When I first encountered the Scalextric 4 Schools competition I was tempted to dismiss it. When I initially viewed the formula it appeared that the size of the cars themselves would not allow deep engineering thinking as they felt too small. Three years further on I am starting to wonder if I will ever plumb it's depths.

From a teaching point of view it is manor from heaven unlike many projects it has been described as being an onion, you no sooner remove one layer then you discover another.

This was one of these good ideas encountered by accident. We had been trying to make tyres for a long time. We initially tried wheelchair and pedal cycle innertubes cut and stretched over laser cut acrylic hubs but this proved to be useless. We postulated many solutions but most died on the drawing board.

When I finally encountered Multibase the solution was obvious and it opened up a whole new level of engineering practice.

At Keystage 3 I would be introducing these additional pieces as future expansion as the basic car build will absorb the students fully without getting into the finer detail of engineering design. However a look at where the project may extend is always inspiring.

At keystage 4 I would first look at the bearing which is almost a brass bead pressed into the acrylic chassis (You need to be using the Boxford Ladder chassis for this to work). The Acrylic chassis will heat up with the friction of racing and after about 4 minutes will start to plasticise and add drag to the rear axle placing additional stress on the motor and gears, it can eventually result in the back end seizing up. Brass bearings like we are using were common in the world of steam engines for over 100 years and with correct lubrication can last thousands of miles under the loads expected by British Rail. I myself have seen ships gearboxes with 13ft diameter gears arrive back at David Brown Gear industries for new white metal bearings with no sign of a ball bearing in the whole unit. Needless to say any modern gearbox would utilise the advantages of a ball bearing unit.

The manufacture of the wheel is very much governed by the shape of the tyre you are going to make the two halves to match each other but it is worth noting at how the diameter of the wheel is slightly larger than the diameter of the hole in the tyre to ensure good friction.

Finally the elastomer - I have found a video about elastomers to help students understand there use it is not the elastomer we are using but shows why they were developed. Elastomers are still relatively new and as such not much information is held on the web. What we are doing is very cutting edge.

At Keystage 4 there are any number of project areas covering tyre shape, tread pattern, removal of bumps or ensuring rotational accuracy. Also removal of dirt or grease before racing (Often done with upturned gaffer tape). The potential improvements to try and gain a racing edge are enormous.