Metal Die-casting is not exactly the first process that comes to mind when product development and prototyping is mentioned. This is because of the versatility and wide availability of options like 3D printing, CNC machining and urethane casting. That being said, metal die-casting solutions can be used in product prototyping across many industries using numerous alloys and newer techniques.
Prototyping through metal die-casting allows customers to check the parts specifications, need for tight tolerances, wall thickness evaluation and even product functionality. There are 7 top methods for prototyping with metal die-casting. Here’s a run down of these methods and when best to use each solution.
1. Spin casting
Spin casting in a die casting prototyping method that uses centrifugal forces to introduce the metal die into a rubber mold. This technique works with metal alloys that have low melting points, using the spin casters to deliver the desired shape and geometry of the die casting without compromising on strength and quality.
Spin casting is ideal for prototyping 10-100 parts that have complex geometries to be delivered in strict timelines. The process can help engineers evaluate the fit and design of the part during the product development process. Depending on how complex and the number of parts required, spin casted parts can have a lead time anywhere between 7 days to 3 weeks.
2. Single cavity prototyping
Single cavity prototyping is a qualitative die-casting process engaged when there is a need for extensive material testing. Single cavity prototyping is very flexible, allowing for post-production design changes even after the prototype has been manufactured. This is extremely beneficial considering that over 70 percent of production dies will require at least one adjustment after it has been made. It also allows for critical evaluation of cosmetic and functional characteristics.
Another benefit of single cavity prototyping lies in the ability to use the original die insert in the final manufacturing stage as well. The downside of this method, however, lies in the cost and time involved in manufacturing the dies.
3. Gravity casting
Gravity casting is the most popular method of manufacturing die-casting prototypes. The gravity casting technique houses most of the strategies used in plaster molding and investment casting strategies. It is a cost-effective alternative to single cavity prototyping and generally has a faster lead time too.
Gravity casting produces die casting prototypes that are strong, reliable and less porous. The downsides may lie in the lesser precision across dimensioning and inability to achieve very thin walls.
4. Steel process
Steel process refers to the use of rapid prototyping methods such as FDM, SLS or Stereolithography along with die-casting. The process involves the creation of a master pattern or model using 3D printing to make H-13 steel dies with pressure die casting. The die casting rapid prototyping method is quick and affordable, delivering prototypes in 5-8 weeks. The speed of making the die-casted prototype is dependent on the part’s complexity.
The steel process is suitable when looking to perform detailed and thorough evaluation of your prototype before investing in extremely detailed dies that will serve your mass production run. They can also help you manufacture up to thousands of parts as bridge production units. The downside of the steel process is its unsuitability for projects that have tall or thin standing details and those requiring cast-in-water lines.
5. Investment casting
Investment casting is the recommend approach for die casting projects that requires exact replica prototypes. This method of die-casting prototype emphasizes on the prototype’s function and design. It is ideal when looking to make prototypes that will look, feel and act just as the finished product. The tolerance, strength and function of this die-casting method will not be compromised, making it ideal for rigorous testing and on-the-go evaluation.
Investment casting is great for low-volume metal prototypes. The leadtime can be accelerated through a number of 3D print processes, eliminating the need for building a hard tool. The incorporation of 3D printing also helps to achieve complex geometries and lower cost.
6. Plaster mold prototyping
Plaster mold prototyping, also referred to as Rubber plastic mold casting (RPM) is a die casting prototyping method that works with stereolithography to deliver prototypes in as little as 7 days. The concept is similar to the gravity-based casting, with the compatible materials zinc, aluminum and magnesium alloys.
As is the case in single cavity prototyping, plaster mold prototyping allows for quick and simple changes to the part geometry and design. Inarguably, the best advantage of this technique is the low cost of production, with prototypes costing no more than 10% of the original production die estimates. It is also very good for prototyping parts with complex geometries. Plaster mold prototyping is best deployed when you need volumes higher than a couple of thousands but lower than what justifies hard tooling cost.
7. Machine from similar die casting
This die-casting prototyping solution entails the creation of new product prototypes from existing die casting that have geometries and size resembling the new prototype to be made. This method is particularly useful when looking to make several units of similar product prototypes like gears, bearings, screw-machined items and the likes. The advantage of machining from similar die casting is the optimization, material and cost savings that comes with using existing die castings. The downside, however, lies in the restriction of the prototype dimension and shape to the form of the existing die casting. Also, you can expect to lose some of the thick, dense outer layer that a freshly produced die casting will usually have.
Which prototyping process is right for me?
While there are options to choose from when investing in die-casted prototypes, Firstpart can help you optimize your production and choose what is best for you. The ideal process depends on a number of factors including but not limited to budget, material, lead times and nature of prototype testing to be done. Please click here to get in touch with one of our experts and determine the best process for you. Firstpart will also provide you with free quotes and design suggestions on your next project right away! Work with us and allow us to manage your prototyping needs and help you transition from rock solid prototypes to excellent die-casted products.
