I finaly decided to repair my play in the TP 12 by glueing it to the TP 4
torque tube.
I used Loctite 603 (for lightly oil contaminated parts, shear strength
3.700 psi) which I applied on the torque tube on the 10 mm inbord of TP 12.
I did this only after careful in-situ testing how to soften the glue again
in case of disassembling without heating the aircraft structure or
softening the Redux holding the TP 11 bushes.
In case you are going this route, here is the way to go: take a halogen
bulb of 150W (size: 75 mm long) which will be centrally mounted between two
discs (made of some scrap of the firewall material) with a diameter of
34mm. The discs are hold together by two threaded wire rods (2mm diameter)
each with a nut on both ends. For the electrical contacts I disassembled
the halogene spot (cost Euro 5,--) and used the small metall contacts which
I mounted centrally to the discs. The electric cables which are crimped on
the contacts are running on each side of the assembly. The complete
assembly is than slided into the torque tube and placed exactly under the
TP 12 well inboard of the TP 11 bushes, where the glue is. One cable will
go to the left and one to the right end of the tube. When you switch on the
light, very concentrated heat will be emitted by the bulb which heats the
tube from the inside on a length of not more than 70 mm. The Loctite needs
about 150=B0C to soften completely. This temperature will be reached easily
after 2 to 2,5 minutes. You can than slide the TP 12 out again and swich
off the heat. The "firewall discs" help to concentrate the heat and the TP
11 bushes don't get any more than "handwarm" (not more than 40=B0C).
Thanks to Jim N. for this idea! It works perfectly.
For those who are still building, make shure you are using anchor nuts to
fix the servo motor and the trim assembly below as well as shackles or
turnbuckles for the safety cables which are holding the
counterwight......this will asure you an easy disassembly of all the
"mechanics" in the back of the fuselage; something which inevitably will
happen sooner or later..... Obviousely you'll need also an access panel at
this very strategic place.....You may also file the heads of the pins
square to be able to turn them with a spanner to position the hole of the
split pin.
Have fun...it's just a 10 minutes fix (I'm Ivan's disciple....)
Klaus
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