3/5 different questions

[Werner F.E.Goldbaum]

Hallo,

first no actual question: Am I the only one one who builds the helicopter
after a crash exactly the same as before, but it's always "slightly"
different?

Now a question (especially for Beav?) which I'd like to undersand
physically: Adjusting the Rossi of my repaired Kobold it ran fine in idle
and turning up. But then, before lifting off it got very rich and nearly
died. Well I got rid of it by leaning up _both_ needles. Now all is ok, but
my _feeling_ is, it's too lean when idling. (I do like rich running motors.)
The question: I think it got too rich, when the idle-needle went free. But
then it should be enough to turn in the main-needle. Why isn't it?

Second question, same Kobold: In "stormy" wheather the tail begins wagging
_very_ uncomfortable in right curves. In all other states the heli flies
smooth as I like it. (Well I'm just a sunday-pilot and no 3D-enthusiast...)
What's the matter in that right curves?

The third: Some time ago a guy wrote how he set up the high tanks on a
Vario-Bell 47G an was very satisfied how he did it. He even send me some
pictures, I was sure I saved them, but... (please do again (no, Sam is not
his name...))

The question: I love uniflow tanks on my helis. So I tried it with two tanks
in carb-altetudes. Both connectet with clunks on muffler-pressure, both with
clunks to the carb. both with seperate tubes for air when being fuel-filled
and shut for running. The Rossi runs both tanks empty to their last drop. So
I _should_ be satisfied. BUT always the right tank gets empty first, while
the left one is quarter-filled. THAT's what I do not understand! I am sure
both tanks should have the same fuel-altitude all the time...

Well, thanks to all who read that mail, because as always: please excuse,
I'm not a native english writer...
Yours, Werner

[Rhodesst]

Hi Werner,

>Am I the only one one who builds the helicopter
>after a crash exactly the same as before, but it's always "slightly"
>different?

Rebuilding a model and getting it setup "exactly" as it was before the rebuild
is next to impossible. The more experience you get, the closer you'll be able
to come but even then, there will always be some adjustments to make.

<skipping questions aimed at Beav> :-)

>
>Well, thanks to all who read that mail, because as always: please excuse,
>I'm not a native english writer...
>Yours, Werner

English may not be your first language but you're doing better than a lot of
people I've seen on the Internet that don't have that excuse.

Good luck & Fly Safe,
Steve R.

[Beav]

"Werner F.E.Goldbaum" <WFEGb@t-online.de> wrote in message
news:bit45v$b7n$01$1@news.t-online.com...
> Hallo,
>
> first no actual question: Am I the only one one who builds the helicopter
> after a crash exactly the same as before, but it's always "slightly"
> different?

It's probably one of life's mysteries Werner, but no, you're not the only
one. I do it all the time (re-building machines I've set up for others after
they've been "decked") and it's always necessary to spend some time
trimming/adjusting/yweaking, in order to get the heli to fly like it did
before the smack. We can get CLOSE, but getting it identical is difficult.
Even when you build two heli's "side by side" using all the same gear, they
don't fly the same "off the board" so even then, a fair amount of tweaking
is needed.
>
> Now a question (especially for Beav?) which I'd like to undersand
> physically: Adjusting the Rossi of my repaired Kobold it ran fine in idle
> and turning up. But then, before lifting off it got very rich and nearly
> died. Well I got rid of it by leaning up _both_ needles. Now all is ok,
but
> my _feeling_ is, it's too lean when idling. (I do like rich running
motors.)

It's an ABC and it SHOULDN'T be run rich at any point. When an ABC runs
rich, (after running at optimum) the liner cools faster than the piston (and
shrinks faster) so it CAN "grab" the piston causing it to sieze, so don't
get too hell bent on getting the idle too rich.

> The question: I think it got too rich, when the idle-needle went free. But
> then it should be enough to turn in the main-needle. Why isn't it?

If the "problem" came only after an idle mixture adjustment was made (by
accident, on purpose, or by act of God) then it should only be the idel
screw that needs attention. The thing about Rossi's is the idle mixture
should only be touched once the MAIN needle has been optimised and the
engine is HOT. Most people attempt to adjust the idle end of things first,
because they can do that while the heli is sat on the ground "idling", but
of they do that, then as the engine DOES get hot, the idle mixture needs
changing. To get the whole mixture correct (for any engine) it's a good idea
to use some form of equipment that allows the engine to be adjusted while
it's running at full throttle AND at idle. I use a tall stand so I can get
underneath the heli and adjust things "on the fly", but "Headloaders" allow
pretty much the same thing if the heli is clamped to a "Workmate" type of
thing.

The "trick" is to get the engine HOT, adjust the main needle for max revs
(with the blades on and running max pitch, so make sure the heli is SOLIDLY
mounted and can't fly off), then come to idle and make adjustments SLOWLY to
the idle mixture. Then go back to full throttle and "tweak" the main needle,
and back again to idle. Now it's down to TINY adjustments of either needle
(although it's usually the idle needle) to get a smooth transition from idle
to half throttle to full throtle and you're done.

>
> Second question, same Kobold: In "stormy" wheather the tail begins wagging
> _very_ uncomfortable in right curves. In all other states the heli flies
> smooth as I like it. (Well I'm just a sunday-pilot and no
3D-enthusiast...)
> What's the matter in that right curves?

