Headspeed problem???
01-25-2007 | 10:11 PM
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From: ABQ,
NM
Headspeed problem???
when i am hovering(or trying to) the heli tends to go to the left which i understand is natural but when i make a tiny adjustment to fix it, the heli drops as if the head speed or pitch dropped and was not creating any lift. Can anyone explain??
thanks alot
thanks alot
01-25-2007 | 10:25 PM
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From: , FL
RE: Headspeed problem???
on some helis, making course corrections can cause the blades to lose rpm's. try giving it a little power when making corrections, if that doesnt work consider buying a better swashplate
01-26-2007 | 06:03 AM
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From: Miamisburg,
OH
RE: Headspeed problem???
Mine dose the same thing. You must work the left stick to regulate the power. When I make larger corrections I also feed moer power and then after heli corrects I reduce power to try to keep level hover.
01-26-2007 | 09:26 AM
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From: San Jose,
CA
RE: Headspeed problem???
I have explained this before in a prev. post:
The reason why you loose altitude when applying any cyclic (pitch and/or roll) is because of Newton's Third Law of motion. To every action there is an equal and opposite reaction. So, when you lift off into a hover you have lift which is energy in motion (Kinetic Energy). When you apply forward pitch you are turning that lift energy into forward flight. You must trade one for the other, you cannot have both. You will automatically start to loose lift because you are turning that lift into forward motion. To keep from loosing lift you need to apply more collective, or add more energy into your flight. When you start to level out you will gain lift because you are turning forward flight back into lift, so therefore you must ease off the collective. This happens for all cyclic movements. When flying you must continuously manage these tradeoffs of energy. This is what makes flying a helicopter so fun.
The reason why you loose altitude when applying any cyclic (pitch and/or roll) is because of Newton's Third Law of motion. To every action there is an equal and opposite reaction. So, when you lift off into a hover you have lift which is energy in motion (Kinetic Energy). When you apply forward pitch you are turning that lift energy into forward flight. You must trade one for the other, you cannot have both. You will automatically start to loose lift because you are turning that lift into forward motion. To keep from loosing lift you need to apply more collective, or add more energy into your flight. When you start to level out you will gain lift because you are turning forward flight back into lift, so therefore you must ease off the collective. This happens for all cyclic movements. When flying you must continuously manage these tradeoffs of energy. This is what makes flying a helicopter so fun.
01-26-2007 | 12:41 PM
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From: Bakersfield,
CA
RE: Headspeed problem???
CALCOP.. I dont think that is what he is talking about.
I completely understand how a heli works, and mine does the same thing. When making adjustments, the heli main rotor loses speed and the heli will fall like a rock until you are done. I almost hit the ground the first time I noticed this... but once I got the adjustment corrected, the heli flew normal.
Mine did it and I was only trying to trim out the tail rotor... (heli was not leaning) It was causing my heli to turn left... So I used my trim adjustment on the control and that is when i had a spike in power and my heli almost fell out of the sky, until the power came back to the main rotors..
Although, he did call it Headspead problem... So I could be wrong.. And if it is when you are trying to move forward, Lean left, lean right, lean back, your heli will drop... Like Calcop said.. unless you give it more power..
I completely understand how a heli works, and mine does the same thing. When making adjustments, the heli main rotor loses speed and the heli will fall like a rock until you are done. I almost hit the ground the first time I noticed this... but once I got the adjustment corrected, the heli flew normal.
Mine did it and I was only trying to trim out the tail rotor... (heli was not leaning) It was causing my heli to turn left... So I used my trim adjustment on the control and that is when i had a spike in power and my heli almost fell out of the sky, until the power came back to the main rotors..
Although, he did call it Headspead problem... So I could be wrong.. And if it is when you are trying to move forward, Lean left, lean right, lean back, your heli will drop... Like Calcop said.. unless you give it more power..
01-26-2007 | 01:08 PM
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From: , FL
RE: Headspeed problem???
its also because of the friction in the bearings. when the prop is at extreme angles, the bearing in the swashplate will rub against the plastic / CNC casing. this doesnt cause a loss in power. however, it does require more power to keep the same blade speed. if this is the problem, putting a drop of grease or oil on the bearings can help... if its a headspeed problem, consider adjusting the trim on your radio and checking that your servos are properly working and making a complete, steady sweep.
in reply to calcop's post, u are right on what u said. but in order for the heli to loose that much lift, the blade has to be at an angle that overcomes the energy from the lift. there must be at least a 49:51 % ratio of energy for one to counteract the other... in otherwords, just because u move forward doesnt mean u loose lift, it just means the direction of the energy (in this case, moving air) is being transfered, creating forward thrust.
in reply to calcop's post, u are right on what u said. but in order for the heli to loose that much lift, the blade has to be at an angle that overcomes the energy from the lift. there must be at least a 49:51 % ratio of energy for one to counteract the other... in otherwords, just because u move forward doesnt mean u loose lift, it just means the direction of the energy (in this case, moving air) is being transfered, creating forward thrust.
