If the position is OK, or close enough, then remove the
cowling and drill the other top mounting hole, and fit the 2
nd
blind nut and bolt in place. If you need to increase the
moulded in sidethrust a little, use a slightly thinner pack of
washers on the 2
nd
bolt. Again fit the cowling and spinner
backplate to check alignment.
If correct, then drill the last 2 holes and bolt the motor in
place, adjusting the thickness of the washer packing to
leave a minimum 3mm (1/8”) gap between the back face of
the spinner backplate and the cowling. The centres of the 4
mounting holes of the DA-150 are 80mm horizontally, and
90mm vertically, and with the first 2 holes drilled it is easy
to mark the other 2, using a 90° square and offsetting from
the 1st two holes.
NB: In the instance that your 1st hole was not in the correct
place you can enlarge it a little with a file to correct it, and
refit the blind nut, or plug the hole with a piece of hardwood
dowel, glued in with slow epoxy and re-drill in the correct
position when it is completely cured.
Finally glue the 4 blind nuts to the inside of the firewall and
fix in place with a little 30 minute epoxy.
Adjustments to sidethrust after the first flights, if needed,
can be made by adding or removing washers between the
back of the engine mount and the firewall. In the future we
hope to add the mounting hole dimensions for other popu-
lar motors to these instructions, or on the website.
Throttle servo:
Make up the throttle servo mount, as
shown, from the milled plywood parts supplied, and glue
the mount onto the baseplate with 30 minute epoxy and
milled-fibre mix. Remember that this is mounted to the back
of the firewall, and therefore will suffer from some vibration
- so please prepare the surfaces for gluing properly by
sanding first. The M3 threaded rod and clevises for con-
necting are supplied in the hardware pack.
All DA motors need quite a lot of servo throw to get the full
throttle range, so make sure you can fit a long output arm
on the servo, and allow for this when cutting the clearance
hole in the firewall for the linkage.
Standard Mufflers:
If you are using a standard muffler just
mount it onto the engine and check if you need to cut clear-
ance holes in the bottom of the cowl for the exhaust outlets.
Mini-Pipes:
An internal mini pipe installation is a little more
complicated than the use of a standard muffler, but some-
times you don’t have any choice, especially if you have
noise problems at your club field. In Europe noise is always
Composite-ARF SuperXtra 330L
(3.1m span)
26
(above) We highly recommend the
MTW mini-pipes, headers and
teflon connectors, which C-ARF
can supply as an option. Also seen
here is the steel strip, bent to the
shape of the 2 mufflers.
The Throttle servo mount is assem-
bled from the milled plywood
parts, and fixed to the back of the
firewall with three M3 bolts and
blind-nuts, as below.