Home > Engineering Information > Engineering Support > Rapid Prototyping

Rapid Prototyping

Signicast offers complete prototyping capabilities and can produce parts in as little as a week. Depending on your requirements Signicast can utilize manual tooling or Stereolithography. Manual, low cost tooling is utilized when more than 40 parts are needed or if the part needs to be production intent in terms of dimensional accuracy and part solidification is critical for performance testing. The Stereolithography or SLA process can be used on low volume requirements and or when “form, fit and function” are the desired results. The SLA process does create a stepped surface finish and it is harder to control some of the tighter tolerances that may be required for a production component. There are alternate methods to creating investment castings without needing hard tooling depending on your requirements. The best prototyping option to pursue is dependent on the complexity of the component, performance, and the quantity of pieces required.

There are alternate methods to creating investment castings without needing hard tooling depending on your requirements. The best prototyping option to pursue is dependent on the complexity of the component, performance, and the quantity of pieces required.

In our experience, the most effective options to prototype investment castings are Rapid Tooling, Machined Wax Patterns, SLA, and Multi-Jet Modeling.

Rapid Tooling
This process involves the construction of hard tooling without the automation of a production tool. In many cases, this tool can be upgraded for use as a production tool, saving cost versus building separate prototype and production tools. Based on our experience, this is the best prototyping option for most parts.
1. Economical for unlimited quantity of prototypes
2. Tool costs: very low
3. Part costs: very low
4. Lead time 1-6 weeks
5. Economical with any part complexity
6. Prototype is a true representation of a production part
7. Standard investment casting tolerances and surface finish are achievable
8. Can sometimes be upgraded to a production tool
Stereolithography (SLA or STL)
This process uses a CAD database to create accurate models of patterns that are then used to make:
1. Silicon rubber, epoxy, or metal molds for wax pattern injections
2. Individual direct patterns, called "quickcast" patterns, which can be assembled to the tree and run through the casting process.
  1. Economical for quantities of up to 40 pieces
  2. Tool cost: low to moderate
  3. Part cost: moderate to high
  4. Lead-time: 2-4 weeks
  5. Economical on complex shapes
  6. Prototype is a reasonably close representation of a production part
  7. Part size is limited to 10" x 10" x 10"
  8. Addition of .005 inches per inch to standard investment casting tolerance is typical
Multi-Jet Modeling (3D Systems Actua)
This process uses a CAD database to create accurate models of individual patterns that are then assembled to a tree and run directly through the investment casting process.
1. Economical for quantity of up to 40 pieces maximum
2. Tool Costs: None
3. Part Cost: Moderate to High
4. Lead Time: 2-4 weeks
5. Economical on complex shapes
6. Prototype is an excellent dimensional representation of a production part
7. Good surface finish
8. Part size is limited to 10" x 8" x 8"
Machined Wax Patterns
Signicast can supply a machinable grade investment casting wax for customers to machine into the wax-to-part shape desired (Signicast will supply dimensions to accommodate shrinkage in investment casting). These machined waxes are then assembled to a "tree" and run through the normal investment casting process.
1. Economical for quantity of up to 10 pieces maximum, unless the shape is simple
2. Tool cost: none
3. Part cost: low
4. Lead-time: 1-2 weeks after receipt of machined waxes
5. Economical on simple shapes
6. Prototype is a reasonably close representation of a production part. Detail and tolerances are directly dependent on ability to machine waxes