Top Flite TOPA0155 - Manual (Page 21)

Mount the retracts
❏ ❏
R1. Cut two 3-5/8" [92mm] long retract rails
from the 3/8" x 1/2" x 24" [9.5 x 12.7 x 610mm]
maple stick (if installing the scale CJM retracts, cut
three rails and glue two of them together to make a
3/4" x 1/2" x 3-5/8" [19.1 x 12.7 x 92mm] aft rail).
❏ ❏
R2. Test fit the rails into the openings in the ribs
on the right side of the center section. If necessary,
bevel the openings to accommodate the rails. Test fit
one of the retracts between the rails to make certain
it fits. Make adjustments if necessary.
❏ ❏
R3. Securely glue the retract rails into position
with 30-minute epoxy. For additional strength, add
Great Planes Pro Milled Fiberglass (GPMR6165). Hint:
The outer ends of the rails are to be sanded at an angle
flush with the end of the center section. It may be easier
to do this before gluing the rails into position.
❏ ❏
R4. If installing Robart gear, file a flat spot on
the end of the wire strut near the top for the set
screw in the retract unit to lock onto. Mount the strut
into the retract units and tighten the set screw.
❏ ❏
R5. Position the retract unit between the rails.
Mark the locations for the holes for the mounting
screws. Drill appropriate size holes in the rails for the
screws. If using #6 screws, drill 7/64" [2.8mm] holes.
Use a rotary tool with a sanding drum to trim the aft
rail to accommodate the coil in the strut.
Perform steps 6 & 7 only if installing the Robart gear.
❏ ❏
R6. Cut the right landing gear strut to the correct
length. (For the long-strut option, the scale distance
from the wheel axle to the pivot point is 8" [203mm]. For
the “short-strut” option, the distance from the wheel axle
to the pivot point is 6" [152mm].)
❏ ❏
R7. File a flat spot on the end of the strut for
the set screw in the axle (not included, GPMQ4278).
The flat spots must be positioned so the axles will be
parallel with the main spars (as shown in the photo)
when the set screw in the axle is tightened.
Perform this step only if installing CJM scale
retracts.
❏ ❏
R8. Position the landing gear strut in the landing
gear cam (the cast aluminum part of the gear that
pivots to extend and retract the gear) so the axle is
parallel with the bottom main spar (though the photo in
the preceding step is of the Robart gear, the same idea
is illustrated). Tighten the set screw in the cam to lock
the strut in this position. Note: Before the gear doors
are mounted to the struts in step R10 on page 25, the
struts must be permanently glued into the cams with
JB Weld (epoxy specially formulated for bonding metal).
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