help...idle-up

[david]

Just trying to create my very first idle-up curve (giving c +10, 0, -10 I
guess at 100%, 40%,100% throttle with the 40% in the centre of throttle
throw), but a friend I met at the field told me that I must ensure the
blades don't jump when I flick the switch, or the engine can stall. Now,
how do I ensure the blades don't jump in pitch when I change curves? The
normal and idle-up curves are quite different aren't they...so how?

David

[Chopper]

Hi David,
More than 1 way to get round this problem. The easiest is to just ensure you
are climbing when you go into idle up.The jump won't be quite so noticeable.

Another way, and this will involve changing your "normal" settings.
At present you probably hover at mid stick say 5 degrees pitch. In a true 3d
idle up curve mid stick equates to 0 degrees, hence the jump. What you could
do is change your normal curve so you hover at about three quarters stick.
Now when you change between normal and idleup there will be almost no jump.
though it does take a bit of getting used to hovering at 3/4 stick.

By the way, your friend was only partly correct, its most unlikely for the
engine to ever stall just by going into idleup.(assuming an engine with a
correctly set up carb)

Regards Steve

"david" <david_perry@btconnect.com> wrote in message
news:bbddam$e30$1@hercules.btinternet.com...
> Just trying to create my very first idle-up curve (giving c +10, 0, -10 I
> guess at 100%, 40%,100% throttle with the 40% in the centre of throttle
> throw), but a friend I met at the field told me that I must ensure the
> blades don't jump when I flick the switch, or the engine can stall. Now,
> how do I ensure the blades don't jump in pitch when I change curves? The
> normal and idle-up curves are quite different aren't they...so how?
>
> David
>
>

[david]

Thanx Steve

D
"Chopper" <chopper@remove.blueyonder.co.uk> wrote in message
news:Q%rCa.3339$3Y3.21890262@news-text.cableinet.net...
> Hi David,
> More than 1 way to get round this problem. The easiest is to just ensure
you
> are climbing when you go into idle up.The jump won't be quite so
noticeable.
>
> Another way, and this will involve changing your "normal" settings.
> At present you probably hover at mid stick say 5 degrees pitch. In a true
3d
> idle up curve mid stick equates to 0 degrees, hence the jump. What you
could
> do is change your normal curve so you hover at about three quarters stick.
> Now when you change between normal and idleup there will be almost no
jump.
> though it does take a bit of getting used to hovering at 3/4 stick.
>
> By the way, your friend was only partly correct, its most unlikely for the
> engine to ever stall just by going into idleup.(assuming an engine with a
> correctly set up carb)
>
> Regards Steve
>
> "david" <david_perry@btconnect.com> wrote in message
> news:bbddam$e30$1@hercules.btinternet.com...
> > Just trying to create my very first idle-up curve (giving c +10, 0, -10
I
> > guess at 100%, 40%,100% throttle with the 40% in the centre of throttle
> > throw), but a friend I met at the field told me that I must ensure the
> > blades don't jump when I flick the switch, or the engine can stall.
Now,
> > how do I ensure the blades don't jump in pitch when I change curves?
The
> > normal and idle-up curves are quite different aren't they...so how?
> >
> > David
> >
> >
>
>

[Beav]

"david" <david_perry@btconnect.com> wrote in message
news:bbddam$e30$1@hercules.btinternet.com...
> Just trying to create my very first idle-up curve (giving c +10, 0, -10 I
> guess at 100%, 40%,100% throttle with the 40% in the centre of throttle
> throw), but a friend I met at the field told me that I must ensure the
> blades don't jump when I flick the switch, or the engine can stall. Now,
> how do I ensure the blades don't jump in pitch when I change curves?

Have ALL the pitch curves the same. It's the ONLY way to ensure there's no
change when you "Idle-up"

The
> normal and idle-up curves are quite different aren't they

Not if you set them all the same they're not :-)))

....so how?

See above


--
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

[Chopper]

Er Beav,
You want to be a little careful with that statement.-10 in a normal curve is
quite likely to get a beginner into a landing just slightly below ground
level.
Regards Steve

"Beav" <beavis.original@ntloxoworld.com> wrote in message
news:hnsCa.150862$vw6.1069675@news.easynews.com...
>
> "david" <david_perry@btconnect.com> wrote in message
> news:bbddam$e30$1@hercules.btinternet.com...
> > Just trying to create my very first idle-up curve (giving c +10, 0, -10
I
> > guess at 100%, 40%,100% throttle with the 40% in the centre of throttle
> > throw), but a friend I met at the field told me that I must ensure the
> > blades don't jump when I flick the switch, or the engine can stall.
Now,
> > how do I ensure the blades don't jump in pitch when I change curves?
>
> Have ALL the pitch curves the same. It's the ONLY way to ensure there's no
> change when you "Idle-up"
>
> The
> > normal and idle-up curves are quite different aren't they
>
> Not if you set them all the same they're not :-)))
>
> ...so how?
>
> See above
>
>
> --
> 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
>
>

[david]

"Chopper" <chopper@remove.blueyonder.co.uk> wrote in message
news:lwsCa.3387$bZ3.21912728@news-text.cableinet.net...
> Er Beav,
> You want to be a little careful with that statement.-10 in a normal curve
is
> quite likely to get a beginner into a landing just slightly below ground
> level.
> Regards Steve
>
> "

Yes it is, but modifying Beavs statement so that the positive side of the
curves are the same is going work isn't it?i.e. all above half throttle
stick posn.

