refinishing Ventus 2cm- wing profile

Ken,

Suggestion for you, start off by measuring the max thickness of each
wing at say the root and 1meter increments and compare the two
measurements. With that info in front of you, you will discover that
gliders wings are not precision manufactured. The amount of work and
money it would take to make two identical and correct to a speciific
airfoil shape may be more than realistic. I would devote my time to
making the leading edge correct and the remainder of the wing fair.

Bob Fidler "F1"


On Nov 1, 5:25*am, BruceGreeff wrote:
The joys of ever advancing computer computational power.
As things have become possible to calculate so the glider wings get more
complex. The current crop of 18m ships are currently approaching thirty
profiles over the ~8.7m of wing... To

They generally blend the transition from one to the next, but you
certainly can't measure a station and extrapolate further out or inboard.

Yes they are not all made in CNC machined steel female mounds like the
JS1 - and even there I am sure there is manufacturing variation, but you
would have to think carefully before re-profiling significantly. Easy to
disimprove things.

On 2011/10/31 4:51 PM, Rick Walters wrote:









On Oct 30, 3:40 pm, wrote:
Can anyone help with the wing profile data for a Ventus 2cm? I need
the numerical data and if possible someone who could make templates on
a CNC. I have contacted US dealer with no response. *Ken

Ken

SH does not publish their airfoil data, or glide polars for that
matter.
The Ventus airfoil has changed in subtle ways since the 1981 a/b model
introduction.
The most notable changes have been a sharper leading edge and a
thinner profile near the wingtip,
which showed up on the V2a/b and C models. Take Bob's advice and sand,
smooth, and polish.

Rick

--
Bruce Greeff
T59D #1771 & Std Cirrus #57

On Nov 2, 11:46*am, Robert Fidler wrote:
Ken,

Suggestion for you, start off by measuring the max thickness of each
wing at say the root and 1meter increments and compare the two
measurements. With that info in front of you, you will discover that
gliders wings are not precision manufactured. The amount of work and
money it would take to make two identical and correct to a speciific
airfoil shape may be more than realistic. I would devote my time to
making the leading edge correct and the remainder of the wing fair.

Bob Fidler "F1"

On Nov 1, 5:25*am, BruceGreeff wrote:







The joys of ever advancing computer computational power.
As things have become possible to calculate so the glider wings get more
complex. The current crop of 18m ships are currently approaching thirty
profiles over the ~8.7m of wing... To

They generally blend the transition from one to the next, but you
certainly can't measure a station and extrapolate further out or inboard.

Yes they are not all made in CNC machined steel female mounds like the
JS1 - and even there I am sure there is manufacturing variation, but you
would have to think carefully before re-profiling significantly. Easy to
disimprove things.

On 2011/10/31 4:51 PM, Rick Walters wrote:

On Oct 30, 3:40 pm, wrote:
Can anyone help with the wing profile data for a Ventus 2cm? I need
the numerical data and if possible someone who could make templates on
a CNC. I have contacted US dealer with no response. *Ken

Ken

SH does not publish their airfoil data, or glide polars for that
matter.
The Ventus airfoil has changed in subtle ways since the 1981 a/b model
introduction.
The most notable changes have been a sharper leading edge and a
thinner profile near the wingtip,
which showed up on the V2a/b and C models. Take Bob's advice and sand,
smooth, and polish.

Rick

--
Bruce Greeff
T59D #1771 & Std Cirrus #57

Better use the time and $$ to fly and train rather than trying to
achieve the utmost accuracy. One wrong thermal and you are a behind.

On 11/2/2011 9:43 AM, wladkummer76 wrote:


Better use the time and $$ to fly and train rather than trying to
achieve the utmost accuracy. One wrong thermal and you are a behind.

