Lego R C Tank



This is the second Lego Radio Control model I have thought of building. It is a tank which could possibly be powered by two or four Lego 9 Volt Motors. As of yet, I have not constructed a working model, but it should be coming soon... Here are some of the ideas I have been throwing around, which will probably be included in the final model;



Basic two motor design (Top View). This allows for a 27:1 gear ratio, which is a little slow, but allows for a tank model to easily climb over various terrain. In order to achieve a better ground clearance, all of the gear reductions shown should be sev eral full-bricks away from the ground, as shown here;




Here is a little look at the wiring system, which requires a new device, controlled by the steering servo which will divert power to the appropriate motors. Actually, this device will deny power to the motor on the inside of the turn, causing the tank to turn this direction. This will make the model steer and react much like a regular cars steers.



This image shows the inputs from the Transmitter, and the resulting actions of the two motors in the tank model. As you can see (for example) in the upper left corner; an input of left steer and forward throttle will make only the RIGHT tread operate in the forward direction (indicated by the blue arrow). This will make the tank proceed forward in a counterclockwise spin.

To achieve this type of control, a small device must be included in the model which incorporates two light switches (Single Pole, Single Throw, Normally Closed) which can be purchased at any local electronics store, and two Lego 9 Volt electrical wires mu st be sacrificed. (Alternatively, four pieces of electric brick may be used with some other wires. The basic setup is shown below;



When the tank is steered to the left, the left button is pressed, opening this electrical connection, shutting off the left motor (and therefore the left tread) and creating a forward, counterclockwise turn.
by Craig Lampe Send E-Mail to the Greek!!
( clampe@mednet.swmed.edu )

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by Craig A. Lampe

revised: November 3, 1996