wont lift off

[rotorwhiz]

lots of pitch set it up by the book motor seems to really rev. meaning that as i increase throttle main rotor
really revs up but no lift. with motor not running checking pitch i got 5 degrees at mid stick 10 at high stick
have 2 raptors and 2 hawk pro so i know how to set pitch- throttle curves using futaba 6exh and a futaba t7c. what am i doing wrong?? thanks

[Raptor30_V1]

Hello Rotorwhiz,

First of all, turn-off (inactivate) the function of the knob on your Tx, where throttle-hoover and pitch-hoover can be de-adjusted by use of this know. Don't know, why Tx-MFG activate this function/ knobs as the default setting, as many people do not know about and mistakenly de-adjusting the knob, bird won't hoover anymore at mid-stick (or at your stick-position for hoover) ..

Else a very simple rule applies: X x Y = constant ..

W/o a governor holding headspead, it's the aim to first choose a pitch-curve (the master) and then set-up accordingly the corresponding throttle-curve (the slave). By *corresponding* I mean, that for any stick-position (pitch/ throttle stick) on your Tx, the current pitch-value (X) at its paired throttle-value (Y) must hold the main-rotor-revs at a constant head-speed. So if your pitch-value for hoover is appropriate (+4 to +5 degrees: we are speking positive pitch values) but bird won't lift, the engine and therefore head-revs are simply to low. So increase throttle-point, that corresponds to your pitch-hoover position, until bird lifts off.

If still not the case, I can only think of 3 further issues:

- either your engine's carb needles are not set-up well, so lack of power (very rich, very lean mostly engine dies after a hoover)

- or your carb control-rod to the carb is setup badly (asymmetrical setup) and/ or even the carb doesn't open completely for power .. on a well setup carb-control, when carb a 50' size engine's carb is at the carb's mid-mark (50%) and having around +4.5 and +5 degrees of collective, the bird hoovers .. on a 90' size bird, the carb opening for hoovering at corresponding pitch-value is lower, say 40% to 45% ..

- worn engine or weak engine ..

- you are using an other flight-mode than you think you're in?

The opposite of all this is normally, engine revs very high, but main-rotor doesn't engage, so speaking the clutch-liner beeing worn out (over time or crash-with-cheicken-dance) ..

Don't know if this helps,
Best Regards,

Oliver

P.S: Take a look at your carb control setup. If throttle-stick is at minimum (Tx=0% or Tx=-100%), the carb should be almost closed to, at throttle-mid-stick (Tx=50% or Tx=0%) the carb should by at mid-mark and finally at stick-up carb completely open (Tx=100% or +100%) ..

[phantom1500]

Like Oliver says above.

My first question, does the head speed match the engine speed? You say that the motor is revving but if the clutch slips as load is applied then no lift.

Whats the history of this heli, New/old, whats changed if it's been a flyer?

[rotorwhiz]

new unit just built it set v/r knob to inh no difference motor speed matches head speed
thanks