Bill, John,

The air pressure inside the cowl w= ants to open the nose gear door.

You need a certain momentum to keep the doors cl= osed. It is defined by the Force of the push rod (it remains the same unless= we increase the diameter of the nose gear cylinder) x length of the arm

&nbs= p;

The leng= th of the arm can be changed by moving the attachment point of the push rod c= loser to the center of the airplane (this is what Brent Regan did if you rea= d my earlier post).

Unfortunately we can=E2=80=99t move the attachment point complet= ely to the inside because the nose gear won=E2=80=99t fit in anymore.

<= /o:p>

I hope I ge= t to check it out on the weekend. I will make new brackets then. It will be a= bent laser cut aluminum part that can be reproduced at almost no cost. If I= find a sound solution I let you know and I can make the brackets for you.

&n= bsp;

Ralf

&n= bsp;

From:= John Barrett [ma= ilto:2thman1@gmail.com]
Sent: Friday, June 21, 2013 10:15 AM<= br>To: lml@lancaironline.net=
Subject: Re: [LML] Re: Nose gear check 4P update

Hi Bill,

I do vaguely recall tha= t the brackets are either too small or in the wrong part of the door (per th= e manual) to get the proper mechanical advantage. I am thinking Brent R= egan came up with the discovery and the advice for fixing. It's been a= long time, but I think I either made new brackets or put them in a differen= t place or both. I could send photos and dimensions if you'd like. &nb= sp;My doors seem to function well although no one has flown formation with m= e to observe how they close in flight.

Let me kno= w,

John

Sent from my iPad

On Jun 19, 2013, at 9:03 PM, "= William A. Hogarty" <billhogarty= @gmail.com> wrote:

Hello Joh= n:

Yes, I think that we are talking about the sam= e item

=
Each nose gear door is actuated by linkage= (rods) that attach to the door using a small "L" shaped aluminum = bracket.

It seem that if the bracket were a littl= e larger, the pivot point (where the rod attaches) could be moved a= nd thus apply a little more pressure to hold the doors closed in fligh= t..

Any thoughts???? Bill H.
=

&nbs= p;

On Wed, Jun 19= , 2013 at 12:29 AM, John Barrett <2thman1@gmail.com> wrote:
Hi again Bill,

Is the bracket y= ou are referring to the horn that the push rod is attached to?

I'm not quite sure what the bracket is.
<= /div>

John

Sent from my iPad

On Jun 18, 2013, at 7:09 PM, "William A= . Hogarty" <bi= llhogarty@gmail.com> wrote:
= Hello John:

I bought two replacement aluminum doo= rs from Lancair; primarily because aluminum hinges are still in the pl= ane and they have always worked well. Dropping the doors was a simple m= atter of pulling the hinge pins.

I am interested i= n enlarging the brackets that activate the doors because both of the connect= ing rods ended up having a slight curve after about 180 hours so there is co= nsiderable pressure on those rods. In addition, the right door bracket= had a noticeable bend in it that I would like to resolve. If you have= any specs on your brackets, I sure would like to see them
&nb= sp;
On Tue, Jun 18, 2013 at 9:32 AM, Jo= hn Barrett <2thman= 1@gmail.com> wrote:
He= llo Bill.
=
i made my nose gear doors out of= graphite on my LIVP and used Carbinge to hinge them. Have about 70 ho= urs on the plane now with no glitches. Very happy with the results. &n= bsp;Can share design parameters if you are interested.
=

I also made graphite angle bar to hang them, but that might be o= verkill with your engine already being mounted.

Be= st,
John Barrett<= /p>
N31VP

Sent from my iPad

On Jun 18, 2= 013, at 8:46 AM, "William A. Hogarty" <billhogarty@gmail.com> wrote:
=
<= div>
Ralf:

I am making up a= new set of nose gear doors (don't ask)..

If you= fabricate a new door bracket, please let me know the how and what. An= d how they work. (maybe Brent has a pattern???

Ap= preciate the help.

Regards

Bill Hogarty

On Tue, Jun 18, 2013 a= t 4:45 AM, Chris Zavatson <chris_zavatson@yahoo.com> wrote:
<= div>
Ralf,
The Outback gear doors on the 320/360 suffered a similar fate. = ; The original actuation scheme couldn't handle the air loads. A small= pressure differential over a large area generates a lot of force.
Chris

Chri= s Zavatson
N91CZ<= /span>
360std
=
www.N91CZ= .net

From: "bronnenmeier@GROBSYSTEMS.COM<= /a>" <b= ronnenmeier@GROBSYSTEMS.COM>
To: lml@lancaironline.net
Sent: M= onday, June 17, 2013 11:08 AM
Subject: [LML] Nose gear check 4P up= date

Dear subscribers,

I did the nose gear check as des= cribed Jack Morgan and Charlie Kohler
earlier. Everything went very smoot= h and the plane did not move at all
even when the weight on the tail and c= hucks were removed.

I cycled the gear 5 times and every time the nose= gear door shut
perfect. This leads to the conclusion that my door shuts p= erfect after
take-off and reopens due to air-pressure like Brent Regan de= scribes
below.

On the in-flight picture you can see how the door g= ets pushed open. This
was at a pretty low speed - approx. 140...150= kts indicated - I assume
it will get worse if I go faster.

I atta= ched pics of my nose gear linkage versus Brent Regan's improved
nose gear= linkage - if yours looks more like mine you probably have the
same probl= em.

Since there was so much concern about my jacks I attached a pic o= f the
gear check. My jacks work reliable and the plane sits sound on them= .
They just don't have enough stroke. That's why I have little platforms<= br>that I slide in and out. The set up works reliable - it is just a little<= br>more work....

Ralf

-----Original Message-----
From:= Brent Regan [mailto:brent@regandesigns.com]
Sent: Wednesday, June 12, 2013 11:37 AM=
To: Lancair Mailing List
Subject: Re: Nose gear check 4P

Ralf w= rites:
"A friend took a picture of the belly of my airplane in flight wit= h the
gear up. It looked to me that the nose gear door was not completely=
closed."

The original factory nose gear door linkage geometry pro= vided too low a
mechanical advantage to keep the doors closed against the= internal
cowling air pressure during flight. On the door bracket, you ne= ed to
fabricate a new part with the link ball hole rotated about the hing= e
centerline towards the AC center. This will give a larger effective
= moment arm when the doors are closed. A slight kink in the linkage arms
i= s required. See pictures attached.

BTW, Selecting Gear Up while on th= e wheels is an incredibly bad idea.
Buy a decent pair of jacks NOW. Also= , do NOT strap the spinner to lift
the nose. Remove the top cowl and stra= p the propshaft.

Regards
Bren Regan
--
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=