Because the basics were worked out well in advance the radio gear has all fitted in with no unexpected problems. The throttle servo, bomb release servo and onboard / remote glow driver are located in the engine compartment, their leads have to pass through the firewall so the resultant hole needs to be sealed to prevent the ingress of fuel / oil into the main fuselage.
A standard grommet won’t work very well because the leads have their plugs permanently fitted, so I made a 2 part seal from a rubber wine bottle “cork”; another of those useful Christmas necessities!
An appropriately sized hole is drilled through the firewall, one half of the seal fitted in place, the leads / plugs threaded through, then the second half fitted, the rubber compresses around the leads forming a good seal.
The onboard / remote glow is located in the engine compartment in order to keep the glow plug power leads as short as possible, the control unit and battery are wrapped in foam and held in place by a cable tie. I’ve complicated the wiring somewhat by including a stereo, switched socket, which enables me to use a remote connection for starting and also, using a different jack plug, to charge the battery.
Previously I've used a homemade onboard glow driver, which simply switched on the glow at a preset throttle setting. But this one is an “intelligent” glow driver; it continuously monitors the glow temperature (actually the resistance of the element) and connects the battery only when required, whatever the throttle setting happens to be. In theory it should be a lot better, but I’ll let you know how it actually works in practice at a later date!
Linear Mode
