Above we have shown a couple of typical glow engine installations, with a Mintor 3M 140 and an
OS140RX. The photos of the Mintor 3M are taken in a Revolution Pro, not an Impact, but the
principles are very similar.
Pipe installation
Install and fix the tuned-pipe according to the pipe manufacturers instructions. This is usually at
2 positions; just behind where the pipe connects to the header, and also towards the back end
of the pipe - approximately where the inner cone begins. Make the pipe supports from scrap ply-
wood, glued firmly to the inside of fuselage with epoxy, and allow for some flexibility to prevent
the pipe fracturing.
Included in the kit is a CNC milled foam-board tuned-pipe floor and rear bulkhead, which can be
used to construct th separate compartment for the exhaust system of your chosen motor. The
balsa rails to support the pipe floor are already installed at the factory. Cut the pipe floor into 2
or 3 separate pieces to aid installation, and make at least the rear one removable with a few
small screws for access to the pipe mounts. The front part can usually be glued in position per-
manently. It is important to note that the pipe floor should completely seal off the rest of the fuse-
lage from air entering the cooling holes at the front of the cowl, and this prevents any overpres-
sure inside the fuselage which could pop off the canopy etc. You must seal the space between
the back of the cowl and the front of the landing gear support formers with thin balsa sheet, or
similar, to complete the pipe compartment.
Cut a large enough exit hole in the bottom of the fuselage for the warm air to exit from the pipe
compartment, and extend the outlet of your pipe with silicone tube to just outside the fuselage to
make sure no hot gases and oil residue can damage the fuselage. Please make sure that the
holes you cut have rounded corners so there is less chance of tearing the composite skin.
Note:
Using a side-exhaust motor in this plane is not recommended. Not only does it make the
engine installation much more complicated, but large cut-outs in the fuselage at the front could
affect the strength and definitely will not look pretty!
Fuel Tank, Receiver & Battery
Mounts
Basically the method of mounting these items
and their position is your choice, and will be
determined by the motor type used, and there-
fore where they need to be for correct Centre
of Gravity. We have not supplied any wood or
hardware parts for the installation of these
items.
The Fuel tank should be mounted on the
Centre of Gravity, and you can use the fibre-
glass wing spar tube to help with the support for this lightweight balsa structure. Remember
that you will need access to the wing securing plastic nuts, so either leave enough space at
the side of the tank support for access - or make the whole assembly easily removable, and
attach with Velcro strips or similar.
Do be extra careful that no fuel lines can rub on any carbon or fibreglass edges, as they will be
damaged in one single flight. Use rubber grommets, or soft plastic tubes, to protect them
where they pass through bulkheads and fuselage walls etc.
Composite-ARF IMPACT
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