Sunday, March 23, 2008

Die Cast Truck History

The History of Die-Cast Trucks

Die-cast truck models have existed nearly as long as the trucks they were modeled after. Improvements in industrial die-casting and metallurgy have benefited the die-cast toy vehicle industry since its beginnings in the early 20th century. The purpose and marketing of the toys themselves has changed as well. However, the collection of these die-cast vehicle replicas remains a widespread hobby with ever growing appeal.

Early Die-Cast Trucks

The earliest die-cast toys were marketed in the early 20th century. The first model designs were simple and crude, consisting of metal car or truck bodies with no interior structures or windshields. Vehicle models were cast from a zinc-aluminum alloy called Zamak. The Zamak alloy often contained impurities, and was prone to cracking or degradation over time and with handling. Because of this fact, it is difficult to find die-cast trucks or other vehicle types from this era in good condition. The first manufacturers of die-cast vehicles included Meccano’s Dinky Toys line in England and Dowst Brothers’ Tootsie Toys line in the United States.

The production of die-cast toys all but ceased during World War II as raw materials were being diverted towards the war effort. However the innovations in metallurgy and production tooling developed during the war provided practical benefits to the toy industry in the post-war era. In 1947, Lensey began manufacturing the Matchbox series of vehicles, which would become the most widely recognized die cast vehicle brand in the world. Mattel’s Hotwheels brand arrived in 1968 and challenged the dominance of Hotwheels. Both Matchbox and Hotwheels vehicles were designed on a 1:64 scale.

Marketing and Die-Cast Trucks

In the 1960s, marketers began to develop branded vehicles as advertising. These vehicles would bear a company name or logo, and the goal was to influence the buying power of the parents. In the 1980s, large numbers of adults had begun collecting die-cast trucks as a hobby, and the manufacturers responded by generating more precise replica models of many vehicles, since the adult hobbyist was willing to pay more money than the parent of a child. Larger scale sizes, such as 1:18 or 1:12 were introduced as collectables and marketed towards adults.

While trucks had always been a part of the die-cast vehicle market, they gained a large foothold in the 1970s. Manufacturers such as Matchbox and Corgi released multiple versions of the same vehicles, branded in many different ways. Trucks were perfect items for customization, and many bore the branding of large companies.

The economic downturn of the 1980s saw the disappearance of many of the popular die-cast truck brands. Some of the brand names were reborn within new companies. For example, when Lensey went bankrupt, the Matchbox name changed hands a few times, and is now owned by Mattel, who markets Matchbox vehicles in parallel with its Hotwheels line.

Today, die-cast vehicles fall primarily into two markets: toys geared towards children and precise models geared towards adults. Both markets continue to be strong and new versions of both toys and models continue to be released regularly.

Sources

Wikipedia – Die Cast Toys- http://en.wikipedia.org/wiki/Die-cast_toy
Wikipedia – Dinky Toys - http://en.wikipedia.org/wiki/Dinky_Toy
Wikipedia – Corgi Classics Limited - http://en.wikipedia.org/wiki/Corgi_Cars

Sunday, March 9, 2008

Die Cast Manufacturing Process

The Manufacturing of Die-Cast Trucks

Despite their specialized purpose, die-cast trucks are designed and manufactured in much the same way as die-cast components used for industrial and home applications. From die design through the die-casting and finishing processes, die-cast trucks follow a straightforward path on the road to retail sale.

Designing Die-Cast Trucks for Manufacturability

The first step in the manufacturing process is to design the die for the truck parts. Each part has to be designed for manufacturability so that each part can be properly cast, removed from the die, and has the proper strength to maintain its shape when assembled and handled. Next, a metal alloy must be chosen for the truck parts. Zinc alloys are commonly used because parts can be made with close tolerances with minimal shrinkage after the metal has cooled. Zinc is often alloyed with aluminum to improve the metal’s strength and hardness. Zinc alloys can handle the hot chamber process, resulting in faster manufacturing and cooling times.

The Hot Chamber Die-Casting Process

The die-casting process begins by assembling the die. The die may have multiple cavities for multiples of the same part, or one die may contain different cavities for different parts. The die is assembled with inserts as required and the sprue pin is inserted in the sprue hole in the die. The die is then clamped together to minimize the amount of flash that extrudes out of the seams of the die.

The injection mechanism of the hot-chamber casting machine sits in the molten metal of a holding furnace. The furnace is attached to the die assembly by a gooseneck. The injection cylinder plunger is pulled up, and a port in the injection cylinder opens, allowing molten metal to enter the cylinder. When it is time to cast the part, the plunger is pushed downward, forcing molten metal through the gooseneck and nozzle into the die cavity. The metal flows through the nozzle, around the sprue pin, through the runners and gates into the die cavities. A die may have an overflow cavity to ensure that the main cavities fill completely. The die-cast part is then allowed to cool in the die. The die may also contain a waterline to speed up the cooling process. After the metal has solidified in the die cavity, the plunger is pulled back, and the die can be opened and the casting can be ejected.

Die-Cast Part Finishing

After a die-cast part has been removed from the die, it needs to be finished before it can be assembled into the final product. First, any excess material, such as flash or sprue, is removed from the part. The die-casting process generally produces a good surface finish, so not much post-casting machining is required. After the excess material has been removed and the seams cleaned up, the part can be plated or painted, depending on the function of the part. At this point, the part can be included in the assembly of the truck.