Newbie question about number of channels

[Patrick Free]

Forgive my wrong terminology.

So, a 8-channel radio covers what exactly?

1) Throttle
2) Heading (tail rotor)
3) swashplate L-R
4) swashplate F-B
5) Collective

What are the other three channels for?

[Andy Beetz]

"Patrick Free" <not@nowhere.com> wrote in message
news:MPG.1b158bb41659522d9896ab@news-server.austin.rr.com...
>
> Forgive my wrong terminology.
>
> So, a 8-channel radio covers what exactly?
>
> 1) Throttle
> 2) Heading (tail rotor)
> 3) swashplate L-R
> 4) swashplate F-B
> 5) Collective
>
> What are the other three channels for?

Whatever you like, you only really need the 5 (and in some cases only 4). If
you have spare channels you can use them to do things like change your gyro
gain and/or modes (between standard and heading hold), to control a
headspeed governor or even adjust your engine mixture 'on the fly' so to
speak.

Andy

[Patrick Free]

In article <40abd865$0$4578$db0fefd9@news.zen.co.uk>,
the_flc@zenREMOVETHIS.co.uk says...
>
> "Patrick Free" <not@nowhere.com> wrote in message
> news:MPG.1b158bb41659522d9896ab@news-server.austin.rr.com...
> >
> > Forgive my wrong terminology.
> >
> > So, a 8-channel radio covers what exactly?
> >
> > 1) Throttle
> > 2) Heading (tail rotor)
> > 3) swashplate L-R
> > 4) swashplate F-B
> > 5) Collective
> >
> > What are the other three channels for?
>
> Whatever you like, you only really need the 5 (and in some cases only 4). If
> you have spare channels you can use them to do things like change your gyro
> gain and/or modes (between standard and heading hold), to control a
> headspeed governor or even adjust your engine mixture 'on the fly' so to
> speak.
>
> Andy
>
>
>

Ah, ok. Thanks for clearing that up. With respect to collective
(helicopters that aren't fixed), is that usually controlled manually, or
does the radio mix in that with the throttle control?

And, in a related question, how do you do these other things, like
adjust engine mixture? The radios I see have two joysticks, so what
control do you use for those other channels?

Thanks!

Patrick

[Mike]

>Ah, ok. Thanks for clearing that up. With respect to collective
>(helicopters that aren't fixed), is that usually controlled manually, or
>does the radio mix in that with the throttle control?
>
>And, in a related question, how do you do these other things, like
>adjust engine mixture? The radios I see have two joysticks, so what
>control do you use for those other channels?
>
>Thanks!
>
>Patrick
>
>
Certainly on modern transmitters these days, you control throttle and
collective on one stick, but individually program each servo for exactly how
much movement you give each one. Throttle and pitch curves also allow you to
specify differential movement (eg more servo movement for the first half of the
stick, and less at the top, or vice versa. This is quite a powerful function
when you use both curves together).

You will find that most transmitters will have rotary controls, and auxiliary
switches, for control of the other channels.
If you buy one and it hasn't got any, it probably won't be suitable for
helicopter flying.

Mixture control is not something a lot of heli pilots use, but gyro gain and
retractable undercarriages would certainly be candidates.

[Patrick Free]

In article <40ac5e68$0$4576$db0fefd9@news.zen.co.uk>,
the_flc@zenREMOVETHIS.co.uk says...
> Basically the throttle stick controls the throttle and collective together
> at the same time. You as the user has to put in the throttle curve and pitch
> curve. The curves basically tell the tranny what output to give to the
> relevant servo at any particular throttle stick setting. Sorry if this is
> vague, if you have problems with this part I'm sure someone else can explain
> better.
>

That makes sense. If I recall correctly, on a real helicopter the
collective is a "motorcycle grip" type control that is part of the
throttle, which moves back and forth.

Do RC heli flyers ever control collective manually? Or is that just in
autorotation?

