Composite-ARF SPARK Instruction Manual page 29

Composite-ARF SPARK
Increased Cooling
If the speed controller still becomes too warm during normal flying, or you will operate in very
warm ambient temperatures, we recommend that you use the following method to increase the
cooling flow thru' the heat sink fins on the speed-controller (see diagram below).
Increase the depth of the 3 mounting blocks by another 5 - 6mm, so that you can fit the speed-
controller inverted, with the cooling fins on the bottom, making sure that they are only clear of
the duct top surface by 1 - 1.5mm in the centre. Cut a rectangular hole (with radiused corners)
in the top of the inlet joiner under the back 30 - 40% of the area of the controller. Start by mak-
ing the size of the hole approx. 35mm wide and 25mm deep, and enlarge if needed. In conjunc-
tion with the inlet slots in the canopy frame, and the baffle above the speed-controller, this will
promote a very strong airflow through the cooling fins.
NB: If using this method, then you do not need the 2 small holes in the duct 25mm behind the
controller, as mentioned above, and if already cut they can be covered or taped over.
Increased Cooling Airflow
Cooling air from
nosegear opening
Cooling Baffle and Slots
Although some air enters the fuselage thru' the nose gear opening, and travels around the bat-
tery packs to cool them and then towards the rear of the fuselage, it is normally necessary to
have more inlet area than this.
We advise you to cut a pair of small slots on both sides of the canopy frame as shown, about
15mm behind the clear canopy, to increase the
cooling inlet air volume. As the canopy frame is
very lightweight you will need to reinforce these
areas first, by laminating one layer of 160 gram
fibreglass cloth just onto the area of the slots
(about 60 x 60mm).
Sand and clean the areas carefully and laminate
the cloth with slow (24 hr) epoxy resin; only just
enough epoxy to wet out the cloth is needed.
When the resin is fully cured, mill and file the 4
slots, each approx. 6mm wide and 40mm long,
baffle to force all air
to pass thru' heatsink
Cooling air from
canopy slots
29
techsupport@composite-arf.com
speed-controller
mounted inverted, with
heatsink underneath
hole in duct approx.
35mm wide and
25mm deep.