Carf-Models Ultra Lightning Instruction Manual page 4

Why? Because the axis of the hinge is not at the centreline
of the aileron/elevator, so it moves slightly in and out when
Centreline of hinge axis
operated, and the control surface gets a little "smaller" in
surface area when moving downwards.
The slot needs some explanation, too. The cut line is
exactly in the correct position so that the control surface
Phenolic control horn
slides under the wing skin smoothly. If the cut was a few
mm forward or backwards, it would not work properly. So,
make sure that the lip is not damaged, and that the control surface slides under this lip perfect-
ly. It will not lock at any time, as long as the lip is not damaged. If damage occurs, you can cut
a maximum of 2-3 mm off the lip on the wing in front of the control surface, but you should never
cut off more than this.
Servo Choice:
We strongly recommend that you use the high-torque digital JR/Graupner 8511/8611 (or 8811)
servos on all the main flight controls, and the milled plywood mounts are specially designed for
these. An alternative is the Futaba S9351. Please see the recommended servo list on page 6.
Servo Screws:
Fix the all the servos into the milled plywood servo mounts using the 2.9 Ø x13mm or 16mm
sheet metal screws provided in the kit, not the standard screws normally supplied with servos
by the servo manufacturer. This is because all the holes in our milled servo mounts are 2mm
diameter, due to our CNC manufacturing process, and this is too big for the normal screws.
Take Care:
Composite sandwich parts are extremely strong, but fragile at the same time. Always keep in
mind that these contest airplanes are designed for minimum weight and maximum strength in
flight. Please take care of it, especially during transport, to make sure that none of the critical
parts and linkages are damaged. Always handle your airplane with great care, especially on the
ground and during transport, so you will have many hours of pleasure with it.
To protect the finished paint on the outside of the model from scratches and dents during build-
ing, cover your work table with a piece of soft carpet, cloth or bubble-plastic. The best way to
stop small spots of glue getting stuck to the outside painted surfaces is to give the whole model
2 good coats of clear car wax first, but of course you must be sure to remove this 100% proper-
ly before adding any additional paint, markings or trim. Alternatively you can cover the majority
of the fuselage with the bubble-plastic used to pack your model for shipping, fixed with paper
masking tape, which also protects it very well.
Adhesives
Not all types of glues are suited to working with composite parts. Here is a selection of what we
normally use, and what we can truly recommend. Please don't use inferior quality glues - you will
end up with an inferior quality plane, that is not so strong or safe.
Jet models require good gluing techniques, due to the higher flying speeds, and hence higher
loads on many of the joints. We highly recommend that you use a slow filled thixotropic epoxy
for gluing highly stressed joints, like the hinges and control horns, into position (eg: Hysol 9462).
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