Crimp Failure at Braid Contact on Scalextric cars from 2016 onwards

Introduction

For a scalextric car to operate the electrical current must flow into and out of the car. That's two discrete electrical connections. To do this the slot rails in the track are the two conductors. The electric current connects to the car via the flexible woven braids fitted to the guide blade, then to the braid contact plates and then through wires to the motor. The rotation of the guide blade for corners and the like is managed through the use of the flexible wires.

The wires need to be securely fixed to the braid contact plate to make the electrical connection and to withstand the regular rotation of the guide blade.

Recently (we believe sometime in 2016) Scalextric introduced a change in the way the wire is crimped to the braid contact plate. This is the silver coloured plate that makes contact with the braid. There is a very serious problem with this new design of crimp.

There is insufficient length to the crimp fingers to fully secure the outer insulation of the wire. With the action of the guide rotating over time the wire pulls out of the crimp. This breaks the electrical connection between the wire and the braid contact plate.

Once the crimp has failed the Scalextric car stops on the track.

Scalextric G38 round guide blade
Damaged Scalextric crimp to wire

Here is a close-up picture showing the failed condition. As this is a design based problem the repair is not as simple as it might appear.

Option 1. Simply re-make the crimp. This will last for a short while until the crimp fails again.

Option 2. Just crimp onto the conductor wire strands. This will last for a short while until the wire strands break through the action of metal fatigue.

Option 3. Solder the wire to the braid contact plate. This doesn't work as the latest braid contact plate is plated in a material that doesn't take solder. There'd also be the strain relief problem.

As shown in this picture to make the electrical contact the insulation is removed and the end of the wire strands are tinned with solder and bent back over the insulation. That's why the electrical contact fails once the crimp fails.

As this is a design based problem the solution must also be design based. That means a new design of connection.

Scalextric wire connection
Replacement Scalextric wire connection

The solution is to use a new braid contact plate made from a slightly stronger steel that is plated with a thin layer of brass. This will take solder.

To overcome the lack of strain relief with this soldered solution a short length of ultra-flexible silicon wire is used. This wire consists of 128 strands of 0.05mm diameter copper and a silicon insulating layer.

This is flexible enough to easily withstand all the movement of the guide blade.

Here is the repair complete in the Scalextric car. The original green and yellow wires are shortened to make the room for the silicon wire tails. The joints are soldered and a length of insulating tape covers the exposed joint.

We freely admit this isn't pretty but it does use the right materials in the correct Engineering environment.

Stronger brass plated steel braid contact plates. Solder joints. Ultra-flexible wire where the wires are needed to move regularly.

Scalextric car repaired

About the author:

Gary Harding has been working with Scalextric cars for over 35 years and now operates Scalextric Car Restorations in the UK. Scalextric Car Restorations is a Worldwide internet based business that offers for sale high quality Scalextric cars and Scalextric parts from the 1960s to the present day. All the restoration work is carried out to the highest standards with the highest quality parts available. Only the best cars are selected and the final result is a car that is genuinely like new.

Further help and advice relating to this article or Scalextric cars in general can be found at:

http://www.scalextric-car.co.uk