In the previous blog on “Types of Die Casting Molds” I explained the basics of various molds that are common in the die casting industry. The understanding of what type of mold is being offered by your die cast sources is very important for valid quote comparisons and long term costs associated with mold life and maintenance with high volume die cast parts.
Many purchasers in the marketplace for die castings usually review the price of the tooling offered and do not ask questions regarding the tool configuration, the die cavity steel being used, the method of heat treatment, or if a trim die is being offered in the quote package.
To have a successful product launch it is necessary to review the details of the tooling and how the tool will be designed and constructed.
The customer company, in the person of its engineering and quality assurance personnel, will usually be requested to meet with the custom die caster’s engineering and quality assurance personnel as early as possible to discuss the design and function of the part design proposed for die casting. In many cases this discussion will take place during the quoting process – before the project has been awarded. If the die caster does not discuss design and function details with you, then consider another supplier that will offer the services of design input to reduce overall costs of the project.
They will discuss the design’s function, fit and precise assembly with other components. The die casting process uniquely lends itself to parts consolidation, decreasing the number of components in a product assembly.
Early involvement with the die caster is essential in avoiding expensive corrective steps in later die construction. It can often simplify product assembly and significantly reduce total product costs.
For example, an attached hinge bracket could be die cast as an integral part of the casting. A slight design modification could assure clearance for a close assembly.
The die caster may be able to cast an integral bearing in the part that the customer was planning to press in. Or the die caster may be able to perform a complete or partial assembly operation more economically, such as installing a gasket after painting the casting, and shipping the part ready for assembly.
Premier Engineered Products has in-house capabilities for operations such as pressure testing, machining, surface finishing and subassembly. Our Company is regarded as an invaluable source of expertise in the die casting production and assembly process.
When databases are utilized, quotations for castings are often based on the assumption that any CAD databases provided to build tooling and produce parts are complete, usable and are without need of updating.
Databases may be deemed incomplete and unusable if:
1. The geometry of the part is not physically moldable.
2. The necessary draft and radii are not incorporated.
3. Line and surface geometry are not connected within 0.001”.
4. Parting line is not fully developed.
Note: The database file format may not be compatible with existing capabilities and may require a translator. STL files are usually only used for creation of prototype parts.
Any necessary database manipulation that is caused by incompleteness as described above could add cost and extended lead-time to tooling.
If databases are designed only to nominal dimensions, tool life and casting tolerances may be adversely impacted.
If solid model databases are used for tool construction, they should be accompanied by a limited dimension part print (either paper or database) that contains all tolerancing information and information pertaining to any secondary machining that is to be performed to the part.
The revision control for databases should be as agreed upon between the die caster and customer. During the project launch it is imperative that the 3D model design changes are controlled to avoid building the mold with the incorrect model.
The most important thing for any purchaser of a die casting is to make sure the RFQ is detailed and the quotes collected from potential die cast suppliers are detailed to the point you know what your are purchasing. Buying a die cast mold is a large investment for your company and performing due diligence will avoid costly mistakes later on in the project for your company.
If you have any parts that may be considered for the die cast process please send your prints or files to Sales@diecasting.com
By Leonard Cordaro, President of Premier Engineered Products