site side of the fuselage to the cylinder - and use a ‘cross-
over’ header to give you enough length.
Included in the kit is one cnc milled plywood mount to suit
the TD110K, or similar 80mm diameter canister. Insert
20mm lengths of the hard silicone tube in the corner slots
to make the isolation mounts, in the same way as shown for
tuned pipe mounts. The plywood mount can be screwed to
the front of the landing gear mount bulkhead with 2 of the
Ø3.5 x 18mm sheetmetal screws included in the hardware
pack.
Enlarge one of the semi-circular cutouts in the plywood
bulkhead at the front of the landing gear mount as required.
Make sure that there is at least 6mm (1/4”) clearance
between the bottom of the canister and the top of the car-
bon landing gear - as the heat could damaged it with
extended exposure to the high temperatures. You can pro-
tect the top of the carbon, if needed, by adding a thin ‘sac-
rificial’ plywood plate, glued to the top of the carbon with
clear silicone adhesive.
Desert Aircraft DA-100
The DA-100 installation and set-up uses the same princi-
ples and motor centreline positions as detailed above.
Because it is a twin-cylinder motor it has lower vibration lev-
els and it is not necessary to incorporate an anti-vibration
mount. The motor fits fully enclosed in the cowling.
The photos below show the DA-100 installation in one of our 2.6m 330L’s (Futaba scheme) but,
of course, as the motor-dome/firewall on the 300SX is 30mm further back you will need to use
30mm long engine standoffs to ensure a 5 - 6mm gap between the rear face of the spinner- back-
plate and the front of the cowling - instead of the short stack of washers shown here. Other than
this the installation is identical.
Mark the horizontal and vertical motor centreline positions accurately on the front of the firewall
in same manner as described at the beginning of this section, dependant on your spinner diam-
eter. The 4 mounting holes for the DA-100 are 70mm apart
horizontally, and 80mm apart vertically. Mark half of these
dimensions equidistant either side of the centrelines and
bolt the motor to the your standoffs. Drill the 4 mounting
holes through the firewall, 6mm diameter, and secure the
standoffs using the M6 x 20mm allen bolts and washers
supplied in the hardware pack, with a little Loctite for secu-
rity. If you need to adjust the thrustline very slightly after
trimming flights, then add thin 6mm I.D washers between
the front of the firewall and the back of the standoffs. (see
photos P17 and P18)
Fit your headers/manifolds to the motor and cut the neces-
sary holes in the lower part of the motor dome to suit.
Composite-ARF Extra 300SX
(2.6m span)
27
(above) A single 80mm Ø can
(TD110K shown) can be fitted - but
you may need to use a cross-over
header to get the correct length.
(below) DA-100 mounted on a
330L. The mounting system is iden-
tical for the 300SX, except that you
will need 30mm long stand-offs,
and accurate thrustline alignment is
even easier!
(above) MTW headers & canisters
are available as optional items form
C-ARF. Shown here are the TD75K
cans and headers for the DA-100.
