In times past, paper and pencil were the most important […]
In times past, paper and pencil were the most important tools a casting designer had, and the development of a casting was a process that was tedious and time consuming. A paper design was created, the blue print was introduced to the die caster - who teamed up with a toolmaker. Together, a die casting machine was selected, the process and mold layout developed and costs estimated. Quotations were made. The bidding winner gave permission to his to\ol vendor to order die steel and start with mold designing. When finished, the mold was sent to the die caster for a first test. After building it into the machine, castings were made and checked for imperfections.
It was not until this point in the process that those involved got any idea about the quality of the casting. If the casting didn't measure up to the desired standards, changes would have to be made. Different process settings and minor die corrections could be done at the die casting machine immediately. But if the first trial showed that the mold had to be changed, steel had to be ground away and welded back in other places, and that work had to be done at the tool vendor's facility, then, the mold had to travel back and forth between toolmaker and die caster until an acceptable casting quality was achieved. The time between starting the casting design and shipping good castings could take weeks, months or years depending on the complexity and size.
Furthermore, mold designs could - and did - change, even after production had started, and those changes meant molds might have different designs, different ages and wearing patterns, and different casting qualities. In addition to mold changes, variations in production parameters like die casting machine pressures, pouring velocities and transitions, lubrication volumes and locations, solidification, and cycle times changed throughout the casting process.
The never-ending need to adjust, and this ended only when the casting was not needed anymore. Working toward a better casting quality kept a huge team active with involvements of the process engineer, machine operator, mold maintenance and toolmaker, quality office, casting designer, casting machining, even assembly and material planning and handling group.
While there was a time when this type of die casting engineering was necessary, the economic realities of today make it financially unfeasible to continue in this way. But even so, this "engineering" can be found in companies that are struggling their way through tough times.