300 will not take off

[chopperman]

My first flight that lasted literally 2 seconds broke my blades, I replaced them and nothing is bent because they are no vibrations. Got new blades on and didn't touch a thing else and she won't take off. She just sits there at full trottle trying to take off and getting light on the skids. What's the deal?

This is my first heli back after a couple years and I'm new to this fbl thing, am I supposed to see the swash move up and down while in throttle hold when I change the pitch values on my dx7? Because I can hold the stick at 50% and move the middle to 75 and my swash doesn't move, is that right? I just want to fly guys what's the deal?

[Nelsonisms]

Originally Posted by chopperman

My first flight that lasted literally 2 seconds broke my blades, I replaced them and nothing is bent because they are no vibrations. Got new blades on and didn't touch a thing else and she won't take off. She just sits there at full trottle trying to take off and getting light on the skids. What's the deal?

This is my first heli back after a couple years and I'm new to this fbl thing, am I supposed to see the swash move up and down while in throttle hold when I change the pitch values on my dx7? Because I can hold the stick at 50% and move the middle to 75 and my swash doesn't move, is that right? I just want to fly guys what's the deal?

I'm not very familiar with the DX7, but regardless of what happens when you're in the pitch curve menu the pitch should change when you move the throttle stick so long as you've set a linear pitch curve for that mode. So in throttle hold you should be able to move the throttle stick and see the swash move up and down. You should also see the swash tilt with aileron/elevator input. If that is not happening then I'd double check all of your transmitter settings. Are you sure you didn't miss anything in the recommended settings for the DX7?...page 5 of the manual.

[chopperman]

The pitch does change when I move the stick but say if I have the stick at %50 and go into my radio and move the %50 value to say %65 the swash doesn move. Is that right?


My only guess is while the blades are running its not getting enough pitch.

[Kieranar]

I would go over the mechanical setup on the swashplate make sure you have 0deg pitch at mid stick , you should have + 8deg at full throttle and -8 at zero throttle , ensure when your doing this you have linear pitch and throttle curves .

Did you check your feathering shaft after the crash ?

[HamminHelis]

Disconnect the three leads from the esc to the motor, power up your radio and initialize heli as usual. At half-stick on radio blades should be flat...0 degrees pitch. Above that they should go positive up to ~ 11 degrees total. Should hover around 5-6 degrees.

For safety sake it's a good idea to disconnect the motor any time you're working on it while it's on anyways.

I doubt you broke just the main blades if it previously flew and have not changed any TX settings.

[HamminHelis]

Was just thinking...make sure you didn't break one of the Jesus bolts that retains the rotor head or main gear. There is also a shaft collar right above the frame.

It's possible to break the Jesus bolt and still have the bolt head or nut still attached, look closely.

CW rotation...you did install the blades correctly?

[chopperman]

The blades track fine so the feathering shaft is fine. All I did was put a new set of blades on it. I will try and disconnect the motor wires and see what is happening

[chopperman]

Originally Posted by Teeg

Was just thinking...make sure you didn't break one of the Jesus bolts that retains the rotor head or main gear. There is also a shaft collar right above the frame.

It's possible to break the Jesus bolt and still have the bolt head or nut still attached, look closely.

CW rotation...you did install the blades correctly?

Bingo that was it, top Jesus bolt that held the rotor on. Thanks guys for your help I would of never figured that out!

[HamminHelis]

Yea! Same thing happened to me and it took a bit to figure out. You can break the Jesus bolt and still turn the rotor head (the swash driver, aka follower arms) do that.

Good thing you found that; eventually it would have ended...badly.

Tom

[Papa Tom]

Check to make sure your elevator servo is working.

[dsuida]

Originally Posted by Teeg

It's possible to break the Jesus bolt and still have the bolt head or nut still attached, look closely.

This is exactly what happened to me when I had the same issue as you.

[Braydubya]

That top bolt has broken on me 4 times...once mid-flight.

But I do believe it has saved other parts from breaking and bending