Patrick

[Andy Beetz]

"Patrick Free" <not@nowhere.com> wrote in message
news:MPG.1b1683ce11d5cfeb9896ad@news-server.austin.rr.com...
> In article <40ac5e68$0$4576$db0fefd9@news.zen.co.uk>,
> the_flc@zenREMOVETHIS.co.uk says...
> > Basically the throttle stick controls the throttle and collective
together
> > at the same time. You as the user has to put in the throttle curve and
pitch
> > curve. The curves basically tell the tranny what output to give to the
> > relevant servo at any particular throttle stick setting. Sorry if this
is
> > vague, if you have problems with this part I'm sure someone else can
explain
> > better.
> >
>
> That makes sense. If I recall correctly, on a real helicopter the
> collective is a "motorcycle grip" type control that is part of the
> throttle, which moves back and forth.
>
> Do RC heli flyers ever control collective manually? Or is that just in
> autorotation?
>
> Patrick

It would depend on what you mean by manually. To make any sense of that
right now, the answer I would give is 'well, we manually move the throttle
stick which thereby causes the pitch servo to move.'. However if you mean do
we ever use it independently from the throttle then I guess yes as when you
hit throttle hold, the throttle stick is only controlling the collective.
Same applies if the engine happens to quit.


Andy

[Tim]

Patrick Free wrote:
> In article <40ac5e68$0$4576$db0fefd9@news.zen.co.uk>,
> the_flc@zenREMOVETHIS.co.uk says...
>> Basically the throttle stick controls the throttle and collective
>> together at the same time. You as the user has to put in the
>> throttle curve and pitch curve. The curves basically tell the tranny
>> what output to give to the relevant servo at any particular throttle
>> stick setting. Sorry if this is vague, if you have problems with
>> this part I'm sure someone else can explain better.
>>
>
> That makes sense. If I recall correctly, on a real helicopter the
> collective is a "motorcycle grip" type control that is part of the
> throttle, which moves back and forth.
>
> Do RC heli flyers ever control collective manually? Or is that just
> in autorotation?
>
> Patrick

There's an issue of terminology here I think. You shouldn't think of the
left stick as the "throttle", but rather the "collective". It is the
collective pitch (and tail rotor) that you are really controlling with that;
although the throttle is to a certain extent controlled by the left stick as
well, it basically just follows the collective, the idea being to match the
throttle to collective such that the rotor head speed remains more or less
constant throughout the pitch range (which is pretty much the idea in a full
size heli too). On my heli, I have a governor fitted and that looks after
the throttle for me, so the left stick IS just controlling collective, once
the engine is up to speed.

(People who have backgrounds in fixed wing tend to refer to the left stick
as the throttle as that's what it does in a fixed wing model.)

Tim


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[Beav]

"Patrick Free" <not@nowhere.com> wrote in message
news:MPG.1b1683ce11d5cfeb9896ad@news-server.austin.rr.com...
> In article <40ac5e68$0$4576$db0fefd9@news.zen.co.uk>,
> the_flc@zenREMOVETHIS.co.uk says...
> > Basically the throttle stick controls the throttle and collective
together
> > at the same time. You as the user has to put in the throttle curve and
pitch
> > curve. The curves basically tell the tranny what output to give to the
> > relevant servo at any particular throttle stick setting. Sorry if this
is
> > vague, if you have problems with this part I'm sure someone else can
explain
> > better.
> >
>
> That makes sense. If I recall correctly, on a real helicopter the
> collective is a "motorcycle grip" type control that is part of the
> throttle, which moves back and forth.

Throttle on full size is a twist grip, but collective is achieved by pulling
the lever up or pushing it down. The collective lever has the twist grip on
th' end of it.
>
> Do RC heli flyers ever control collective manually? Or is that just in
> autorotation?

It's been done, but these days there's absolutely no need to get into such
complication (from aa flying point of view). Even the cheapest heli radio's
are capable of doing the mixing internally, and if you add in a governor,
then it's even better.


--
Beav


Please note my E-mail address is "beavis dot original at ntlworld dot com"
(with the obvious changes)

Beavisland now lives at
www.beavisoriginal.co.uk