Radio kit & batteries
My decision to include functional lighting and a rotating searchlight in addition to the usual throttle and rudder functions meant that I had to revise my initial choice of radio kit from a two channel system to at least a four channel system.
My final choice was actually a Turnigy TGY-i6 six channel system from Hobbyking. The reviews I read during my research were very complimentary and it certainly fitted within my budget, I actually view it as extraordinary value for money at £44 for the TX/RX combination, my last R/C system was a MacGregor single channel 'clunk-click' system for £20 back in 1970-something when that sum was my weeks wage! 😯
The programming options are predominantly for aircraft and helicopter modellers but that's not a problem as there's all the basic programmable options in the menus that I need.
I think I ordered the wrong 'type' of transmitter as I want the throttle on the left with a centre spring return and the rudder on the right stick, a quick strip down and butchers at the internals has shown that I can transpose the stick/pot/gimbal assemblies very easily to suit my preference and swap their functions in the menu options.
The standard of construction is remarkably good for such a low cost piece of technology, speaking as someone who has seen and worked on the insides of innumerable bits of broadcast TV kit.
The transmitter has four assignable switches, I'll use two for the lighting circuits, and one of the two pots will be ideal for my rotating searchlight.
The rudder servo is a Futaba S3003 standard servo with plastic gears, I think anything more would be overkill.
I also bought a couple of Turnigy R/C switches to control the lighting circuits and NiMh battery packs for the receiver and lighting supplies as I didn't want to feed these from the main batteries.
I cobbled it all together on the bench for a quick test and it all works just as expected including running up the motor through the ESC, I have a programming card for that and I will need to set up the ESC before it goes in the water.
The main battery packs are two 9.6v 5000mAh NiMh packs by Vapextech which are wired in series, they sit on a bearers on either side of the propshaft aft of the motor, the receiver battery pack sits between them and all will be strapped down with cable ties.