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air extractor for asw19 and asw20



 
 
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  #11  
Old October 18th 17, 12:33 AM posted to rec.aviation.soaring
[email protected]
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Posts: 69
Default air extractor for asw19 and asw20

I didn’t cut the holes, but mine has a fold down wood bulkhead with a pretty gap (about 1/2 inch) around the perimeter. That gap was large enough that I though I’d give it a try before cutting the holes. I was happy with the result, so I’ll probaby not cut the holes. The fiberglass bulkhead has a tighter fit, so you may ne d the holes.

John
Ads
  #12  
Old October 18th 17, 03:17 AM posted to rec.aviation.soaring
sisu1a
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Posts: 546
Default air extractor for asw19 and asw20

On Monday, October 16, 2017 at 8:03:30 PM UTC-7, JS wrote:
On Monday, October 16, 2017 at 6:47:55 PM UTC-7, wrote:
I just installed a very cool - pun intended - air extractor in my ASW19.. Its a nifty device that replaces that little hatch cover where the control connections are. My guess is that it was made on a 3D printer. Anyway, I couldn’t believe how well it worked and so I’m putting a shameless plug for that thing here. I got it from an outfit in the UK called LJ Panels. I don’t often get carried away raving things, but this one is the cats meow.


Is it anything like the ones that Paul Hanson sold years ago?
Jim


They are similar, but they adopted the dual 'louver' type outlet the Jonkers team came up with. No form on treatment on the interior. Te parts are laser sintered nylon so finish is quite rough (something between sandstone and wood) until primed/sanded, though some Polyprimer and sanding would make them really nice.

My guess is they work at least as well if not better due to having higher surface area with the double outlet even with the forward louver is partly blocked by the attach point, though likely to make a bit more noise with the air hitting the outlet without any organization taking place on the inside..

Wish I would have made my test pod to quantify this stuff, but never did though I do still make/sell the hatches I have been in fiberglass, prefinished with PCL 907 white to a #320 grit
  #13  
Old October 20th 17, 01:13 PM posted to rec.aviation.soaring
Dan Mockler
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Posts: 18
Default air extractor for asw19 and asw20

At 02:17 18 October 2017, sisu1a wrote:
On Monday, October 16, 2017 at 8:03:30 PM UTC-7, JS wrote:
On Monday, October 16, 2017 at 6:47:55 PM UTC-7,

wrot=
e:
I just installed a very cool - pun intended - air extractor in my

ASW19=
.. Its a nifty device that replaces that little hatch cover where the
contr=
ol connections are. My guess is that it was made on a 3D printer.
Anywa=
y, I couldn=E2=80=99t believe how well it worked and so I=E2=80=99m
putting=
a shameless plug for that thing here. I got it from an outfit in the

UK
=
called LJ Panels. I don=E2=80=99t often get carried away raving things,
b=
ut this one is the cats meow.
=20
Is it anything like the ones that Paul Hanson sold years ago?
Jim


They are similar, but they adopted the dual 'louver' type outlet the
Jonker=
s team came up with. No form on treatment on the interior. Te parts are
las=
er sintered nylon so finish is quite rough (something between sandstone
and=
wood) until primed/sanded, though some Polyprimer and sanding would

make
t=
hem really nice.

My guess is they work at least as well if not better due to having higher
s=
urface area with the double outlet even with the forward louver is partly
b=
locked by the attach point, though likely to make a bit more noise with
the=
air hitting the outlet without any organization taking place on the
inside=
..=20

Wish I would have made my test pod to quantify this stuff, but never did
th=
ough I do still make/sell the hatches I have been in fiberglass,
prefinishe=
d with PCL 907 white to a #320 grit

After installing a Nixon special in my 20, I heard a burbling sound coming
from
the vent.
I reduced the size of the extractor opening using mylar.
Each flight I would trim another 1/8 inch until the airflow, in the
cockpit,
returned to original levels. Very nice setup.....
I now hear air leaking around the flap while in negative settings.

What sounds are heard due to this design?

  #14  
Old October 20th 17, 03:21 PM posted to rec.aviation.soaring
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Default air extractor for asw19 and asw20

On Tuesday, October 17, 2017 at 1:12:58 PM UTC-4, Paul Agnew wrote:
The purpose of the extraction vent is to increase the available airflow to the cockpit. The ASW-19 has NACA vents under the wing roots to draw air in, but there is no clear path for it to exit. The extraction vent, and modification of the bulkhead to allow airflow, gives the air someplace to go and reportedly greatly increases the comfort level in the cockpit. Noise reduction is primarily due to being able to keep the canopy vent closed and a reduction of "pressurized" air leaking under the canopy seals.

