Must Know for Heli Fliers - SWASH BINDING

Started by deepikarun, October 31, 2010, 01:52:31 PM

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deepikarun

Problem:
On applying FULL aileron AND elevator, the swash plate binds. All the linkages are exact, and all the ball links are in good working order. Full aileron doesn't cause it to bind and Full elevator doesn't cause it to bind. Only when the two are used together does it bind. The collective has no impact on any of this.

Clarification:
That's because the TX stick is made to work for airplanes. Note that its range of motion is a square. You can move the ailerons full blast and that's entirely separate from the elevator, which can simultaneously be moved full blast. But on a heli we don't have two separate gadgets connected to that stick, we have only one thing, the swash. It can tilt just so far in any direction. Its range of motion is bounded by a circle rather than a square. If you have the endpoints set to max for aileron only and elevator only, then you have a situation like this... the circular limit of the swash is INSIDE of the square of the TX control. This means that when you move the TX stick into a corner you're outside the range of the circle and binding happens. The "cyclic ring" keeps the TX stick within the circle. Alternatively, you can reduce the aileron/elevator to about 70% of max, which put the square of the TX stick INSIDE of the circular limit of the swash. In that case the corners don't exceed the limit of the swash, but you don't have max control otherwise. That's no big loss unless you want all you can get out of it.

Here is the picture of the cyclic ring.
Arun
JR XG8, Hirobo Sceadu EVO 50, TRex 600, Phoenix Tiger.

deepikarun

Arun
JR XG8, Hirobo Sceadu EVO 50, TRex 600, Phoenix Tiger.

anwar

#2
This is not normally needed, as it can be taken care of by proper setup of the head (physical and radio). It is also rare that both ailerons and elevator are together taken to the extremes in doing maneuvers.  Controlling that movement is part of the behavior that is gained with experience (doing maneuvers without excessive stick movement).

On a related note, many high end radios have this functionality built into the software.  It can help with initial training of maneuvers like piro flips.
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sujju

am sorry i dint get your query if there is any..?
in the fbl systems... eg.. mikado vbar the swash ring is taken care within the software program itself... one needs to input the values of the swash ring / cyclic ring to eliminate swash binding...
for the flybarred ones i just play with endpoints to get the required inputs...  am not sure if the fastlad accessory is needed?...
CEO
RcBazaar

deepikarun

I am not in favour of the ring and understand that in real flight one never go to those extremes(I mean the corners).

While I changed the servos on my heli I checked the binding on the cyclic and found that full up down and right left was perfect and when I applied full left and up together (top left corner) the servos were binding. I talked to some of the experienced guys about this and most of them only said that it shouldn't happen and there is something wrong with the setup.

Finally while searching on the net I stumbled upon this piece of information according to which it is normal. The advanced radios does compensate for the cyclic ring but with a normal radio it is otherwise.

Hi Sujju, Yes you can stop the binding by adjusting the ATVs for the cyclic servos but that way you are reducing the full cyclic deflection otherwise available.

Anwar Ji - Controlling that movement is part of the behavior that is gained with experience (doing maneuvers without excessive stick movement). ==> Thats the key and as expected coming from one of the most experienced person in this Forum.  :salute:
Arun
JR XG8, Hirobo Sceadu EVO 50, TRex 600, Phoenix Tiger.

sujju

what cyclic pitch are you looking at ?... i flymine with 10deg and with this never had any binding issues with the collective pitch being at the extremes... if not atv (which is the wrong thing to do to get the cyclic pitch) play around with you swash on the ail and elev???
CEO
RcBazaar

deepikarun

Quote from: sujju on November 01, 2010, 11:20:43 PM
what cyclic pitch are you looking at ?... i flymine with 10deg and with this never had any binding issues with the collective pitch being at the extremes... if not atv (which is the wrong thing to do to get the cyclic pitch) play around with you swash on the ail and elev???

Hi Sujju,

Nothing to do with the collective. I am talking about the elevator and aileron.

When you push the cyclic stick (Elevator & Aileron) to the extreme corners of your radio.

+10 you are talking about the collective pitch.

Thanks

Arun

Thanks
Arun
JR XG8, Hirobo Sceadu EVO 50, TRex 600, Phoenix Tiger.

sujju

no... am talking about the cyclic 10deg.. not the collective which i fly - 12 and +12... the swash binding happens on the extremes of the collective... its this...
with a full positive 12 deg collective and full cyclic aile or elev you will end up with 22 deg this is where the binding tends to happen unless the setup is correct... when you fly you heli dont jsut look at the collective but also measure you cyclic (pls check on the net on how to measure the cyclic - ail and elev if not i will upload some vids).. i think you have not set you cyclics thats where the binding is happening?
CEO
RcBazaar

deepikarun

The information is from the net only.

I would appeciate if you can upload some videos.

Thanks

Arun
Arun
JR XG8, Hirobo Sceadu EVO 50, TRex 600, Phoenix Tiger.

sujju

CEO
RcBazaar