Wing Post Socket Attachment to Rolled Motor Sticks

From: calgoddard <calgoddard_at_yahoo.com>
Date: Fri, 13 Jul 2007 19:27:50 -0000

After building many planes with solid motor sticks, I am
experimenting with my first rolled motor sticks for planes of 3
grams and more (I'm not ready to take on F1D yet!).

My question relates to how to best attach the wing post sockets to
rolled motor sticks.

Traditionally I mount the wing post sockets on a very thin strip of
balsa (that I call a saddle) which can be temporarily affixed to the
side of the solid motor stick. This allows them to be moved fore
and aft during trim flights for optimizing the CG. Once the best
location for the main wing is determined, the sockets are
then "permanently" attached to the side of the solid motor stick at
the desired locations and any remnanent wing post saddle is removed
to save weight.

I understand that with a rolled motor stick the wing posts extend
throuh holes in the motor stick itself. Obviously you don't want to
be drilling multiple sets of holes in the motor stick and you can't
really remove wing post sockets from a rolled motor stick without
risking damage to the motor stick. Affixing the wing post sockets to
the side of the rolled motor stick seems problematic but maybe this
can easily be done without problems.

I can predict where I think the CG will be, but trim flights are
really required in my experience to get the CG in a location where
the plane is stable in flight, climbs, cruises and decsends as
desired, recovers nicely if it hits the ceiling, and will achieve
max duration. I'd rather not optimize the CG by using ballast.

I know that many will say that for planes of this weight (3.0 grams
and above), don't bother with rolled motor sticks just pick out good
wood for a solid motor stick. But rolled motors sticks allow you to
save weight and use a stronger (heavier) main wing spar, stronger
wing posts, etc. while largly elimnating motor stick bending and
twisting problems.

Any thoughts? Any referals to articles, posts or pictures? Thank
you.
Received on Fri Jul 13 2007 - 12:28:47 CEST