David

[Chopper]

"david" <david_perry@btconnect.com> wrote in message
news:bbdki6$qar$1@hercules.btinternet.com...
>
> "Chopper" <chopper@remove.blueyonder.co.uk> wrote in message
> news:lwsCa.3387$bZ3.21912728@news-text.cableinet.net...
> > Er Beav,
> > You want to be a little careful with that statement.-10 in a normal
curve
> is
> > quite likely to get a beginner into a landing just slightly below ground
> > level.
> > Regards Steve
> >
> > "
>
> Yes it is, but modifying Beavs statement so that the positive side of the
> curves are the same is going work isn't it?i.e. all above half throttle
> stick posn.
>
> David
>
>

Yes very true David, That should work well.
Regards Steve

[Beav]

"Chopper" <chopper@remove.blueyonder.co.uk> wrote in message
news:lwsCa.3387$bZ3.21912728@news-text.cableinet.net...
> Er Beav,
> You want to be a little careful with that statement.-10 in a normal curve
is
> quite likely to get a beginner into a landing just slightly below ground
> level.

No mention of learning to fly was made Steve, just how to stop the jump when
switching into ans out of Idle up, and there IS only one way to guarantee it
doesn't and that's to have the same pitch curve on all the modes. Now it's
not what I'd recommend (but he didn't ask for recommendations of he BEST way
to go about setting up Idle-up modes, just how to stop it jumping)

Also, one has to make the assumption that he means at any stick position,
(hence my answer) because the only other way to stop any jump is to switch
when you know the pitch curves of two different idle up modes are the same.
That's usually from 3/4 to full throttle, but it requires the fly to be
pretty sure where his stick is at all times and some don't know where it is
ANY of the time:-)



--
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

[david]

> > You want to be a little careful with that statement.-10 in a normal
curve
> is
> > quite likely to get a beginner into a landing just slightly below ground
> > level.
>
> No mention of learning to fly was made Steve, just how to stop the jump
when
> switching into ans out of Idle up, and there IS only one way to guarantee
it
> doesn't and that's to have the same pitch curve on all the modes. Now it's
> not what I'd recommend (but he didn't ask for recommendations of he BEST
way
> to go about setting up Idle-up modes, just how to stop it jumping)
>
> Also, one has to make the assumption that he means at any stick position,
> (hence my answer) because the only other way to stop any jump is to switch
> when you know the pitch curves of two different idle up modes are the
same.
> That's usually from 3/4 to full throttle, but it requires the fly to be
> pretty sure where his stick is at all times and some don't know where it
is
> ANY of the time:-)
>
>
>
> --
> Beav
>
> Beav, quite right, I didnt ask for the best way, just a preventative way.

However, since you mention it...what IS the "best" way of setting up the
various curves?

I have rather deduced that the curves should be the same above the half
stick up position. In fact, to ensure linearity when inverted I have
assumed the inverted curve should be a mirror of the upright curve, at least
as a starting point.

Thanks

David

[Beav]

"david" <david_perry@btconnect.com> wrote in message
news:bbg3b7$7m9$1@sparta.btinternet.com...
>
>
> > > You want to be a little careful with that statement.-10 in a normal
> curve
> > is
> > > quite likely to get a beginner into a landing just slightly below
ground
> > > level.
> >
> > No mention of learning to fly was made Steve, just how to stop the jump
> when
> > switching into ans out of Idle up, and there IS only one way to
guarantee
> it
> > doesn't and that's to have the same pitch curve on all the modes. Now
it's
> > not what I'd recommend (but he didn't ask for recommendations of he BEST
> way
> > to go about setting up Idle-up modes, just how to stop it jumping)
> >
> > Also, one has to make the assumption that he means at any stick
position,
> > (hence my answer) because the only other way to stop any jump is to
switch
> > when you know the pitch curves of two different idle up modes are the
> same.
> > That's usually from 3/4 to full throttle, but it requires the fly to be
> > pretty sure where his stick is at all times and some don't know where it
> is
> > ANY of the time:-)
> >
> >
> >
> > --
> > Beav
> >
> > Beav, quite right, I didnt ask for the best way, just a preventative
way.
>
> However, since you mention it...what IS the "best" way of setting up the
> various curves?

