I see, you use aluminum tube. The aluminum tube is probably 1/8 larger
(outside) and at .049 thick gives you about 3-4 thousandths clearance
for a better slip fit. Hence our concern with friction, thinking you
were using the stainless tube.
Bud
----- Original Message -----
From: Karl Heindl<mailto:kheindl@msn.com>
To: europa-list@matronics.com<mailto:europa-list@matronics.com>
Sent: Thursday, October 15, 2009 12:23 PM
Subject: RE: Europa-List: Mod 73
Pete and Bud,
I don't agree with the friction theory. My tailplanes slide on and off
with ease. If anything, it is easier now, as there is no lignup problem
with the two separate tubes. The torque tube is always lightly greased
for that reason, but also to keep corrosion of the torque tube at bay.e
I don't think that weight is an issue here. I use an alu tube and the
difference between that and the shorter steel tube is really minimal.
Actually, an increase in tail weight is beneficial for many Europas,
when you consider all the add-ons up front, like cs propeller,
instrumentation, autopilot, cabin heat, you name it, compared to the
original 80hp mono, on which the cg calculations were based.
Karl
-------------------------------------------------------------------------
-----
To: europa-list@matronics.com
Subject: Re: Europa-List: Mod 73
Date: Thu, 15 Oct 2009 09:19:16 -0400
From: pjeffers@talktalk.net
Karl,
When taking the tailplanes on and off the friction produced by having
6 or 7 times the contact are between the torque tubes and the TP bushes
would be enormous and add a significant weight penalty to an area with
great lever arm IE CG considerations.
Re the plaster stuck onto stainless. This is the significant
improvement made by the mod in that disbondment is now prohibited, by
introduction of a physical barrier to migration of the bush. Previously
it was only held in place by the adhesion of stainless to structure in
one linear direction.
Pete
-----Original Message-----
From: Karl Heindl <kheindl@msn.com>
To: europa-list@matronics.com
Sent: Thu, 15 Oct 2009 12:19
Subject: RE: Europa-List: Mod 73
Surely, the objective of mod 73 was to prevent the tailplanes from
moving outboard. There is no guarantee that this 'plaster' stuck onto
stainless is going to last the life of the aircraft.
What is wrong with my simple fix of replacing the TP5 with a long TP5
reaching up to the TP6, ensuring that the TP6 cannot ever move inboard.
This also fixes another problem, namely the disbonding of the TP5s ,
which has happened to me on both tailplanes.
BTW, I have never noticed any tendency of the tailplanes migrating
outboard. Whenever I remove the tailplanes at the end of my season, the
pip pins are still as free and easy as when they went in.
Karl
> Date: Thu, 15 Oct 2009 10:43:46 +0100
> From: grahamsingleton@btinternet.com<>
> To: europa-list@matronics.com<>
> Subject: Re: Europa-List: Mod 73
>
<grahamsingleton@btinternet.com<>>
>
> Fred Klein wrote:
<fklein@orcasonline.com<>>
> >
> Fred
> imho John's solution is adding more engineering to fix a symptom. I
> would prefer removing the cause, which is relying on the adhesion of
> epoxy to stainless steel. Purely mechanical, no true bond. Better to
> make a glass tube properly laid up onto the foam core and the ribs,
> lined with a full length tube with lightening holes. Much more
expensive
> in labour but hey, we can always pay ourselves a bit less that day
;-)
> The problem is the stainless inserts are not always circular and a
bit
> of swarf from the drillings make them jamb. Trouble!
>=====================
>=================
>
>
>
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