Thanks Rick, That is a good idea, hinging from the bottom. The work in 3506 is so ugly I wonder if it was a modification done by the Thais who would likely have always kept the duct open ? I have tried to get in touch with Herr Hoffmann to ask about other design details but the two email addresses I have for him have bounced. Retired ? Cheers
On Wed, Oct 6, 2021, 23:00 Ric Sutton <ricinthel...@outlook.com> wrote: > i found that there was a piece of metal riveted into the duct to stop > water blowing straight through(at least this is what i think its for) i > found that in the closed position it was against the firewall and in the > open position it was against this strip of metal so it didnt flow air > either way. what i did was change where it was hinged from( changed from > top to the bottom of the duct). works much better. not sure if the bend in > your case is to fit around some body work or as you say direct air > against it to stop it fluttering. mine does not seem to flutter yet > cheers > ric > ------------------------------ > *From:* dog@lists.riverland.net.au <dog@lists.riverland.net.au> on behalf > of Ian Mc Phee <mrsoar...@gmail.com> > *Sent:* Wednesday, October 6, 2021 6:02 AM > *To:* DOG LIST <dog@lists.riverland.net.au> > *Subject:* Re: [DOG mailing list] Cabin Air NACA duct > > Sorry I am away from dimona so no photos but I fitted either side of > cockpit two NACA inlets with a ball vent which opens and closes. I copied > what the HK36 has. > > I found the one on top of cowl was limited for air for ventilation and > that flap is not reliable. I guess it can supply air to canopy but from > memory the hk36 has no air going onto canopy. > > This on top h36 is a poorly shapped NACA in my opinion. I believe 1. the > shape of NACA is critical with little nick near wide part. 2. A sharp edge > on the NACA upper serface 3. A wing section on the right angle end of NACA > on inside and this sucks air in to cabin. 4 is the angle of ramp but its > is less critical I believe. 5 the alignment we ith airflow is moderately > important (I put thick black string where they were going and had it > photographed on landing so I had the air flow line) > > A friend did his thesis year on NACA air intakes and explained it one wet > no flying day. > > Ian Mcphee > +61 428847642 > > On Wed, 6 Oct 2021, 11:15 Tom Preisser <t...@ecoflight.com> wrote: > > I am not clear what you mean, Ian. > Tell me more please. > > On Tue, Oct 5, 2021, 19:51 Ian Mc Phee <mrsoar...@gmail.com> wrote: > > I gave up on it and fitted 2 side NACA ducts as per HK36. > > I think that flap is opposite to what you think. > > Ian McPhee > +61 428847642 > > On Wed, 6 Oct. 2021, 05:46 Tom Preisser, <t...@ecoflight.com> wrote: > > Gentlemen, > For many years now I have wondered why someone ( Factory ? Thais ? ) bent > the bottom of the flap that shuts off air through the fresh air louvres and > canopy demister vents. I have assumed that it fluttered in the open > position, and the bend was to prevent this from happening. However, with > this bend it will no longer completely seal the incoming air ( or rain ) > entirely, nor will it allow an unobstructed flow of fresh air through the > duct when open ( due to interference with the screen ). Were I to > straighten the bend to obtain a flat flap, I would not be able to open the > flap fully. > What do yours look like? > Cheers, > Tom. > > --------------------------------------------------------------------- > You are subscribed to the Dimona Owners Group mailing list. > This list is archived in public. http://waikeriegliding.com/dog/ > To unsubscribe, send email to: dog-unsubscr...@lists.riverland.net.au > >
