A simple approach
This boat controller uses neither of these methods. It uses two parallel propellers driven by different motors. Each motor is controlled by a separate stick on the transmitter and by powering them differently. Push both sticks forward and the boat will go straight ahead. Push one up and one down and the boat will pirouette.
The kit came with no instructions, but we could build it entirely from the picture – the physical setup isn’t particularly complex and was just a case of screwing the bits of laser-cut acrylic together. The only mistake we made was in wiring up the motor controllers. We didn’t notice that the two propellers were set in different orientations, so to go forward, the two motors need to rotate in different directions. This is to stop the boat crabbing sideways when going forward.
In order to make the controller make sense (so moving the boat forward means pushing the sticks forward), one of the motors needs to be wired backwards. One of the drive shafts was very slightly bent, leading the boat to rattle significantly when running. We can confirm that the electronics will survive the occasional dip in the deep blue, but it’s not properly waterproof, so it’s best to keep it as dry as possible.
This kit contains just the power and remote-control section of a boat. You’ll have to supply the hull yourself. In principle, anything that will float, fit the motors, and ensure the propellers are in the water can work as a hull. It’s worth thinking a little about battery pack placement, though. The motor runs off four AA batteries (though you could easily adapt this to take a different source of power) and this is the heaviest part of the kit. Place it too far forwards and you risk ploughing the bow under water when going forward.
However, manoeuvring in tight spaces required running one motor backwards, and this can suck a corner of the boat underwater if the batteries are too far aft. Because of the angle of the drive shaft, the propellers are actively sucking the back of the boat down when running backwards. This is, perhaps, the biggest issue building a boat from this kit. You could mitigate this, to some extent, by only running the motors forwards and accepting the lack of manoeuvrability this entails.
Following a curved path
This style of steering – with one stick for each motor – takes a little bit of getting used to, especially if you’re used to having a power control and a direction control. It’s effectively impossible (for us at least, perhaps more co-ordinated people might manage) to go straight at anything other than full throttle. Push both sticks all the way and the boat will buzz off. However, holding them both, at say, three quarters always results in one being slightly different to the other and the boat curving to one side or the other. It’s possible to get the boat to end up where you want it, but the route it takes there might not be direct.
If you’re looking to build a simple radio controller boat, this is one of the simplest, cheapest ways of setting up the mechanical and electrical parts of it, leaving you to design the hull however you want (providing it floats). It’s not going to be particularly fast or graceful but, with this kit, you can reasonably get something on the water within a few hours, so for quick, fun, cheap builds, it’s hard to beat.
