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Old Apr 14, 2005, 04:37 PM
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United States, WA, Olympia
Joined Mar 2005
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Fix tail wag with mix or gain?

I have a HB V3 with the all in one board. I put some like90s on it but then it started to spin counter clockwise. My guess was that it didn't need as much counter to keep the nose straight so I adjusted the mix just a bit lower. What I have found is that it doesn't seem to make an adjustment until you unplug the battery and plug it back in. Also the adjustment is so touchy you can turn it just enough to see the screw move and it acts like you turned it all the way up. Now I have a little wag in the tail. Should I be adjusting the mix or the gain??? to get rid of this? One last thing. When I got the like90 blades I also got their GWS 300H motor as recomended. I never before had any glitches but now I do. It it the new motor making the glitches? -Sorry a little frustrated with how it's flying right now.
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Old Apr 14, 2005, 05:31 PM
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Battle Creek Mi
Joined Jan 2005
760 Posts
Hi Sky Captian, your v3 will fly pretty well when she gets tuned. Your right about making adjustments and then having to "reboot" the system. As far as counterclockwise , I assume you mean the heli not the blades? If the heli moves counter clock wise, yes, you will need to raise or lower the mix. Little tiny adjustments! Gain is probably too high if you have tail wag. turn it down a little at a time until the wag stops. Mix controls your main to tail rotor speed ratio....it increases or decreases your tail rotor speed in relation to how fast the main rotor is turning. This helps keep the nose more or less straight when you apply or decrease the throttle in flight. Make small adjustments witht he trim on your transmitter.
Hope this helps, Crewdogg
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Old Apr 14, 2005, 05:31 PM
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Tintin's Avatar
Akershus, Norway
Joined Mar 2005
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Normally reducing gain will reduce wagging
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Old Apr 14, 2005, 06:12 PM
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United States, WA, Olympia
Joined Mar 2005
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If I understand correctly. The mix is the amount of power the rear motor and the gain is the ratio of main to rear power in relation to your throttle position. Did I get it right?

The mix is entirely too sensitive to adjustments. Bad engineering if you ask me.
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Old Apr 14, 2005, 07:25 PM
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Joined Aug 2003
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The mix is the amount of power that goes to the tail motor relative to the throttle position... basically as the main rotor turns it places torque on the body so it wants to rotate in the opposite direction to the blades. The tail motor is used to counteract this torque. Obviously the faster the main blades turn, the greater the torque and hence the greater the power required from the tail motor to keep the heli from rotating.

If the mix is too high, the tail motor will produce more torque than the main rotor and the heli will rotate clockwise (assuming the main rotor turns clockwise), if the tail doesnt put out enough power, the main rotor torque will still make the heli turn anticlockwise.

So what you need to do (assuming the rotors turn clockwise looking at them from above, if theyre going the other way (unlikely) then reverse these directions):

Try to take off with the heli into a hover, ignoring the wag, which way does the heli want to turn in hover, if it rotates clockwise, decrease the proportional (LITTLE BIT AT A TIME OR YOU WILL BE GOING BACK AND FORTH), if it rotates anti-clockwise increase the proportional.

Now the gain is used to determine how strongly the tail will react to unwanted rotation/movement of the tail... i.e. the heli is throttled up and the tail is spinning, then a gust of wind comes trying to blow the tail around, the gain will determine how strongly the heli responds to this wag, the higher the gain the more power the tail will put out for any given rotation...

The wag comes from this gain being too high. Think about being in a car on an open parking lot. There is a white line 30 meters in front of you where you want to get to and stop at... Gain here would be how hard you hit the gas... if you hit it too hard your going to go past the white line, then have to reverse... if you reverse as hard again, your going to need to go forward again, back and forth oscillating... however if you accelerate too slowly you'll never get there and (in the case of a heli) if the white line is moving all the time, your response will be for naught and you may as well not try (not have a gyro)...

So in summary for gain... if the tail is wagging, your gain is too high (mine wags only ever so slightly as it gives the fastest response) for propotional take off and make adjustments with the proportional till the heli doesnt want to turn one way of the other (this should be done with zero rudder trim). Later on as the battery goes flat you may add trim as you fly but for setting up its best if its at zero and you have your full trim range available...

Hope this helps.
Will.
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Old Apr 14, 2005, 07:26 PM
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Joined Aug 2003
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Sorry in response to your question, no you are wrong.. yes the pots are sensetive, a fraction of a turn is all that is needed at a time unless its WAY off and even then, a max 1/4 of a turn at a time is recommended.
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Old Apr 15, 2005, 11:17 AM
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United States, WA, Olympia
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Thanks for the great explanation Cerberus. As for the pots. I'm not even moving it a 1/16 of a turn and getting a huge change. I think if I look at it wrong it will move
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