The new RC Tracked Racer is currently the only way to obtain the Lego infrared (IR) transmitter/reciever remote control in shops. I picked it up yesterday as it’s been released long enough to be discounted.
It’s quite a nice design, the battery box is mounted low and centrally. Each track is driven by it’s own medium motor, one mounted forward and the other rearward. The car body flips forwards to allow good access to the battery box switch.
The build was a pretty straightforward Technic build. I’ve never used these track pieces before – they feel like they are made out of a harder, shinier plastic than the other pieces. That would make sense as this is a set likely to see hard play, including outside. Along with the new track pieces, I did have any of those white Tread sprocket wheels. The only other tread links I have are for the Compact Tracked Loader and I’m pretty sure those links wouldn’t run on these wheels.
Power Functions IR Remote
I’ve used the Lego Power Functions motor and battery box before. If you haven’t seen these, the connections are interesting. Because it’s TLG they have to be snap together and have studs. This is accomplished by having two studs and a special male/female stackable 4 wire connector as part of a special 2 x 2 plate.
The battery box has a forward/off/reverse switch on it which just reverses the polarity of the voltage to change the motor direction if the motor is connected directly to the battery box. This current is carried on the C1 and C2 signal wires.
The situation is a bit more complex when the IR receiver is plugged in between the battery and the motors. The first thing is that there is two outputs, so two devices, in this case motors, can be attached. Those two outputs are now controlled by the twin ‘joysticks’ on the IR remote transmitter. Each joystick is spring centred with a forward and reverse position. The outputs are not proportional – just forward and reverse at the full voltage. This is particularly notable in a model like the Tracked Racer – it goes forwards full tilt, backwards full tilt, turns left, turns right, or manically spins in place.
Both the IR receiver and the remote have a ‘channel’ selection. These need to be matched for the system to work, but allow four pairs of receiver/remotes to be used simultaneously. The IR seems to only have a range of five or six meters, and when I was playing with it, patches of full sunlight caused problems.
Little sliders below the joysticks allow the direction of each of each output to be reversed. When I first tested the RC Tracked Racer, I had to hold one stick forward, and the other back to get it to move forwards. Changing one of th set sliders fixed that problem.