<<Perfect answer Nev..>>
Not quite.
<<..Back then, we didn't take into account that builders would take it
apart
/ reassemble / take apart / reassemble it the wrong way round / take
apart /
reassemble and wear the holes .......... >>
I don't believe the parts manufacturing execution was up to the mark.
In my own case the pins were taken out from the pre-assembled torque
tube
assembly and put back in once. Only. And in the correct holes. Looseness
appeared as soon as the jointing compound that I used between the tubes
let
go, then got worse.
Further, I don't believe the originals were a reamed fit; merely drilled
(albeit with a decently sharp drill) but the edge of the holes had then
been
enthusiastically deburred, thereby removing locally a significant amount
of
tube wall thickness where the pins bear.
I replaced 400 hours ago with oversize pins driven in with a hammer.
There
has been no subsequent degradation of fit.
So, the design was OK, but not the execution of the parts; be that at
the
Factory or maybe in some cases compounded by the builder.
Duncan McF.
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Trevor Pond
Sent: 13 October 2012 09:13
Subject: Re: Europa-List: Re: Mod 73
Perfect answer Nev.
Best regards
Trev
Sent from my iPhone
On 12 Oct 2012, at 21:48, Neville Eyre <neveyre@aol.com> wrote:
Hi Alan,
It's a pity you were not available when we were working on the design
and
manufacturing process all those years ago, we could have done with an
expert
to help. Sorting out all of the thousands of items with your help would
have
been welcome.
Everything could have been made bullet proof, trouble is the Europa
would
have weighed perhaps 1200 + pounds, with little payload ?
A number of options are available to you.
1]. Submit your new [improved] design to L.A.A. you might get it through
in
a year or two ?
2]. Call Karen at Europa, have your Credit Card ready, and order one of
the
new [ improved] torque tube assemblies. With hindsight, and less
pressure 18
years on, Europa have done a re design on this. Back then, we didn't
take
into account that builders would take it apart / reasemble / take apart
/
reasemble it the wrong way round / take apart / reassemble and wear the
holes .......... or they would smack the mass balance weights onto the
stop..... If you take this option, you might have to ream out the bores
of
the TP5 /TP6 sleeves in your tailplanes to allow the torque tube to
slide
on easily, as they were matched to each individual torque tube. Easy but
time consuming, with a broom handle and emery cloth.
Almost certainly you will need to sweat out the TP13 bushes [ the four
1/4''
bore drive bushes in the inboard rib] and re pot them to match the drive
pins, simple job with a heat gun and 1/4'' bolt, and some epoxy. This
heavy
duty item is, funnily enough, heavier.
3]. Remove the entire torque tube assembly, mark everything as to their
orientation [ horn , drive plates and nylon spacers relative to the
torque
tube] and establish the scale of the wear [in the holes, not the pins].
If
the pins are the original 1/4'', and the holes are not too worn [ they
might
be now if you have been swinging on the tail to check wear] the next
size up
was 5/16''. Not sure if these are available from Europa, as they go
directly
to 10mm now, bigger is better, but doesn't give you another shot at it
if
you mess up on reassembly. The new holes in the tube / fiting need to
be an
interference fit, as in if you can push the pin in by hand, the jobs
buggered before you fit them. I have just done this job last week to a
monowheel with 800+ hours on it. very slight play but as it was in my
workshop it made sense to sort it for another 800 hours life.
Get a machine shop to ream the holes out to 0.007'' smaller than the
pins
ACTUALLY MEASURE, and make sure you don't lose the relative positions
of
the fittings when this is being done. If there is significant play
between
the drive plates, ensure they are clocked to be in allignment with each
other during the drilling process. DON'T trial fit the pins ! It is a
once
ony job ! On reinstallation, to drive the pins in you will need a 4lb
copper
hammer.With the nip of the tube on the pin, it will need a firm wallop
to
drive the pins in, should be a '' doink, doink, doink, donk '' Mark with
a
felt pen on the head of the pins the axis of the split pin hole so you
can
have them vertical when you insert them, it helps to taper the lead end
of
the pin back to the split pin hole to assist insertion, and lube the pin
with thin oil.
Depending on whether the original builder put the inspection / view
panels
in the place described in the Build Manual, or chose to delete / move
them,
this is either a 3 hour each way job + the machining work, or a couple
of
days marathon swearing session.
This work will need inspecting, and entering in the aircrafts Log Book.
Regards,
Nev.
-----Original Message-----
From: Alan Carter <alancarteresq@onetel.net>
Sent: Wed, 10 Oct 2012 23:54
Subject: Europa-List: Re: Mod 73
<alancarteresq@onetel.net>
Hi Brian.
To me it feels like play, i will check again, and slide the Stablators
off
and
check inserts making sure they are bonded.
I am just a pilot but i could have done a better job in designing this
linkage.
As this has the possibility of grounding the aircraft for some
considerable
time, due to the fact that clamps are individually made to size, Why
has,t
something not been done about it.??
Why can,t you get a complete unit with clamps already made, so the job
could
be
done in one go, say a day, not grounded for 2 months.
Alan
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