[HELP] My first tricopter won't fly!

[TomAttard]

I've tried powering the motors without props, there's much, much less vibration.
Since the first video I've changed the settings on the kk2 to fix the twichyness of the servo, it's a lot more stable now.

Any advice to reduce the vibrations?

 

[Ace2317]

Balance your props and make sure you have the prop nut tight enough. I know balancing props doesn't seem like that big of a deal, but it can cause a ton of vibration. If you're still having issues, try balancing your motors as well.

 

[mr.dencehead]

I watched the video and the only prop/ motor that's spinning the correct way it the left/ the right and the back are screwed up. either the prop is on backwards or the motor is spinning the wrong way. the video shows that the left motor is picking up off the ground, but the right and back are planted firmly on the ground. hope this helps. (to switch the motors to spin the other way, just switch any 2 connectors from the motor to the esc)

 

[TomAttard]

Can anyone confirm they've be unsuccessful getting a tricopter off the ground because the unbalanced props/motors were causing so much vibration that it was unflyable? I know it causes vibration but I think I should still be able to get it off the ground even if it's really shakey.
The problem is I don't have a prop balance so I'd like to try a couple other things before I have to order one and wait for it to arrive.

 

[makattack]

When I first flew my tricopter, I was taking off from a grass surface that somehow resulted in vibrations causing the tail boom to shake badly as I throttled up. Enough that I aborted take off. I moved the tricopter to softer sand and it eliminated that. Now, I make sure I take off quickly when over grass. I also ended up dynamically balancing the props and motors with my phone where I would connect one motor to a servo tester, rest the phone running a vibration meter app onto the flight controller, and run up the motor with the prop mounted while securing the aircraft to the table. I just repositioned the prop on the motor shaft until it had the smallest vibration measured. I did this after balancing the props statically.

This article shows how you can make your own prop balancer:
http://www.flitetest.com/articles/vibrations-and-jello-effect-causes-and-cures

 

[PhenomPilot]

If they are the same 9x5 prop that I use on my plane you would have had to drill/reem out the hole to fit it on the prop adapter. If that is the case, they definitely could be that out of balance. The flight control board is going crazy because they don't handle that amount of vibration well. I would try 9x4.7 props that come with a little ring to fit the shaft size that you are using.
To balance, you can use an app on a phone to test each motor and ad tape to dynamically balance. I would start with the props alone first as they can be way off. I made a quick prop balancer out of old hard drive magnets and a cut down nail until my real one came. Not the most accurate but it got me close enough to fly with.
The tricopter doesn't care which way the motors are spinning, the tail rotor will correct for the drift. As long as the thrust is downward, it will fly.

 

[Ace2317]

And basing this off the pictures, your frame looks to be all metal? If so, it's going to absorb more vibration and spread throughout the copter, rather than like a wood boom soaking it in and not distributing it as much. So more vibration making it to the flight controller confuses it even more.

Are you running the motors up with auto-level or without?

 

[Grahamwho]

Swap the front right and the rear props. That looks to be the issue, that's probably why the left one is turning off, it lifts off enough for the FC to see hey this isn't level and slows the front left down while increasing the front right and probably the back some. The right and back aren't getting off the ground because the props are spinning the wrong way. So swap the front right and back or change the direction the motors are turning.

If you think this isn't the problem confirm that the front right prop is spinning Counter clockwise and the rear prop is spinning clockwise. If it's not, your not gonna fly based on the props you have on those motors.