Hi Bill and Sue,
Some builders pointed out a potential corrosion problem with my choice of
aluminum. There are other choices. George Powell obtained a steel tube from
a builder in Germany, and whoever supplies the TP5/TP6 to Europa would
obviously also be able to supply a longer cut.
I like the idea of a Teflon coat on the TP4, but wouldn't have a clue on how
to apply it.
I am not really concerned about the corrosion issue. The torque tube is
prone to corrosion anyway, when moisture is present. I have seen the
corrosion on the exterior of other Europas, and if the exterior corrodes
then you can be sure that the tube's interior is corroded as well, unless
the necessary steps were taken before assembly .
I always apply a good coat of lithium grease, and the tailplanes should be
pulled off at least twice a year for a n inspection. I never had a problem
in that area.
Removal of TP5:
I tried it the hard way by making a micro oven inside an aluminum tube,
using a 20W halogen bulb and an oven thermometer with a remote probe for
accurate temperature control. The thermometer had an upper display limit of
200 degrees, and that was not hot enough to soften the redux I had used as
an adhesive. I have now seen another oven thermometer with a much higher
limit, but I have discarded that technique, unless I wanted to remove the
TP6.
Using the same tube, and with the inside opening sealed with a heatresistent
material (felt chair glides), I applied a good dose of heat with a
blowtorch. The tailplane is in an upright position, so that no heat finds
its way into the foam area. Using a narrow kitchen knife I probed the
adhesive on the outside of the TP5. When the redux had softened enough I
removed the heat and cut around the TP5 with the same knife, which had a
serrated edge and I was using it like a saw.
For the removal of the tube you need a locking pair of longnose pliers. Lock
it onto the edge and slowly remove the thing with a turning motion. You may
have to cut away a tiny bit of the plywood rib (2 x 5mm) to make room for
the pliers.
Now having said all that, I suggest you ignore the two techniques above.
Next time I would simply use the knife and heat it with a blowtorch before
cutting into the adhesive.
I didn't do any damage to the foam.
Installing the new TP5:
You need a small flashlight so you can see exactly what is inside the
tailplane.
Do a trial fit of the new tube and see if it butts right up against the TP6.
If there is any adhesive on the edge of the TP6, then don't disturb it, but
grind a piece out of the edge of the long tube.
I had to do that on both sides.
Once you have a satisfactory fit, mark the tube where it needs to be cut
off. I used a hacksaw and belt sander to do the necessary trimming.
Now take the tailplane and do a trial dry fit on the aircraft.
Remove the new TP5.
Use a narrow long spatula to apply floxed epoxy to the foam walls and over
the old adhesive. The flox should be fairly wet, and you need only coat the
first two thirds of the hole.
Put a liberal coat of neat epoxy on the tube exterior and insert it slowly
with a turning motion.
The tailplane is in the horizontalposition, and at the halfway mark remove
the surplus flox which has been pushed ahead of the tube. Remove more flox
again when the tube is fully inserted.
Now take some time to remove alltrace of adhesive inside the tubes. I used
rags dampened with acetone, on a long stick. I believe that vinegar can also
be used, if you are concerned about foam damage.
That is about it. Mount the tailplane on the torque tube to ensure perfect
alignment of the two tubes. If the alignment is not perfect, then adjust by
applying pressure at the tailplane tip in different directions until the TP4
slides in all the way. Make sure also that it was well greased.
After 4-5 hours of curing pull the tailplanes off again, just to make sure
that there is no bonding going on in case some more epoxy has seeped out of
the gap onto the TP4.
Then push it back on and leave overnight.
Hope that helps,
Karl
>From: Bill and Sue <bill.sue@orcon.net.nz>
>Reply-To: europa-list@matronics.com
>To: europa-list@matronics.com
>Subject: Re: Europa-List: Mod 73 alternative
>Date: Tue, 23 Oct 2007 14:55:56 +1300
>
>
>Yes I would be interested as I have not done mine yet .
>
>Mono XS
>ZK CHV
>914 Airmaster
>
>Rgds
>
>Sue & Bill
>
>
>Karl Heindl wrote:
>>
>>
>>
>>My original plan was to replace both TP5 and TP6 with a single tube.
>>After removing the TP5 I realized that there was no point at all in
>>removing the TP6. It is only necessary to ensure that it cannot move
>>inboard, which would then allow the TP12 to disconnect from the tailplane
>>etc. etc.
>>I simply replaced the TP5 with a longer alu tube from ACS, part number
>>03-37900. This butts right up against the TP6, and there is no way this
>>can ever move inboard. The tube is made of 6061 T6 aluminum.
>>Advantages:
>>A straightforward mod.
>>No cutting into the tailplane.
>>No misalignment problem with TP5 and TP6.
>>A permanent solution. ( assuming that there was a problem in the first
>>place.)
>>If anyone is interested I can give more details on how I did it.
>>
>>Cheers,
>>
>>Karl
>>
>>_________________________________________________________________
>>The next generation of Hotmail is here! http://www.newhotmail.co.uk
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>>
>>
>>
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>
>
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