the starting point...

What an extraordinary idea! I thought, as I listened to the fellow - who was, in a  couple of months, to be my new partner on an exciting new venture.
Then, he brought out the set of Lawn Darts.

‘What I want you to do,’ he said, ‘is to look into the possibility of producing our own design.  Something we can manufacture in large quantities, but in very durable materials so that people buying it will have confidence that the product will last for many years.’  I like a challenge, and I knew I had the confidence and skills to do this.  It would be very different to what I have done in the past, but the prospect of getting it right  excited me.   I wanted whatever I made to be of the highest quality.  I had spent nearly the last 20 years in engineering and manufacturing in England, so I knew exactly how to achieve this goal and knew where to start.

In Manufacturing, working on a variety of projects, it is quite normal to get to know engineers from all walks of life and engineering sectors.  I believe I had encountered more specialists than most would in a lifetime! I meet many different people who contribute a whole range of different skills and knowledge, and you never forget the good engineers you have worked with so that you can call upon their specialist services again in future. It’s a customary practice among people in the industry.

I set about contacting colleagues whom I had known for many years, that I could trust and work with. I was met with the enthusiasm I had learned to expect from engineering colleagues.   The specialist fields I needed were in Plastics and Plastic Injection, CAD CAM machining, Rubber Products, Tool Making, Cold Forging, Packaging and Fasteners. The research I did was very useful, stimulating and fun. Now it was time to get down to details.

the plastic flights...

A quadrant of four fletchings was considered best, unlike the three found on arrows or crossbow bolts, since the airspeed of the darts was going to be relatively slow. This would enable the darts to remain stable and accurate through flight. A slight twist in all four flights, causing the dart to spin through the air, would further enhance its stability - a feature borrowed from archery.  It was necessary to create a long tail so that the user could hold the dart comfortably.

The section thickness of the flight - 1.4mm - was made as thin as possible so that the plastic could be injected without causing scrap, without compromising the structural strength.

Finally, it was thought it should be possible to detach the body from the head, which we achieved by incorporating a screw-in head. In this way, different weights could be used for the head, or a different coloured flight might be purchased to suit a user's needs.

the body...

It was thought most important that the metal used for this component was both attractive and easy to manufacture. We chose brass. Brass is corrosion resistant, so that the dart would continue to look its best for many years with only a little cleaning. The shape of the body was designed with safety in mind. It has no sharp edges. It houses both plastic thread on the flight in one end and the spigot in the other, locked together. A shock-absorbing washer separates the two parts, protecting the thread of the dart flight in the event of the dart hitting a very hard surface.

the spigot...

The spigot was made from Stainless steel, because of its corrosion resistance and compatibility upon direct contact with brass. Various lengths were tested. The best results for striking home was the 55mm long spigot, which allowed 45mm of shaft to stick into the ground. An alternative spigot made from polypropylene is also available.

a note from the design team...

We hope you find this product very enjoyable to play with, but we recognise that the darts are a relatively new product. Every effort has been put in to make these darts both safe and practical to use. However, should you have any comments that you might think will either improve the performance, or compliment the game, we would welcome your correspondence.

Genesis of a Game: Beginnings and the Engineering Process
Jesse Brough. Technical Director