Hi Roger,
It's been a while since we last chatted. I hope E04 is doing well with
new orders these days. Thanks very much for chiming in with further
detail and advice.
As my frame is not yet installed in my build I have a couple of
questions:
1- Is E04 considering redesigning the frame design to eliminate the need
for the offset weld brackets? (thus including a matching intermediate
frame)?
2- How are new frames from the factory designed? With longer offset tabs
which have longer welds (welded further back along the upper tubes) to
reduce the bending forces, and with thicker walled upper tubes?
3- Are the new frame's welds properly annealed to reduce brittleness?
4- **Were the old frames annealed (as far as you are aware)?
5- How much would a new (redesigned) frame be?
6- since my frame is not yet installed, Could I request a pair of
mod-inserts which are the entire length of the upper tubes (to provide a
more secure mounting with the tunnel/frame mounting bolts)? And how much
would these longer inserts cost?
As I've already ordered some stage-1 related parts from E04 (parts
shorted to me by the previous 'owner' of Europa), you already have my
Credit Card information. My shipping address is:
Peter Zutrauen
4 Kinalea Crescent
Stittsville, ON
Canada
K2S 1L1
Once I receive answers to my questions above, I'll place an order
accordingly. Thanks again!
Cheers & blue skies,
Peter Zutrauen
Europa Builder A239 dual-wing
http://europa.zutrasoft.com
Ph: 613-831-0348
Cell: 613-850-5551
PS- on a side note, it was my understanding that the previous company
had a new cowling design in the works. Are you going forward with their
newer & assumed cleaner design? Would you have any pictures of it?
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Roger Bull
Sent: Friday, January 19, 2007 3:42 PM
Subject: RE: Europa-List: Mod 72 question
O.K. Bob, you woke me up!
Rob Housman's answer is on the ball. Using Redux would necessitate
increasing the clearance between the original tube and the new inserts.
The
Redux would not be strong enough to withstand the bending load, which is
the
critical part of the overall stress. The insert is intended to be a
close
but not interference fit in the outer tubes after reaming. Any small
clearance which may exist after fitting the new tubes will be taken up
by
deflection caused by the initial load applied by the weight of the
engine
and propeller.
The bending load is applied both by the vertical load from the weight of
the
engine acting some 2.5" approx forward of the weld affected area, and
also
by the small tube which is about 1" above the main horizontal tube. The
forward thrust from the propeller creates this bending load. To that
has to
be added on one side the torque reaction. (Distances are from memory as
I am
writing this fom home).
I have made a small change to the Mod leaflet to make the applicability
criteria a little clearer. The factors which affect applicability are
engine and propeller weights and c's of g forward of the undercarriage
mounting frame, and the engine torque.
Briefly all Rotax engined Europas, except those with classic engine
installations and light propellers as defined in the Mod leaflet, will
need
to incorporate the Mod. So all Rotax engined XS models, regardless of
whether 912, 912S or 914, and regardless of propeller will need the Mod.
Europas with engines other than Rotax will need to be checked on a case
by
case basis. We have already established that Europas with the Jabiru
3300
engine will need the Mod.
It was orginally intended that the news of the Mod would be promulgated
by
the PFA and EA4 on their respective websites simultaneously -
unfortunately
that did not happen. The PFA have now updated their Type Acceptance
Data
Sheet to include Mod 72.
We realise that quite a long time has elapsed since the failure took
place
that gave rise to this Mod. It was necessary first to establish that the
failure was not a one-off due to a unique set of circumstances; research
into the original calculations established that there was a more general
problem. The we had to devise a satisfactory solution that would be
reasonably straightforward to incorporate, then carry out tests to prove
the
fix. Then the method had to be agreed with the PFA, and the Mod leaflet
written. This latter exercise proved rather drawn out, and several
drafts
were needed before the current version was agreed. Establishing why the
original error in stressing was made during the reign of EMIL proved
almost
impossible, as the engineer concerned died a few years ago.
I realise that many people may feel that an unnecessary fuss is being
made
about this Mod, but a look at the attached photo of the first, but not
only,
failure should prove interesting.
Best regards,
Roger Bull
EA4
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com]On Behalf Of Robert
Borger
Sent: 19 January 2007 1:48 pm
Subject: Europa-List: Mod 72 question
Fellow Europaphiles,
The Mod 72 topic has become too quiet. I've decided to give it a poke
and
see if I can wake it up again.
I have all the various bits for Mod 72 on order. Etching primer,
ACF-50,
16.5 mm hand reamer & Mod 72 kit.
I am wondering why the heavy wall tubing is not bonded in place with
something like Redux.
Is the press fit good enough to support the frame?
Would it be better to Redux the insert in place? Better support and
corrosion protection?
If not, why not?
Good building and great flying,
Bob Borger
Standing by, wearing my nomex undies, ready for the flames.
P.S.
The reamer will be available for loan to any Europa builder in the U.S.
or
Canada who needs it for Mod 72.
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