01-26-2007 | 09:21 PM
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From: Virginia Beach,
VA
RE: Headspeed problem???
My Swash does the same thing you just mentioned.. (original and new one) The bearing cover on the top side rubs against the main rotor shart when at full left/right stick! Whatta Pain.. at low RPM's it does cause loss of power/headspeed but doesn't seem too bad at 50%+ throttle.
01-26-2007 | 09:29 PM
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From: Wolf Point,
MT
RE: Headspeed problem???
Another reason for the bobbing is a problem common to all CCPM heads--control interaction. Try this: turn on your transmitter and plug in the battery; with the throttle off, move only the right stick. Move it left to right, back and forth, and in circles. Watch the 'ball' in the center of the swashplate; anytime it bobs up and down while you're only moving the right stick, you are getting unwanted pitch input to the flybar.
With a better radio, you can mix the cyclic and pitch to minimize the effects of interaction. With the stock radio you're kinda stuck with the setup they provide stock.
Aside from mixing out the interaction with my Futaba 9C, I've also set the aileron and elevator endpoints to avoid the plastic part of the swash contacting the shaft at the extremes.
With a better radio, you can mix the cyclic and pitch to minimize the effects of interaction. With the stock radio you're kinda stuck with the setup they provide stock.
Aside from mixing out the interaction with my Futaba 9C, I've also set the aileron and elevator endpoints to avoid the plastic part of the swash contacting the shaft at the extremes.
01-27-2007 | 12:46 AM
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From: Colorado Springs,
CO
RE: Headspeed problem???
Do you guys actually hit the mainshaft with the swash in flight? I usually make small pitch changes and corrections during flight and only use extreme pitch (enough to hit the mainshaft) during a pre-flight check to make sure everything is okay and nothing is binding.
01-31-2007 | 07:50 PM
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From: Virginia Beach,
VA
RE: Headspeed problem???
Do I hit the swash cover on the main shaft while flying?... Well.. Flipping her over, doing TicToc's, Hurricanes, etc...
J/K. No, just noticing it when checking travel of the servos. I've also installed the hs-55's and adjusted the swash linkage so it just Barely... Barely.. could touch the main rotor shaft at extremes. I haven't checked, but I bet I threw the default pitch off on the main blades doing so too.. lol. Still flies fine, might just lift off a little sooner. Idle Up seems to have the same negative pitch as before.
02-01-2007 | 02:47 PM
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From: Charlotte,
MI
RE: Headspeed problem???
ORIGINAL: Savage_Wolf
its also because of the friction in the bearings. when the prop is at extreme angles, the bearing in the swashplate will rub against the plastic / CNC casing. this doesnt cause a loss in power. however, it does require more power to keep the same blade speed. if this is the problem, putting a drop of grease or oil on the bearings can help... if its a headspeed problem, consider adjusting the trim on your radio and checking that your servos are properly working and making a complete, steady sweep.
in reply to calcop's post, u are right on what u said. but in order for the heli to loose that much lift, the blade has to be at an angle that overcomes the energy from the lift. there must be at least a 49:51 % ratio of energy for one to counteract the other... in otherwords, just because u move forward doesnt mean u loose lift, it just means the direction of the energy (in this case, moving air) is being transfered, creating forward thrust.
its also because of the friction in the bearings. when the prop is at extreme angles, the bearing in the swashplate will rub against the plastic / CNC casing. this doesnt cause a loss in power. however, it does require more power to keep the same blade speed. if this is the problem, putting a drop of grease or oil on the bearings can help... if its a headspeed problem, consider adjusting the trim on your radio and checking that your servos are properly working and making a complete, steady sweep.
in reply to calcop's post, u are right on what u said. but in order for the heli to loose that much lift, the blade has to be at an angle that overcomes the energy from the lift. there must be at least a 49:51 % ratio of energy for one to counteract the other... in otherwords, just because u move forward doesnt mean u loose lift, it just means the direction of the energy (in this case, moving air) is being transfered, creating forward thrust.
in other words when you are in a hover the helis thrust is downward and when you attempt to start forward flight that thrust changes to forward thrust ! thus you have to balance fwd and upword thrust to maintain flight ! would that be correct ?
