Mechanical Vario

The Crossfell did work OK but the scaling was off, like it
never ever
showed more than 1 m/s

The Crossfell in my RS-15 (glider now sold) gave 32 years
of reliable service. The Crossfell was retired in perfect
working condition. There was a rotary switch
that changed the scale to 3x or 5x, I forget exactly which.
Yours may have been set or stuck in expanded scale.

Btw, mine read in feet per second. My mechanical backup was in
meters per second.
Meanwhile, over the radio everyone was talking about how many
knots of lift they were in. ;-)

and it would show down when I was going up.

Yeah, that's an indication that something was amiss.

--
Regards,
Doug


--
Posted via a free Usenet account from http://www.teranews.com

Jeff Runciman wrote:
This question was posted earlier but I was hoping for
a few more responses.

Do I put a mechanical vario or do I save space on the
panel.

Would love to hear what people have in their panel.

Jeff




go for the electric backup that has it's own battery or internal
rechargable battery. No sense being w/o an audio.

I've always had a backup vario. Some were electric, others mechanical.
Some were completely separate (power, static, TE, pitot), others had a
common point of failure (usually the TE probe and/or electrical bus/
common battery selector switch). I'm not sure there's a perfect answer
although the small, self contained electonic vario with audio/averager
sounds good if you could connect it to a separate TE source.

[On that note, I had a running correspondence with one of the major
vario/flight computer systems last year about offering electronic TE
as a backup option. His contention was that it didn't work as well as
a good TE probe. My point was that if the probe failed (it's happens),
I'd like to have a backup TE vario. We never came to a common
understanding although I think one of the major manufacturers offers
something like this.]

Get something good enough to fly a contest with, not just to limp
home. That way you'll be familiar with it when your primary vario does
fail.

I've had batteries fail with little warning (yes, I have a backup).
The panel-mounted fuse holder came loose at one national contest and
provided intermittant power. One mechanical vario failed suddenly. And
the pressure capsule in my ASI failed at another national contest
which not only gave me no airspeed info but also removed the netto and
speed-to-fly info from my primary vario/flight computer.

If you fly long enough, something will fail. Provide redundancy with
as few common points of failure as possible, then go fly.

Chip Bearden
ASW 24 "JB"
USA

Good point about TE probe failure. I've been thinking about adding a Dick
Johnson midship probe. I'll keep my tail mounted probe as a backup.

About battery failure. I've never known of a failure except in very new
(rare) or very old batteries. I had a conversation with a pilot I saw with
three huge batteries under his arm walking toward his glider.
Q. Why so many?
A. They might fail.
Q. How old are they?
A. I dunno, they came with the glider
Q. How long have you owned the glider?
A. 10 years.

Sealed Lead Acid rechargables are really only reliable for three years
whether on the shelf or in use. I start with a fresh one every two years.
I also go through the wiring at least twice a season. So far, no failures.

Bill D


"Chip Bearden" wrote in message
ups.com...
I've always had a backup vario. Some were electric, others mechanical.
Some were completely separate (power, static, TE, pitot), others had a
common point of failure (usually the TE probe and/or electrical bus/
common battery selector switch). I'm not sure there's a perfect answer
although the small, self contained electonic vario with audio/averager
sounds good if you could connect it to a separate TE source.

[On that note, I had a running correspondence with one of the major
vario/flight computer systems last year about offering electronic TE
as a backup option. His contention was that it didn't work as well as
a good TE probe. My point was that if the probe failed (it's happens),
I'd like to have a backup TE vario. We never came to a common
understanding although I think one of the major manufacturers offers
something like this.]

Get something good enough to fly a contest with, not just to limp
home. That way you'll be familiar with it when your primary vario does
fail.

I've had batteries fail with little warning (yes, I have a backup).
The panel-mounted fuse holder came loose at one national contest and
provided intermittant power. One mechanical vario failed suddenly. And
the pressure capsule in my ASI failed at another national contest
which not only gave me no airspeed info but also removed the netto and
speed-to-fly info from my primary vario/flight computer.

If you fly long enough, something will fail. Provide redundancy with
as few common points of failure as possible, then go fly.

Chip Bearden
ASW 24 "JB"
USA

At 22:30 23 September 2007, Dan G wrote:
If my primary (electric audio) vario failed it most
likely be because
of a general power failure, which would have also have
left me without
radio, GPS and logger. If I did want to use a mechanical
vario, I'd
have to go 'heads down', which is something I just
won't do. I'd fly
home via the seat of my pants.

So, no mechanical vario here.

The words of a K8 flying stroker! Get a life - any
reasonably experienced pilot is perfectly safe with
the odd glance at a mechanical vario!

My advice would be to have at least one back-up vario
either mechanical or electrical. (I fly with Cambridge,
so I have a backup everything, plus a mechanical).
As always buy the best you can afford. A 302 is a pretty
good vario and only fills one 57mm hole, and then you
get a back-up GPS as well. If you are lucky enough
to be able to afford this, then its an option.

