This housing half illustrates the general complexity of parts from ProtoMold.


Parts made by Protomold need only a core and cavity. The interactive quote screen lets users change inputs and then watch the price update. The part shown to the upper right would be about $1,995 for up to 25 parts. Average cost is about $3,300.


The quote returns an analysis pointing out undercuts and sharp edges that cannot be produced. In this case, the orange lines highlight edges that will have a radius of 0.016 in.

Engineers with Protomold, Maple Plain, Minn. (, have developed a manufacturing process that turns 3D models into real injection-molded parts in as little as five days. Regular delivery time is 10 to 15 days. Larry Lukis, founder and chief technical officer of the company, and his development team wrote software that analyzes a model, generates a quote, creates the mold design, programs the milling machines, schedules productions, and bills customers. "Parts can be fairly complex even though they are limited to two-part molds," says Lukis. "Software to handle more complex parts will be available soon," he adds. However, the company does no EDM work.

Lukis' secret to quick turnarounds is to mill molds from aluminum rather than tool steel, and software that streamlines the operation. In fact, he says, most molds are being cut within a few hours of order arrival.

The system works like this: Users submit a model in standard 3D-solid formats, such as IGES, SolidWorks, Parasolid, or ACIS. When their interactive Web-based quote returns within 24 hr of submission, it highlights features that might complicate production, such as sharp corners and undercuts. "The machine tool always leaves slightly rounded edges or corners, so that is pointed out to the client. If they can live without details such as sharp corners, we can build the part," says Brad Cleveland, company president.

The quoting system lets designers select a surface finish inside and out, the number of mold cavities, plastic material, quantity, and when they need the parts. "As users make on-screen selections, the quote changes. So users in effect design their own quote," says Cleveland. Should a user ask for a large number of parts that might wear out an aluminum mold, Lukis says they'll just cut another one.