Heavy Vibration in my Gremlin

[Gryf]

Hi -

I've been test-flying my newly-built Gremlin, and WOW does it vibrate... to the point that airframe buzzes during flight, the video feed to my goggles is shaky and blurry, and I think it's messing with the flight controller too, even after I've isolated the FC with a couple extra layers of foam tape. I've replaced my props with the extra set that came with the kit, and nothing changed. If I run up the throttles while holding the Gremlin, you can even see harmonic vibrations in the props. If I run it up with the props removed, it seems pretty smooth. But with the props, it's pretty extreme. And yes, the prop screws are placed opposite each other, not adjacent... ;-)

I haven't really crashed heavily yet, just some minor bounces. Any ideas?

Thanks in advance,

Gryf

 

[PsyBorg]

Pics n vids would help but I would make sure no wires or the camera is bouncing on the frame. or that an antenna is too long and floppy. these are super sensitive to the slightest tap on the frames. Found that on my first build when the aio was vibrating on the frame before I figured it out.

 

[Gryf]

Thanks, PsyBorg. I'll see if I can come up with more info.

Gryf

 

[Gryf]

I got a short video a while ago out in the back yard... here you can see all the jello caused by the vibration. Again, this is with a fresh set of props. And again, there was enough vibration to cause a buzz from the airframe.

Just FYI, i've isolated the FC with a small block of soft foam.

Gryf

 

[PsyBorg]

The soft foam may be the problem mate. Try two layers of double sided tape. One layer will form to the not so flat surface of the FC and the other will actually be what pads the FC as the soft mounting.

 

[Gryf]

Well, I just added the soft foam yesterday. I had a couple layers of 3M tape before that, and the vibration was such that I added the foam as an experiment. Something's still not right, IMHO.

Gryf

 

[PsyBorg]

Try upping pitch P. That looks like the predominant wobbly axis. Btw what pids are you running?

 

[Gryf]

Here are my PIDs for the Gremlin... essentially, the defaults in Betaflight.

Thanks,

Gryf

 

[PsyBorg]

Here is the ones I last flew on and made my last three vids with. Keep in mind mine is probably heavier then yours and flown on 3s. Keep an eye on temps if you try them specially if you are flying 3s. Like 10 second flights max at first before feeling the motors.

 

[Gryf]

Thanks! I'll experiment around and see what happens.

Gryf