Any performance benefits are a bonus in my book and not a serious consideration unless you are a hard-core performance tweaker looking for every .1% gain.

Paul A.


Some experience on this topic(about 80 sold for 9 types)leads me to comment..
1) Extractors can and do help ventilation(and removal of exhaled moisture). They are a big improvement in 19's and 20's, maybe a bit less so in ships with better ventilation to start with.
2)Sealing the cockpit area off from the aft fuselage has a meaningful effect on this extraction by increasing the pressure differential between the cockpit and ambient. Without sealing, the pressure reduction is limited by air coming from the rudder horn and hinge area that is low pressure, but not as low as the vent.
3) Canopies leak. It is better to have the leak be into the cockpit and not out over the wing root area. Commonly one of the noises heard is air being sucked in around the edges of the little vent window.
4) The extractor shown may well infringe on the patent applied for by JS or their resources.

FWIW- Hard core performance guy.
UH
  #15  
Old October 20th 17, 04:17 PM posted to rec.aviation.soaring
Jonathan St. Cloud
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Posts: 701
Default air extractor for asw19 and asw20

Not having seen the JS patent application, but cockpit air extractors have been in the public domain for a while now. Unless JS has something unique (perhaps the little airfoil in the middle), and unless they filed their patent before selling the first JS1 with an air extractor, JS is not likely to be granted a patent for the air extractor on the JS1c. The JS-3 extracts air out the underside of the fuselage. The JS-3 air extractor is new and I suspect that is what their patent is for.

On Friday, October 20, 2017 at 7:21:04 AM UTC-7, wrote:
On Tuesday, October 17, 2017 at 1:12:58 PM UTC-4, Paul Agnew wrote:
The purpose of the extraction vent is to increase the available airflow to the cockpit. The ASW-19 has NACA vents under the wing roots to draw air in, but there is no clear path for it to exit. The extraction vent, and modification of the bulkhead to allow airflow, gives the air someplace to go and reportedly greatly increases the comfort level in the cockpit. Noise reduction is primarily due to being able to keep the canopy vent closed and a reduction of "pressurized" air leaking under the canopy seals.

Any performance benefits are a bonus in my book and not a serious consideration unless you are a hard-core performance tweaker looking for every .1% gain.

Paul A.


Some experience on this topic(about 80 sold for 9 types)leads me to comment.

  #16  
Old October 20th 17, 04:34 PM posted to rec.aviation.soaring
Papa3[_2_]
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Posts: 606
Default air extractor for asw19 and asw20

IIRC (and I could be wrong) didn't the Mandl Extractor with DG predate Jonkers? At one point the Mandl was advertised as "patent pending" as well....

  #17  
Old October 20th 17, 06:33 PM posted to rec.aviation.soaring
[email protected]
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Posts: 1,575
Default air extractor for asw19 and asw20

On Friday, October 20, 2017 at 11:17:05 AM UTC-4, Jonathan St. Cloud wrote:
Not having seen the JS patent application, but cockpit air extractors have been in the public domain for a while now. Unless JS has something unique (perhaps the little airfoil in the middle), and unless they filed their patent before selling the first JS1 with an air extractor, JS is not likely to be granted a patent for the air extractor on the JS1c. The JS-3 extracts air out the underside of the fuselage. The JS-3 air extractor is new and I suspect that is what their patent is for.

JS mention of patent application as mentioned on their web site was for the incorporation of airfoil shaped additional element in the outlet area.

UH
  #18  
Old October 20th 17, 08:28 PM posted to rec.aviation.soaring
krasw
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Posts: 304
Default air extractor for asw19 and asw20

On Friday, 20 October 2017 17:21:04 UTC+3, wrote:
4) The extractor shown may well infringe on the patent applied for by JS or their resources.


Haha, you are taking about factory that "borrowed" ASH26 fuselage and added Ventus-2 wing geometry to create JS1.

  #19  
Old October 20th 17, 10:59 PM posted to rec.aviation.soaring
[email protected]
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Posts: 167
Default air extractor for asw19 and asw20

You mean the JS1 wing that differs in aerofoil, plan form, dihedral, winglet and structure from the Ventus 2 - that in fact shares no design features with it at all.
  #20  
Old October 21st 17, 03:17 AM posted to rec.aviation.soaring
Michael Opitz
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Posts: 122
Default air extractor for asw19 and asw20


4) The extractor shown may well infringe on the patent applied for

by JS or their resources.

FWIW- Hard core performance guy.
UH


I am buying one for my old ASW-19 which my brother now owns.
In emailing Alan, I mentioned the RAS patent infringement
musings.

Here is his response to that issue:

No patent infringement. My product was developed long before
Jonkers tried to patent their version and also uses different airfoil
sections, materials, technologies.

FWIW,

RO

 




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