capabilities                      prototype                   quote                     
Texcast Inc.
706 Lehman
Houston, Texas 77018


Rapid Prototyping, Rapid Production, Direct Manufacturing and Rapid Manufacturing Metal Parts

Using several different types of patterns Texcast can produce investment castings for prototype or production.  At Texcast it is very common to use different methods to produce the patterns depending upon the delivery and maturity of design. New designs are often prototyped to allow testing of an actual investment casting. Once this has been done hard tooling is normally built, but not always. We produce many parts using several methods other than hard tooling once parts go into production.

There is not really any difference between rapid prototyping, rapid production, direct manufacturing and rapid manufacturing of investment castings other than which type of pattern is most appropriate to meet delivery, quality, quantity and cost constraints.  There are no set limits as to which process to use based upon the number of parts to be produced. Each part configuration is unique and must be reviewed by foundry to determine the most appropriate path.  Guidelines are: 


           Hard Tooling

Delivery of first article samples, 4 weeks (very simple parts) – 12 weeks (normal complexity) – longer for complex  or parts requiring ceramic core tooling

Delivery of production, 2 – 12 weeks after First Article approval.

Highest tooling expense

Lowest investment casting pattern cost

Hard tooling will have the longest life. Simple tooling will last for hundreds of thousands of parts. Complex tooling with slides and cores will wear over time but can generally be refurbished. This is not normally necessary for many years.

Yields the best surface finish and most consistent dimensional control.

           Soft Tooling

Delivery of first article samples, 3 – 6 weeks

Delivery of production, 2 – 12 weeks after First article approval

Soft tooling is less costly than Hard Tooling

Pattern cost is higher than Hard Tooling. This is because the tooling will cycle slower due to the poor thermal conductivity of mold material

Life of soft tooling is limited. Life will depend upon the complexity of part. The more complex the shorter the life

Surface finish and dimensional control is not as good as Hard Tooling

A single SLA (stereolithography) or Objet pattern is generally used to make the tooling

      Patterns made from individually produced patterns

Each casting produced will require one pattern. This method is generally used when small quantities of investment castings are required for prototypes or rapid production of a few parts. But it is becoming more and more popular to use as the fastest way to produce investment castings where design changes or unknown future requirements allow for higher per piece pricing since no tooling expense will be incurred. Some information about suitable investment casting patterns is in order. To produce investment castings it is necessary to shell the pattern. This involves coating the pattern with a ceramic material. After shelling, the pattern must be removed from the shell. This produces a void in the shell which will be the receptacle for the molten metal. When the pattern is removed from the shell it must be removed completely and without damaging the shell.  Wax is a foundry friendly pattern material.  The wax is removed from shell by heating. This is generally done in an autoclave very quickly.  As the shell heats up the wax in immediate contact with the shell quickly changes state from solid to liquid and is absorbed into the porous shell thus allowing room for the balance of pattern wax to heat up, expand and be drained. Some of the RP, rapid prototype, patterns do not melt and must be burned out of shell. Unfortunately some also expand and can severely crack the shell if not hollow. On thin edges it is not possible to hollow the section and that is where the foundry’s expertise is needed to help chose the most appropriate pattern for your application.

3 Dimensional Printers, MJM, Multi-Jet Modeling

ThermoJet RP, rapid prototype, patterns are the best choice for certain part configurations where thin sections would be a problem to produce a pattern suitable for investment casting, due to problems removing some other types of RP, rapid prototyping, patterns from shell.  Surface finish and dimensional stability is dependent upon part configuration

SLA, QuickCast Stereolithography patterns

Highest quality RP, rapid prototype, patterns from dimensional and surface finish point of view

SLS, CastForm Selective Laser Sintering patterns

Surface finish is rough, about 250 RMS.  Dimensionally of lower quality than SLA patterns. 


Highest quality RP, rapid prototype, patterns from dimensional and surface finish point of view.  Patterns must be hollowed out.

Z-Corp Investment Casting Pattern Material

Surface finish is the roughest of all RP rapid prototype patterns.  Least consistent dimensional stability of all RP, rapid prototype, patterns;  Least costly of all RP, rapid prototype patterns

The most important thing to remember is to get the foundry involved in your design early to allow the foundry to give advice on how to make the part friendlier for investment casting.




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