You can do both: sand and paint in the Winter, and you can have a glider
that climbs and glides better all the time. Fly in the summer, and learn
to choose better thermals. If you do the work yourself, I don't think
the cost is very high, and you'll get some of that back if you sell it,
and enjoy looking at it and wiping down in the meantime.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

On Oct 30, 6:40*pm, wrote:
Can anyone help with the wing profile data for a Ventus 2cm? I need
the numerical data and if possible someone who could make templates on
a CNC. I have contacted US dealer with no response. *Ken

I'm curious as to why you think you want/need to do this.
The most it is likely to need is a bit of fill and smoothing of shrink
areas.
From my experience, if you aren't in the top 10 at the Nationals, you
are wasting your time and money.
Airfoil coordinates are proprietary and are not generally made
available to customers or others.
If you haven't done this before, you are more likely to make the
glider worse instead of better.
FWIW
UH

On Nov 3, 8:29*am, wrote:
On Oct 30, 6:40*pm, wrote:

Can anyone help with the wing profile data for a Ventus 2cm? I need
the numerical data and if possible someone who could make templates on
a CNC. I have contacted US dealer with no response. *Ken

I'm curious as to why you think you want/need to do this.
The most it is likely to need is a bit of fill and smoothing of shrink
areas.
From my experience, if you aren't in the top 10 at the Nationals, you
are wasting your time and money.
Airfoil coordinates are proprietary and are not generally made
available to customers or others.
If you haven't done this before, you are more likely to make the
glider worse instead of better.
FWIW
UH

To satisfy your curiosity I will enlighten to my reasons for
refinishing the Ventus. I SH gel-coat does not hold up well in
Florida (or anywhere else where the sun shines). And even tho
presently I'am not in the top 10 at the National doesn't mean I don't
want to fly a sailplane that performs like a contender. The gel-coat
is crazed and needs redone. Its A lot of work so I want to do the best
I can.

On Nov 3, 9:40*pm, wrote:
On Nov 3, 8:29*am, wrote:





On Oct 30, 6:40*pm, wrote:

Can anyone help with the wing profile data for a Ventus 2cm? I need
the numerical data and if possible someone who could make templates on
a CNC. I have contacted US dealer with no response. *Ken

I'm curious as to why you think you want/need to do this.
The most it is likely to need is a bit of fill and smoothing of shrink
areas.
From my experience, if you aren't in the top 10 at the Nationals, you
are wasting your time and money.
Airfoil coordinates are proprietary and are not generally made
available to customers or others.
If you haven't done this before, you are more likely to make the
glider worse instead of better.
FWIW
UH

To satisfy your curiosity I will enlighten to my reasons for
refinishing the Ventus. *I SH gel-coat does not hold up well in
Florida (or anywhere else where the sun shines). And even tho
presently I'am not in the top 10 at the National doesn't mean I don't
want to fly a sailplane that performs like a contender. The gel-coat
is crazed and needs redone. Its A lot of work so I want to do the best
I can.- Hide quoted text -

- Show quoted text -

So this is a "normal" mid life refinish. No templates needed for this
if care is taken in sanding. If you are concerned with holding shape,
pull templates off wings before refinishing. First 6 inches is
plenty.
Cut 1/2 think MDF to rough profile. Wax surface. Mix up body filler
and spread on template. Slap in place and hold till cured.
A template every 2 ft is enough.
When sanding, only hand sand on leading edge area with block about 11
inches long.
Beware, this is far more work than you think.
BTDT too many times
Good luck
UH

On Nov 4, 1:42*pm, wrote:
On Nov 3, 9:40*pm, wrote:





On Nov 3, 8:29*am, wrote:

On Oct 30, 6:40*pm, wrote:

Can anyone help with the wing profile data for a Ventus 2cm? I need
the numerical data and if possible someone who could make templates on
a CNC. I have contacted US dealer with no response. *Ken

I'm curious as to why you think you want/need to do this.
The most it is likely to need is a bit of fill and smoothing of shrink
areas.
From my experience, if you aren't in the top 10 at the Nationals, you
are wasting your time and money.
Airfoil coordinates are proprietary and are not generally made
available to customers or others.
If you haven't done this before, you are more likely to make the
glider worse instead of better.
FWIW
UH

To satisfy your curiosity I will enlighten to my reasons for
refinishing the Ventus. *I SH gel-coat does not hold up well in
Florida (or anywhere else where the sun shines). And even tho
presently I'am not in the top 10 at the National doesn't mean I don't
want to fly a sailplane that performs like a contender. The gel-coat
is crazed and needs redone. Its A lot of work so I want to do the best
I can.- Hide quoted text -

