Resetting Winter Vario to Zero?

To give you an update on my process and success.

I used nail polish. On the Winter there is a cover (with the model and
serial number) which can be swung out of the way after loosing a screw.
I put the nail polish under that. The reasoning was that 1) the cover
will hide the polish and 2) placing a weight closer to the center
requires more weight to do the job (shorter moment arm). Thus, I have
more control over what I am doing.

It did take several coats as each coat dries and looses weight. The
trick was to determine if what I added was correct. I did the
following;

1) Added some nail polish with a toothpick to make the needle go to
zero.
2) CAREFULLY blow into the static and/or TE probe line fittings to
reset the needle.
NEVER BLOW DIRECTLY INTO THE INSTRUMENT as this is a very delicate
instrument. What I did was hold the vario facing me, then cupped my
hand behind the vario, the GENTLY blew into my hand. This deflected a
bit of air into the probe line fitting and deflected the needle. Hold
the vario as it will be in flight, face held vertical.
3) Let the nail polish dry and use step 2 again to see if the needle
rests at zero.
4) Repeat these steps as necessary.

Good luck.

- John

Hi Todd - I'm sure that practice makes perfect and after
3 times you're getting pretty good at fiddling the zero
on your Winter vario - but have you considered that
there might be a better way ?
http://www.ilec-gmbh.com/sb9.htm
Really !
Best Regards, Dave "YO"

T o d d P a t t i s t wrote:
"ContestID67" wrote:
tool to remove the ring holding the glass to the front.

I found some scrap aluminum that was as thin as the slot in the ring.
A steel ruler would work also but the aluminum is softer and less
likely to mar the face of the vario.

My tool was made from an old hacksaw blade. Take a piece of
dowel (IIRC, I used 5/8"), as long as the diameter of the
glass, and make a cut into the dowel lengthwise (with the
blade still in the hacksaw). You make the cut directly in
towards the center of the dowel, with the blade held
parallel to the dowel, cutting in along the radius until
you're halfway into the dowel. (If you finished this cut
the dowel would be split lengthwise.) Then remove and break
the blade, stick the toothed edge of the broken blade piece
into the slot you cut in the dowel. The dowel makes a
handle that will hold the teeth of the blade piece securely
and the back edge of the blade forms the tool. The back
side of the blade on mine stuck out of the dowel about 1/4".
Grind the broken ends of the blade to exactly match the
diameter of the retaining ring/glass.

I tried aluminum, but it was too soft. I had no trouble
with marring the face.

PS, I've done this a total of three times on three varios,
first with nail polish, then epoxy, then the screw adjust.
They all worked.

--
T o d d P a t t i s t - "WH" Ventus C
(Remove DONTSPAMME from address to email reply.)

Glad we both have learned from experience ;-)
Hope to see you at the ridge one of these days
and say Hi to Karen,
Best Regards, Dave

PS: Do you remember the educational sessions
involving topping off the compass fluid and the one
with the Sage vario ? Now *those* were classics...

I have read the thread and I suggest that there is more than one factor
affecting the needle position at rest with the variometer mounted
ordinarily, say in an instrument panel.

The factors a
1. The state of balance of the needle about the pivot - as affected by
the balance state of the needle.
2. The influence of zero setting springs - as affected by the serated
ring exposed under the little cover at the vario face centre (as with Winter
varios).

When we find that the vario at rest has the needle away from zero (with
Winter variometers usually 0.5 to 1 kt up due loss of solvents from the
white paint, and with PZL ofen down due ?? to luminescent paint absoring and
holding moisture??), what result do we want from our efforts to correct it?
I would suggest we want the outcome to be that the vario needle at rest sits
at zero both with the vario in both upright and inverted (ie rolled 180
degrees about the needle shaft axis) positions.

At rest hold the vario upright and note the needle position, and then hold
it inverted and note the needle position. From that information you can get
an idea as to whether it is a problem of needle balance (1 above) or zero
setting (2 above), or a mix of the two. For example a needle out of balance
of + 1 knot upright will show -1 knot with vario inverted.

Mostly it is a matter of 1 above. In the case of 1, fixing it by using the
zero setting springs via the serated ring will zero the needle with
variometer upright but not inverted! If it is a needle balance problem then
you need to fix the needle balance, not alter the zeroing springs. If you
fix the needle balance, then the needle will not respond to accelerations
during pullups, gusts, etc which is a better outcome.

I use paint placed close to the needle pivot because so little is needed to
produce balance. I use a broken hacksaw blade ground to length (and using
the plain edge not the serrated edge) to engage the ring
and facilitate its removal and reinstallation. Rather than fit the blade
element to a piece of timber to create a tool, I put the blade element in a
bench vise and hold the vario down onto the blade element. Then you get
precise control of the undoing and particularly the doing up force/torque.

Don't give the job to your local club member-gorrilla!

I welcome any contribution to improving the understanding presented above.
Cheers

Roger Druce

"ContestID67" wrote in message
ups.com...
I have a Winter variometer that works great except that at rest it
reads high (+1.5). While that makes me feel good in flight, I'd rather
zero the thing out. The question is how to do this.

I have been told two different ways to do this;

1) Find the zero adjustment - I removed the face plate but cannot find
the adjustment. Any ideas?

2) One person mentioned that over time the needle looses weight.
Because these devices are so sensitive the needle reads high. The idea
then is to add back the lost weight. This person recommended a small
dab of finger nail polish.

The last choice is to send it back to the factory which I would rather
avoid.

Thanks.

I thought Dave Ellis founded Cambridge. Is there a history of Cambridge (or
a history of the makers of soaring instruments) available?

Ray Warshaw


"T o d d P a t t i s t" wrote in message
...
wrote:

PS: Do you remember the educational sessions
involving topping off the compass fluid and the one
with the Sage vario ? Now *those* were classics...

Yes. Do you remember the session by Raoulf Ismael (sp?),
founder of Cambridge, on the design of the first Cambridge
vario with the multiple thermistors in the flow channel? He
made it sound easy, but I spent a summer building my own and
trying to get it right. I've still got some of the
thermistor sensors I built.

--
T o d d P a t t i s t - "WH" Ventus C
(Remove DONTSPAMME from address to email reply.)

Raoulf Ismail was originally from the UK, and from Cambridge University in
the UK. For a short while he was a member of Lasham and the Surrey &
Hants. club before moving to the USA.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.


"T o d d P a t t i s t" wrote in message
...

"Raphael Warshaw" wrote:

I thought Dave Ellis founded Cambridge. Is there a history of Cambridge
(or
a history of the makers of soaring instruments) available?

I believe Dave Ellis bought the company from Raoulf. Raoulf
was at MIT (where Dave Nadler and I learned to fly), and
named it for Cambridge, Mass (where MIT is located).
--
T o d d P a t t i s t - "WH" Ventus C
(Remove DONTSPAMME from address to email reply.)

No, I don't know. I always thought it was for Cambridge U.K., but this
was just a guess on my part, I did not realise he also had a connection with
Cambridge USA. Perhaps it was both.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.


"T o d d P a t t i s t" wrote in message
news
"W.J. \(Bill\) Dean \(U.K.\)."
wrote:

Raoulf Ismail was originally from the UK, and from Cambridge University in
the UK. For a short while he was a member of Lasham and the Surrey &
Hants. club before moving to the USA.

Do you know if the name was selected for Cambridge
University/UK?

--
T o d d P a t t i s t - "WH" Ventus C
(Remove DONTSPAMME from address to email reply.)