Throttle Problem

[Phreddy]

I bought a used 450 3D. I would like to know if the issue is the helicopter, or the way I have it setup in my DX6 transmitter. Here is what happens:

It binds properly to the DX6. All the servo/swashplate movements are correct according to the manual. With THROTTLE HOLD turned ON, the rotors do not move. I have the throttle at minimum and the throttle trim at neutral. As soon as I switch the THROTTLE HOLD to OFF, both rotors start turning.

I also tried setting the throttle trim very low. Then switching off the throttle hold, the rotors did not spool up. When raising the throttle stick slightly, they spool up, but returning the throttle back down does not stop the rotors.

(For safety, I have the skids clamped to the table and keep my distance as I don't know what to expect). Any ideas on this problem?

[Thomas.Heiss]

Hi,

can you post your 3+1 throttle curves?

What flight mode are you in? N/FM0 or St1/Fm1 or St2/Fm2?

If there's no swashplate movement (with Hold activated) how do your collective pitch curve look like?

B4503D:
Swash down is positive collective pitch up

Is the Ccpm mixer and +- numbers correctly set up?

[Thomas.Heiss]

Oh, I read again and better understand.

Your probably in StuntMode which means there's no 0% throttle programmed.

In that flight mode it's normal that releasing Hold (Off) will immediately spool the heli up.

You need to be at mid stick where 0 degree collective pitch is setup.

It's fixed throttle or V-curve.
Motor always runs, lower range of the stick (mid to bottom) is negative collective pitch for 3D maneuvers and inverted flying.

Depending on throttle curve programming you may have 0 throttle at the bottom dash when flight mode side switch is at Normal/FM0.
This is usually suggested in some, not all, Blade manuals.

If the lowest point is 0% (0..100 scale) or -100% throttle (motor off) on a -100..0..+100 scale then it hardly makes sense to apply a full negative pitch curve with 0-25-50[-75-100] as this gives max -11° collective.

If you want that Normal mode which hardly can be used for hovering as throttle will go up and down all the same, make sure to set up a max -3° to -4° collective pitch curve.

Example for a N collective pitch curve:

30-40-50-75-100

not

0-25-50-75-100

It's best to train with fixed throttle on a Simulator and getting used to collective pitch stick and negative pitch control.

Tl;Dr

Neutral throttle trim is right.
Spool up probably means you're not in N/FM0 flight mode.
Also check your throttle curve for mid point and two bottom points when 0% throttle is applied or not.

Servo travel adjust shall be Normal for CH1/THR and default is 100% for two channel values.