx dampers. It's enough vibration to make me a little worried but that could be that it wasn't there before, no it doesn't seem to want to tip over. It is stable once it smooths out. I would loosen the blades a little of I could but it's kinda hard, the Halos are tight to begin with in the Mini P grips and more so in the Lynx grips but that's because they're metal not plastic.

[Jomaba4308]

What else could cause a spoolup resonate vibration? Just to cover all basesn

[dedados]

If you strap a heli to the ground it can happen, too tight blades, too fast spool up and cyclic commands with the heli on the ground.

[dr dremel]

I had resonances during spool up show up when mounting a stiffer landing gear. Sometimes it also helps to start from grass insead of hard surfaces. It can really be anything that can change the interaction between the heli and the ground.