Just finished filing out the slots in the side of the fuselage moulding
for the trim link rod to connect to the trim tab drive pins. I was
gradually driving the servo from one end of its travel to the other
while filing to ensure the slot is OK for all combinations of stick
position and trim setting. I am worried to discover that the fork of the
servo actuating rod connected to the end of the trim bellcrank TS03 is
contacting the trim link rod TS05 when full up trim and full up elevator
are applied simultaneously.
I observed these metics.
Holding the tailplane at full up (about 14 degrees up from the neutral
position in-line with the fuselage fairings) and driving the trim servo
---From neutral towards full up, results in the plastic fork making contact
with the trim link rod as soon as the "full up trim" LED lights. If I
let it run on, the trim motor slows slightly, sounding a bit distressed
(guess how I found this problem!) and the bellcrank mounting trunnions
and top of the aft bulkhead start to distort slightly.
Driving the servo to full up trim with the tailplanes full down allows
the trim to reach its end stop without distress. Now if the tailplanes
are raised towards full up, the servo rod fork makes contact with the
link rod at about 11 degrees up from neutral. Trying to move it beyond
that causes visible movement of the aft bulkhead where the servo is
mounted.
I am attaching a couple of pictures to show the situation with full up
trim set - first one (p1040971_small.jpg) shows how it looks with the
tailplane TE nearly full up and the second (p1040973_small.jpg) shows it
with the tailplane TE full down (rest position, as no mass balance
installed yet).
I did check carefully that the servo travel was correct with respect to
the damper slot in the bellcrank mounting trunnions, and I used the
template for positioning the trunnions according to the manual.
Can anyone advise me what to do about this? I don't think I've ever
heard it mentioned before.
in friendship
Rowland
Europa 435 G-RODO
| Rowland Carson ... that's Rowland with a 'w' ...
| <rowlandcarson@gmail.com> http://www.rowlandcarson.org.uk
| Skype, Twitter: rowland_carson Facebook: Rowland Carson
| pictures: http://picasaweb.google.com/rowlandcarson
|