Lego Mini Cooper RC Conversion with SBrick

Last time, I used a cheap RC car components to do the conversion.  By knowing the SBrick, a Bluetooth device that can control 4 Lego motors through your smart phone, I purchased one SBrick and one set of Lego IR remote control with two M motors.

The conversion is mainly in three parts:

1.  The Battery Case and Rear Drive – by moving the rear seat one block forward, I could have enough room for the Lego 8111 battery case.  The driven motor was installed in parallel so as to provide room for the battery case.

2.   Front Steering & Return-to-centre Mechanism – most of the conversion will use Lego 88004 servo motor, when cutting off the power, the shaft returned to centre.  As I was not going to invest an expensive servo motor, I searched the Internet and found lot of return-to-centre mechanism to consider.  It consists of a few Lego block and a rubber band. The front steering consists of a linear tooth gear and round gear.

3.     Position of the SBrick – as it is not so big, I could put it in the front compartment.

To look nice, I added a pair of LED front light as well.

The test drive revealed two dissatisfaction.  Due to limited room inside the front wheel compartments, the front steering angle was small thus resulting a larger turning radius.  When controlling two movements through the SBrick, the movements were slow.  It might be caused by small batteries inside the compact battery case, AAAs instead of AAs.

As the SBrick is quite expensive, the price is twice of one set Lego IR remote control, I later changed it to Lego IR remote control.  As the IR received is higher than the SBrick, I needed to modify the front bonnet.