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Thread: Throttle Hold - throttle and pitch curves

  1. #1
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    Default Throttle Hold - throttle and pitch curves

    How does everyone set up their throttle and pitch curves when in throttle hold?
    Do you have them the same as the flight modes or something different, what is best for AP?

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    My throttle hold has no effect on pitch curve.
    My throttle hold only kills the motor.
    Last edited by nooobs; 02-23-2010 at 01:39 PM.

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    Actually, mine is set with a wider pitch range than my standard AP pitch curve for autos. A little more negative and full positive. I don't remember the exact settings.

    Tip
    It's all of the little things that make the big things happen.

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    Just to add
    My flight mode switch has no effect on pitch curves.
    I control pitch curves on a separate switch.

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    That makes sense Nooobs. So when you're shooting AP and have to auto for whatever reason, do you hit both switches or just stay in the current pitch curve and cut the throttle?

    Tip
    It's all of the little things that make the big things happen.

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    I only cut throttle and stay in the current pitch curve.

    My first pitch setting (first position on a three-way switch) is set to -4. This is more than enough for a 24lb heli.

    Second setting is -5.5 and third is -7. That's for a really bad situation.
    Last edited by nooobs; 02-23-2010 at 02:14 PM.

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    So your flight mode only changes HS?

    I may be missing something but am curious as to the reason for not having the pitch curve in throttle hold set to the maximum neg and pos pitch, say -7 + 10? then as soon as you hit throttle hold it cuts the motor and you have the full pitch range you would want in those really bad situations by flipping a single switch.

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    So your flight mode only changes HS?
    Yes.


    I may be missing something but am curious as to the reason for not having the pitch curve in throttle hold set to the maximum neg and pos pitch, say -7 + 10? then as soon as you hit throttle hold it cuts the motor and you have the full pitch range you would want in those really bad situations by flipping a single switch.
    Let's say you've set your regular flying pitch curve to -2 to +9 and throttle hold setting to -7 to +10. When you hit throttle hold, depending on the position of your collective, your heli can either jump or drop unexpectedly.

    If the heli jumps then you'll lose head speed and hopefully you have enough altitude to gain it back.

    If the heli drops and you're close to the ground then...

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    good point!! I think I might do the same


    What about the throttle curves?
    I'm still fairly new to the 14MZ but I have a 0,50,50,50,50 curve in normal and a 0,75,75,75,75 curve in idle-up 1. But I have noticed that the throttle hold curve has adopted the same curve as in normal mode, so even if in idle-up 1, when I flip the throttle hold switch, the curve changes back to 0,50,50,50,50.

    Does this sound right?

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    Hi all,

    When you say "kill throttle", are you completely shutting off current to the motor, or just bringing it back to idle?

    Cheers,
    Jeff

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    Normal should be 0-?-?-?-?
    IDLE1 and 2 should be straight across.
    For example IDLE1- 75 across. IDLE2 - 100 across.

    You should never fly in Normal mode.

    When flipping throttle hold it won't matter what the throttle curve does as the motor is killed.

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    Hi guys,

    I thought I would chime in here and see if I can help. My AP or AV set up is almost identical to my F3C contest machines. To give yourself the best chance of safely landing a heavy AP or AV machine you need to have +13 to +14 degrees of positive pitch, no matter what blades you are running. My machines always have 13.5 degrees of positive pitch for throttle hold. You want the rotor blades to make usable lift down to the slowest rpm possible. If you only have 9 or 10 degrees of pitch available and you have to do an auto in anything but perfect conditions the model is going to hit the ground pretty hard. With 13.5 degrees of pitch you can make safe landings that would have been impossible with only 9 or 10 degrees.

    Your model should hover at half stick. Adjust your pitch curve so that you are hovering at half stick. Once you get that, adjust the pitch curves for all idle ups and throttle hold so that they are the same at half stick. This way if or when you have to hit throttle hold the model won't jump.

    If you set the model up this way you don't have to have so much pitch in your normal flight mode. My idle ups (flying around modes) for my AP and AV machines have just enough pitch on top so that I can get out of trouble, if I get to settling straight down too fast or if I have to make a downwind approach, which requires more pitch to be able to stop the model at the bottom of the decent. A model set up this way is very smooth on collective and much easier to fly precisely.


    Wayne Mann

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    Quote Originally Posted by jeffscholl View Post
    Hi all,

    When you say "kill throttle", are you completely shutting off current to the motor, or just bringing it back to idle?

