Glow Plug

The content of this wiki page refers to the Exceed Hyper Speed Nitro RC Buggy.

Current Designs

Figure 1 - The engine, with the metal glow plug on top

Our product currently uses a glow plug to ignite the gas in the piston chamber. A glow plug requires the user to heat it with a glow starter which is a key like rod.The glow starter heats up when it is plugged into an outlet. The user then inserts the glow starter into the glow plug to heat the platinum coil in the glow plug.

Possible Redesigns

Spark plugs perform a similar function and are used in full sized cars and other vehicles. Spark plugs work by using a high voltage to send an arc of electricity across a small gap. This spark ignites the fuel in the piston chamber. Our product is a beginner level RC car. It is important for any beginner level product to require the least amount of user input possible while the user becomes familiar with the product and its operation. By replacing the glow plug with a spark plug the combustion process can start without the user input of the glow starter to heat the glow plug. Ideally this design change would reduce user input and reduce the risk of burns associated with the extremely hot glow plug and glow starter. The pros and cons must be considered when deciding whether to implement this design change or not.

• Economically it would be more expensive from a manufacturing perspective to use a spark plug rather than a glow plug. A micro spark plug ranges from around $10 to $25 (sparkplugs.morrisonandmarvin.com/index). A glow plug cost as low as $3 (amazon.com). However when looking at a consumer perspective the glow plug starter, which is not provided with the car and is therefore a consumer expense, cost around $15 with an AC charger (amazon.com). By erasing the need for the consumer to buy a glow starter the producer can justify charging more to include a spark plug in the car.

• The main Societal concern with this improvement is safety. While the addition of a spark plug to replace the glow plug could reduce the risk of burns from the glow plug and starter it could also create some safety hazards as well. A misfiring spark plug could result in an explosion which could damage the car or harm the user. Extensive testing would need to be done on the spark plug/engine system to ensure safety.

• Serviceability can also be an issue. In order for the piston to work the spark plug must be sealed so that the piston chamber is air tight. Spark plugs wear over time so this seal must be easy for users to open and close.