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View Full Version : Throttle curve for quadcopter ??


jamesb72
12-30-2011, 03:34 PM
I have just built my first quad, X copter, with Hobbyking v2 controller with quad v4.7 firmware - it flies really well. I have a question about throttle curve, I am flying with std throttle curve, which means props will stop at bottom stick, I did a motor stop descent yesterday, and powered back up, but realised the gyro's re-initialised 'in the air' so I had to hold a lot of cyclic correction to stay still, I landed, chopped throttle and took off again and it was fine.

So should I have a throttle curve which never goes to zero in flight, or is this a bug in the v4.7 firmware, and gyro's should only reset on initial throttle up, not subsequent blips to zero throttle - I can see this being more of a problem if you had a radio hold in flight, rx will go to failsafe zero throttle, when you hopefully regain radio link, you could end up with a hard to fly if not unflyable quad ??

chansen1953
12-30-2011, 05:05 PM
james,

good point !.. it does not seem to happen with my FF board.. but I must admin, I have not actually cut throttle right off in flight..

you could try using the throttle trim or hover/throttle trim to set this motor point.. (dx7)

ie: on power up and arming, the throttle is at zero, and trim at lowest. but set the trim so that for takeoff you move the trim up till the motors spin, and then start flying.. at this setting , if you goto zero throttle, it will not actually STOP, but still be ticking over.. so maybe no gyro reset ?? worth a try ?

Tomstoy2
12-31-2011, 01:59 AM
+1

jamesb72
01-03-2012, 09:20 AM
I can easily use idle up to have a throttle curve which doesn't go below motor idle for flying - just wondered if everyone else does this ??

Tomstoy2
01-03-2012, 11:33 AM
No problem with that. When you mount a camera pan/tilt, lights, and other stuff the more channels you need to control everything. Comes a time you might want that channel for something else, ( if your radio allows you to re-assign ).

Usually, throttle curves are linear, as you're not swinging a big heavy rotor like a heli, just small light props.
Experiment with expo on throttle to get the smoothness you desire.

Jonny.Smith
01-03-2012, 05:17 PM
Im not an expert to this subject, but there are some settings for ESC's (normal, soft and supersoft), may be this may help (even if related to start, but there are "3 seconds" has been mentioned)?

lperagallo
01-03-2012, 09:01 PM
Im not an expert to this subject, but there are some settings for ESC's (normal, soft and supersoft), may be this may help (even if related to start, but there are "3 seconds" has been mentioned)?

Do not use anything other than 'normal' throttle startup with any multirotor. You will crash if the ESC can't immediately change the throttle output to the motors.

Lou