    Cheers,
    Jeff
    Electric model has no need for idle.

    I generally add more negative on throttle hold so the helicopter doesn't float too much.

    Wayne Mann: Good idea about the 14 degree positive pitch.
    Last edited by HansenTsang; 02-23-2010 at 09:17 PM.

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    I have idle 1 and 2 setup at an "idle" speed to keep the ESC from going into soft start mode in low stick since I'm using the governer.

    Tip
    It's all of the little things that make the big things happen.

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    Wayne can i ask how much negative pitch you use for T Hold?

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    Jeff
    Sorry I didn't see your post. Yes as Hansen explained.


    Wayne
    Yes I have mine set up just as you have explained except my throttle hold does not control my pitch. I like to have things separate.

    I do max out my pitch on the Maxi but it's not close to your +13 recommendation. Mine tops out at +11 with the Profi before it binds. I think the Joker tops out, normally, at +12.5 from what I can remember from Gerd.

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    Hopefully none of us will ever HAVE to hit throttle hold. Only practice.

    Tip
    It's all of the little things that make the big things happen.

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    Quote Originally Posted by Monterey_Tip View Post
    Hopefully none of us will ever HAVE to hit throttle hold. Only practice.

    Tip
    Actually I hate practicing throttle hold. So when I flip the throttle hold switch I usually really needs it.

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    My .02 is throttle hold on idle.

    If I accidently hit the throttle hold during flight I don't have to wait the precious seconds to re-start.
    Same goes for practicing autos when you need the juice right away for bail outs.

    Whew, 14degs...with a bit of cyclic at the bottom a blade could be around 16-17 degrees.

    Cheers,
    Jeff
    Last edited by jeffscholl; 02-24-2010 at 11:34 AM.

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    Quote Originally Posted by jeffscholl View Post
    My .02 is throttle hold on idle.

    If I accidently hit the throttle hold during flight I don't have to wait the precious seconds to re-start.
    Same goes for practicing autos when you need the juice right away for bail outs.

    Whew, 14degs...with a bit of cyclic at the bottom a blade could be around 16-17 degrees.

    Cheers,
    Jeff
    You are correct. Some flyers like to leave the throttle at 5 to 10 percent on the bottom in those cases.

    I also use the throttle hold switch as a dis-arming switch for the throttle while on the ground so I have it set to full stop.

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    I've never tryed bailing out of an auto with an electric heli, always been scared that it would strip the main gear when starting up again.

    I don't have soft-start activated on my ESC so I don't think getting the motor back up to speed would be a problem, just the stripping of the main gear?


    Would there be a risk of this or has nobody ever had an issue?

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    Quote Originally Posted by crcr View Post
    I've never tryed bailing out of an auto with an electric heli, always been scared that it would strip the main gear when starting up again.

    I don't have soft-start activated on my ESC so I don't think getting the motor back up to speed would be a problem, just the stripping of the main gear?


    Would there be a risk of this or has nobody ever had an issue?
    If you plan to practice auto with an electric it is better to dial in a bit of throttle like 5 to 10 percent. That way you won't be working the mechanics too hard.

    Stripping the main gear is not that frequent when you bail out. The reason is that the head is still spinning. So you are not starting from a dead stop.

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    Chris,

    As heavy as these things typically are, -3 degrees is usually enough. I have right at -4 degrees in my machines for AP and at -4 they come down like a rock. I just use the collective stick to regulate the decent rate.

    Jeff,

    At the bottom of an auto you are not going to be jumping on cyclic pitch. I have never had the rotor blades stall at the bottom of an auto and the machine just fall to the ground for the last couple feet. I have had many machines with too little positive pitch get to the bottom and just run out of lift and hit the ground rather hard from a lack of pitch.

    Nooobs,

    If your throttle hold does not effect the pitch curve, I will assume that you throw another switch which increases your pitch range?


    Wayne Mann

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    If your throttle hold does not effect the pitch curve, I will assume that you throw another switch which increases your pitch range?
    Correct.

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    Hi all,
    I would check if there is enough lift of your rotor when you auto. While on the ground bring collective to almost 1/2 stick (barely lifting off) then hit throttle hold. Then, start giving collective and observe how the whole thing reacts. If you can lift off your AP ship for 2 or 3 seconds then you may be able to auto land safely in an emergency. If not, then you will not be able to slow down the descent rate and that will be a problem.
    Either your AP platform is way too heavy (like mine) or your head speed is too low or your blades are too small.
    Cheers,
    Ahmet

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