I agree with Kirk as far as the 'useful' info is concerened.
I have a Sage mechanical (thanks kirk) as the mechanical
backup to my SN10. I find that the Mechanical gives
me a good indication of whats happening outside with
air as it is compensated and gust filtered very well,
and the SN10 gives me a very fast response and allows
me to center quicker and stay there. In other words
when I hear an audio response to lift while cruising
I slow down and glance at the sage and determine whether
or not it is worth making a turn or moving on. The
Sage gives me a better avgerage of what I just flew
into than the SN10. The SN10 gives me a instant responce
that is to short of a time frame to tell if it is
a gust or continued lift. I would like to have a 9volt
audio back up connected to the sage in case of power
failure, but not enough room in the panel or is
there?


At 14:54 25 September 2007, Kirk.Stant wrote:

Which leads to an interesting point - it isn't so much
the actual
reading on the vario that is important, as the ease
of using the datapresented to climb more efficiently.
So the hole 'accuracy' argument is a bit ridiculous.
If it is really sensitive, it overreacts to gusts.
If it is highly damped, it's an averager. That's why
I want the audio, to let my brain (and butt) figure
out the gusts from the surges and center accordingly.
Tough while staring at a needle on a mechanical that
hasn't been looked at much before, after the needle
on the ubervario MK 69 falls off...

Once upon a time, there was such a thing----an electric audio attachment for
a pneumatic/mechanical vario. Or perhaps it was just plumbed in the
pneumatic lines. Adjustable for volume and threshold. It was a little black
box that didn't need to be in the panel at all. Perhaps you can find a used
one somewhere.
--
Hartley Falbaum

"Cliff Hilty" wrote in message
...
I agree with Kirk as far as the 'useful' info is concerened.
I have a Sage mechanical (thanks kirk) as the mechanical
backup to my SN10. I find that the Mechanical gives
me a good indication of whats happening outside with
air as it is compensated and gust filtered very well,
and the SN10 gives me a very fast response and allows
me to center quicker and stay there. In other words
when I hear an audio response to lift while cruising
I slow down and glance at the sage and determine whether
or not it is worth making a turn or moving on. The
Sage gives me a better avgerage of what I just flew
into than the SN10. The SN10 gives me a instant responce
that is to short of a time frame to tell if it is
a gust or continued lift. I would like to have a 9volt
audio back up connected to the sage in case of power
failure, but not enough room in the panel or is
there?


At 14:54 25 September 2007, Kirk.Stant wrote:

Which leads to an interesting point - it isn't so much
the actual
reading on the vario that is important, as the ease
of using the datapresented to climb more efficiently.
So the hole 'accuracy' argument is a bit ridiculous.
If it is really sensitive, it overreacts to gusts.
If it is highly damped, it's an averager. That's why
I want the audio, to let my brain (and butt) figure
out the gusts from the surges and center accordingly.
Tough while staring at a needle on a mechanical that
hasn't been looked at much before, after the needle
on the ubervario MK 69 falls off...

On Sep 25, 1:12 pm, "HL Falbaum" wrote:
Once upon a time, there was such a thing----an electric audio attachment for
a pneumatic/mechanical vario. Or perhaps it was just plumbed in the
pneumatic lines. Adjustable for volume and threshold. It was a little black
box that didn't need to be in the panel at all. Perhaps you can find a used
one somewhere.

thats what i would really like.

On Sep 25, 4:51 pm, wrote:
thats what i would really like.

I think what you're looking for is a Piep audio. There were a lot of
them about in the 1960s and 1970s. Very simple and reliable. Two knobs
(volume and threshold), two hose connectors (static and capacity), and
a plug for +12DCV and ground. They have fairly low restriction, so you
can plub it in series with a mechanical vario without problem. They
seem to like a one-pint flask, but they're not particularly picky. I
had one for ten years and really liked it.

I bet if you ask around among the old-timers in your area you'll find
somebody with one in the bottom of a box of junk. It'll probably still
have the Graham Thompson sticker on it.

Thanks, Bob K.

On Sep 25, 8:16 pm, Bob Kuykendall wrote:
On Sep 25, 4:51 pm, wrote:

thats what i would really like.

I think what you're looking for is a Piep audio. There were a lot of
them about in the 1960s and 1970s. Very simple and reliable. Two knobs
(volume and threshold), two hose connectors (static and capacity), and
a plug for +12DCV and ground. They have fairly low restriction, so you
can plub it in series with a mechanical vario without problem. They
seem to like a one-pint flask, but they're not particularly picky. I
had one for ten years and really liked it.

I bet if you ask around among the old-timers in your area you'll find
somebody with one in the bottom of a box of junk. It'll probably still
have the Graham Thompson sticker on it.

Thanks, Bob K.

Yes, the Piep was a nice gadget. I also flew with one for many years--
it was my first audio vario--and liked it. When electric varios became
ubiquitous in the U.S. (mostly Cambridge in those days), we sold it.
If you can find a working one, it's a cheap, simple way to add audio
to most mechanical varios. IIRC, the current drain was very low, too.
This was back in the days when we all had Bayside BEI-990 radios and a
set of batteries (Everready 560?) needed charging only a few times a
season. That sounds crazy as I type this. Does anyone else remember if
this was true?

Chip Bearden
ASW 24 "JB"
USA