Vosper Perkasa P150 1/32 Scale - Radio Control (R/C) Model (Build Log - Part 17)
This is the seventeenth entry in the build log and relates to Step 17: Main Dynamic System Assembly. In this step, I describe the installation and wiring of the motors and r/c component assembly.
The main point to note is that for three propeller shafts it is necessary to fit some sort of differential throttle control that works in alignment with the rudder operation. The boat turns very well with such a system fitted. I used two micro switches placed on top of the rudder servo, these in turn cut off the power to the inboard engine in a turn, which has a strong effect of increasing the turn rate significantly. See the images below for photo (top) and circuit diagram (bottom). The rudder was moved from its original position to the position shown in the image below, using strong wooden beams as servo bearers.
Click images for a larger view.
Take note also that one shaft runs in the opposite direction to the other two (see circuit diagram).
In addition to the wiring modification, I cut the servo tray in half to allow the battery tray to fit cross-ways in the aft part of the main r/c tray, this has the effect of moving the centre of gravity of the boat rearwards to bring the model to sit accurately at the waterline.
Finally, the flash video, below, shows the end result. This layout is very effective in creating great slow speed maneuverability and control.
Click play to start the video.