Emax 2204 vibration

[slipshift]

I have a new Emax 2204 2300kv motor that vibrates above half throttle. The ESC is a 12 amp Sky Power with SBEC from Heads Up RC (as was the motor). This happens on 3s batteries but not 2s, maybe difference in speed. It runs smoothly up to half throttle then shakes when I go past. This is without prop or prop nut. When I notified Heads UP they told me to make sure it was mounted flat and secure to the firewall, which it was. Still have the problem and haven't heard any further from Heads Up. Any suggestions for a fix? It hasn't been flown, no crashes.

Thanks,

Jim

 

[French]

Can you try to run it up with a prop on it? Motors generally are expecting some load on them. You generally don't want to run a motor for long without a prop on it.

 

[makattack]

I'm wondering if this is sort of the "natural resonance" at that throttle point. I have a whole lot of motors and prop combinations that all have a certain point in the throttle range where the resonance is bad, but are smooth at all other points... sort of just a bad combination of factors at that one point.

Are you testing this without props? I suppose even an unpropped motor will still have a natural frequency at some point that makes it not smooth.

 

[slipshift]

French nailed it. Runs smooth with prop on. When first checking the motor I got rid of the variables such as prop and prop nut and it vibrated at high speeds. Next, I tried the same thing with an 1806 I had laying around, same result, rough running over half throttle without a prop and smooth with a prop.

Thanks,

Jim

 

[French]

Glad you figured it out!