- Show quoted text -

So this is a "normal" mid life refinish. No templates needed for this
if care is taken in sanding. If you are concerned with holding shape,
pull templates off wings before refinishing. First 6 inches is
plenty.
Cut 1/2 think MDF to rough profile. Wax surface. Mix up body filler
and spread on template. Slap in place and hold till cured.
A template every 2 ft is enough.
When sanding, only hand sand on leading edge area with block about 11
inches long.
Beware, this is far more work than you think.
BTDT too many times
Good luck
UH- Hide quoted text -

- Show quoted text -

Heinz's talked to the factory today, bottom line ,they are not willing
to give up the data. I,ve been making templates off the orignal finish
every 2 ft. and will use plan B. It's not more work than I think,it's
more work than I would like to do.

On Nov 4, 9:07*pm, Janet Goshorn wrote:
On Nov 4, 1:42*pm, wrote:









On Nov 3, 9:40*pm, wrote:

On Nov 3, 8:29*am, wrote:

On Oct 30, 6:40*pm, wrote:

Can anyone help with the wing profile data for a Ventus 2cm? I need
the numerical data and if possible someone who could make templates on
a CNC. I have contacted US dealer with no response. *Ken

I'm curious as to why you think you want/need to do this.
The most it is likely to need is a bit of fill and smoothing of shrink
areas.
From my experience, if you aren't in the top 10 at the Nationals, you
are wasting your time and money.
Airfoil coordinates are proprietary and are not generally made
available to customers or others.
If you haven't done this before, you are more likely to make the
glider worse instead of better.
FWIW
UH

To satisfy your curiosity I will enlighten to my reasons for
refinishing the Ventus. *I SH gel-coat does not hold up well in
Florida (or anywhere else where the sun shines). And even tho
presently I'am not in the top 10 at the National doesn't mean I don't
want to fly a sailplane that performs like a contender. The gel-coat
is crazed and needs redone. Its A lot of work so I want to do the best
I can.- Hide quoted text -

- Show quoted text -

So this is a "normal" mid life refinish. No templates needed for this
if care is taken in sanding. If you are concerned with holding shape,
pull templates off wings before refinishing. First 6 inches is
plenty.
Cut 1/2 think MDF to rough profile. Wax surface. Mix up body filler
and spread on template. Slap in place and hold till cured.
A template every 2 ft is enough.
When sanding, only hand sand on leading edge area with block about 11
inches long.
Beware, this is far more work than you think.
BTDT too many times
Good luck
UH- Hide quoted text -

- Show quoted text -

Heinz's talked to the factory today, bottom line ,they are not willing
to give up the data. I,ve been making templates off the orignal finish
every 2 ft. and will use plan B. It's not more work than I think,it's
more work than I would like to do.

And be sure to seal it tight and put the the CG exactly the way it
behaves the best (usually a personal taste, but does make a difference
in thermals)

On Nov 3, 6:40*pm, wrote:

To satisfy your curiosity I will enlighten to my reasons for
refinishing the Ventus. *I SH gel-coat does not hold up well in
Florida (or anywhere else where the sun shines). And even tho
presently I'am not in the top 10 at the National doesn't mean I don't
want to fly a sailplane that performs like a contender. The gel-coat
is crazed and needs redone. Its A lot of work so I want to do the best
I can.

If you have crazed gelcoat, that is obviously not a good thing.

But making CNC templates for some mythical reference profile, and then
adding a bunch of filler and work to make your wings match it, will
likely introduce more problems than it solves. Your best bet is to
profile only the first few inches of leading edge, and for the rest of
it just concentrate on getting the waviness down to around .002". And
given a choice between those, I'd ditch the profiling and concentrate
on the waviness.

I've done template checks on a variety of sailplanes, and I have
stopped being surprised at how often the left wing profile has
substantial variations from that of the right wing. And this isn't on
dogmeat gliders, these are nationals-winning machines that go like
stink and fly straight as arrows. The takeaway there is that absolute
fidelity to profile is way down on the list of things you need. Much
higher on the list is lack of waviness that prematurely trips laminar
flow .

Thanks, Bob K.
www.hpaircraft.com/hp-24
(also search Facebook for "HP-24")