Gear Doors - Carf-Models CL-41 Tutor Manual

Gear Doors

The main gear doors are factory hinged ready
for the operating system to be installed.
CARF recommend using Robart 165 rams as
supplied in the Air kit part No 250550. These
are connected to the horn using ball links the
ram requires a 2-56 stud which screws into the
ram rod. Remove the base mount supplied with
the ram and use an M4 x 30 Allen screw as the
mount. Fix the base end with an M4 T nut and
ply mounting disc provided. Mark a line 30mm
down from the wings lower surface, this is the
centre line of the ram base mount. The standard
length Robart 165 ram is exactly the correct
stroke, so actually positioning is critical.
The operating horns supplied with the Tutor will
require some trimming to function perfectly.
Looking at the photo for reference remove
approx 3mm (1/8") from the mounting face and
notch the horn around the hinge tube keeping
the operating point as close to the hinge tube
as possible. (Photo 6) (This helps reduce
the required stroke) Make up the ram with a
suitable ball link-we used Graupner part No
4618.55. Fix the ball to the outside of the horn
using an M2 x 10 screw and M2 nut. Fully
retract the ram and attach the ball link. Holding
the gear door approx 10 degrees off vertical,
tack glue the ply disc with a few drops of CA.
The ram needs to be fully closed with the door
open enough to clear the wheels as they swing.
It is important that the ram has not fully opened
with the gear door completely closed, this puts
a pressure on the door keeping it shut. Small
adjustments can be made to the base mount
position to ensure the doors close fully. Once
satisfied, fully bond the plywood mount to the
wing spar.
Note: Where the ram/horn passes through the
root rib ensure the corresponding opening in the
fuselage matches the wing root one. (Photo 7)
Composite ARF Tutor T-114 manual – techsupport@composite-arf.com
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