Well the tail is running less pitch in a right turn (being a cack handed
Vario:-) and torque is helping the turn, so a slight reduction in gain on
the rudder channel will stop it. Either that or a SLIGHT reduction in blade
length.

If the heli doesn't rotate fast enough with either of those reductions, an
increase in the rudder ATV will soon see thngs back on track. Rudder ATV
increases the speed of ratation and "gyyo" ATV (I have all mine on channel
5) controls the gain or "anti-wag".

>
> The third: Some time ago a guy wrote how he set up the high tanks on a
> Vario-Bell 47G an was very satisfied how he did it. He even send me some
> pictures, I was sure I saved them, but... (please do again (no, Sam is
not
> his name...))
>
> The question: I love uniflow tanks on my helis. So I tried it with two
tanks
> in carb-altetudes. Both connectet with clunks on muffler-pressure, both
with
> clunks to the carb. both with seperate tubes for air when being
fuel-filled
> and shut for running. The Rossi runs both tanks empty to their last drop.
So
> I _should_ be satisfied. BUT always the right tank gets empty first, while
> the left one is quarter-filled. THAT's what I do not understand! I am sure
> both tanks should have the same fuel-altitude all the time...

You've got me on that one. I've never run twin tanks using a unli-flow
system. In fact I've never run twin tanks on anything.

>
> Well, thanks to all who read that mail, because as always: please excuse,
> I'm not a native english writer...

Better than my German by a LOOOOOONG way!! I spent a few weeks in the
company of a German guy a few years ago and he couldn't speak ANY English,
and I couldn't do much better in German, but we both spoke Swedish, so we
talked the whole time in Swedish. It tickled a few Swede's that their
language was the "International Langusge" of the week though:-)



--
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

[Werner F.E.Goldbaum]

Hallo Beav,

thank you very much for your almost complete answers!

> It's an ABC and it SHOULDN'T be run rich at any point. When an ABC runs
> rich, (after running at optimum) the liner cools faster than the piston
(and
> shrinks faster) so it CAN "grab" the piston causing it to sieze, so don't
> get too hell bent on getting the idle too rich.

I did not know this and think have to be lucky never had such a problem with
my Rossis...

> ...The thing about Rossi's is the idle mixture
> should only be touched once the MAIN needle has been optimised and the
> engine is HOT. Most people attempt to adjust the idle end of things first,
> because they can do that while the heli is sat on the ground "idling", but
> of they do that, then as the engine DOES get hot, the idle mixture needs
> changing.

Yes I think this has been the problem. But I've been pampered by all my
Rossis, because the idle screw had never been to be more adjustest than
a quarter turn (and this whas "very much" even after running in). All
adjustments I had to do at full throttle. This time I had to start with the
tip: Idle
needle full out, then two turns in. full needle full in then two turns out.
And then there was some more "uncomfortable" tweaking needed...

> To get the whole mixture correct (for any engine) it's a good idea
> to use some form of equipment that allows the engine to be adjusted while
> it's running at full throttle AND at idle. I use a tall stand so I can get
> underneath the heli and adjust things "on the fly", but "Headloaders"
allow
> pretty much the same thing if the heli is clamped to a "Workmate" type of
> thing.

May be we should think about this in our club. Thanks for the tip. I think
some guys will tell me: I've told it so often, but novbody listened....

> The "trick" is to get the engine HOT, adjust the main needle for max revs
> (with the blades on and running max pitch, so make sure the heli is
SOLIDLY
> mounted and can't fly off), then come to idle and make adjustments SLOWLY
to
> the idle mixture. Then go back to full throttle and "tweak" the main
needle,
> and back again to idle. Now it's down to TINY adjustments of either needle
> (although it's usually the idle needle) to get a smooth transition from
idle
> to half throttle to full throtle and you're done.

Yes that was the prodedure I had to go through... more or less in try and
error with short flights between...


> Well the tail is running less pitch in a right turn (being a cack handed
> Vario:-) and torque is helping the turn, so a slight reduction in gain on
> the rudder channel will stop it. Either that or a SLIGHT reduction in
blade
> length.

I'll try the first first...

> If the heli doesn't rotate fast enough with either of those reductions, an
> increase in the rudder ATV will soon see thngs back on track. Rudder ATV
> increases the speed of ratation and "gyyo" ATV (I have all mine on channel
> 5) controls the gain or "anti-wag".

That should not run in a problem, but fine to have a way out if it does...

> You've got me on that one. I've never run twin tanks using a unli-flow
> system. In fact I've never run twin tanks on anything.

Well Beav, I'm VERY proud of myself, that THIS was even possible ,-)))

> Better than my German by a LOOOOOONG way!! I spent a few weeks in the
> company of a German guy a few years ago and he couldn't speak ANY English,
> and I couldn't do much better in German, but we both spoke Swedish, so we
> talked the whole time in Swedish. It tickled a few Swede's that their
> language was the "International Langusge" of the week though:-)

Sorry, but I really don't know how to write a single word in Swedish!

Thank you once more for your answers they are "MUECKE BRO" (???)

Werner

Disclaimer: Please excuse my English, but I'm no native English writer...

PS: And if the guy who was satisfied by his tank arrangement for the
high-tanks on the Vario Bell 47G is still reading, it would be very kind, if
he would give me advice in it. (One more...)