Wiv a gaverna, gaverna:-)
>
> I have rather deduced that the curves should be the same above the half
> stick up position.

If you don't intend flying around upside down or doing the "3D" stuff, then
your deduction is pretty good, but even then, to ensure no jump between
"Normal" and the first of your "Idle-ups" there's a LOT of pissing about
with the throttle curve needed. Why??

Well let's imagine if you will that at your current half stick up position
in "Normal" you have 5 degrees pitch which is good for hovering. This will
require around 35 - 50% throttle opening (depending on how much grunt your
motor has) which is also good, but both are pretty useless for Idle up 1
where the pitch curve is stretched and lowered. We normally run slightly
less top end pitch in Idle up modes so the engine can still drive the blades
when full cyclic deflections are being used for whirling the heli around,
but this requires some more fiddling around at the mid stick position.

For your first Idle up setting if you reduce the pitch at the half stick up
position you HAVE to increase the throttle and speed everything up to
compensate for the loss of lift caused by the pitch reduction. If you DON'T
touch the throttle curve, then the heli drops when you switch into Idle up.
If you get the throttle increase and the pitch decrease perfectly matched,
there's no jump, but although I've seen it come close, I've yet to see it
happen perfectly out here in the real world. This is why I said using the
same pitch curves is the ONLY way to get a guaranteed stepless transition
between modes, because there's then no difference and hence no step.

In fact, to ensure linearity when inverted I have
> assumed the inverted curve should be a mirror of the upright curve, at
least
> as a starting point.

As far as pitch is concerned, (and inverted everything) a -9/+9 is what you
want, with zero degrees at the half stick up position, but that's just the
pitch curve, and the throttle curve has to match up too, which means the
throttle at mid stick will be roughly 30 - 35% open as a maximum. Not much
throttle is needed at zero degrees pitch as you'll probably notice when the
heli's sat on the ground revving it's tits off with the throttle barely
cracked open and the blades at zero (or even one or two degrees pos pitch)
in "Normal" mode.

So if you look at the varying amounts of pitch and the varying power
requirements FOR those pitch loadings, you'll see that there's VERY little
chance of switching from one mode to another without a hop skip or jump
unless you switch at the one stick position where things are all the same.
That, btw is just about full throttle, but again, only if the maximum pitch
is the same in all modes and lots of people don't have that, prefering less
pitch in the idle up's than in normal and more pitch in hold than in ANY of
the other modes.

Now the BEST way to fly is the simplest. Get a governor and (apart from T.
Hold) set all your maximum pitch points the same (around 9 degrees) set all
your bottom end pitches as you want them and "draw" a straight line between
the two points.

Set the speed on the governor, select the pitch range you want before you
take off, then fly. When you've FINISHED flying, come out of idle up and
stop the motor:-)

Failing buying a gov and using it like I just said, switch beween modes ONLY
above 3/4 throttle and preferable while the heli's climbing out.


--
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

[Chopper]

"Beav" <beavis.original@ntloxoworld.com> wrote in message
news:1AFCa.1019363$CK1.154308@news.easynews.com...
>
> "Chopper" <chopper@remove.blueyonder.co.uk> wrote in message
> news:lwsCa.3387$bZ3.21912728@news-text.cableinet.net...
> > Er Beav,
> > You want to be a little careful with that statement.-10 in a normal
curve
> is
> > quite likely to get a beginner into a landing just slightly below ground
> > level.
>
> No mention of learning to fly was made Steve, just how to stop the jump
when
> switching into ans out of Idle up, and there IS only one way to guarantee
it
> doesn't and that's to have the same pitch curve on all the modes. Now it's
> not what I'd recommend (but he didn't ask for recommendations of he BEST
way
> to go about setting up Idle-up modes, just how to stop it jumping)

No mention needed to be made, Beav, read the question, Quote "Just trying to
create my very first idle-up curve " If that doesn't smack of BEGINNER then
I don't know what does. Please remember beginners don't always know what
they want or need. Recommending all curves should be the same as his idle up
curve at -10 to +10 would certainly make me a little edgy. I guess you don't
fly with him so it doesn't concern you about the safety aspect!


> Also, one has to make the assumption that he means at any stick position,
> (hence my answer) because the only other way to stop any jump is to switch
> when you know the pitch curves of two different idle up modes are the
same.
> That's usually from 3/4 to full throttle, but it requires the fly to be
> pretty sure where his stick is at all times and some don't know where it
is
> ANY of the time:-)
>

> Beav

OK if you want to be pedantic, any stick position, though most unlikely.
Most people would switch idleups from a steady hover or in a climb. so
anywhere above half stick only needs to be the same.

Regards Steve