Design to Production Project Cycle
for Injection Molded Parts

Design to production - molded partsQuote Process & Considerations

The most preliminary question is “will we need 500 to 1000 parts at a minimum?” This is where building a 1 or 2 cavity mold becomes cost effective.

3D printing technology is rapidly developing, so this is just a rough guide of course.

Many customers ask us how the process of getting a plastic molded part made works. The following is the general sequence of events:

It first starts with a 3D design preferably done by a product designer familiar with the rules for designing injection molded parts. Usually this designer is part of an engineering group, either from an independent Product Design Services company, or an internal engineering group within a business.

Typically, such groups have 3D printing access to test fit and function prior to moving toward having a mold built, usually the largest expense.


At this point we need to know the desired material, color, and projected quantity.

The quantity is often an unknown, depending on the future success of the product, however the choice comes down to a smaller outlay for a 1 or 2 cavity mold if the future requirement is unknown. If the product becomes a great success, it can always be re-tooled with more cavities, the math always works out if an unknown becomes tens of thousands per month.


Shadow’s Ridge generally has our Chinese associates do our mold tooling. Gone are the days when Chinese molds were substandard. If we anticipate the mold will be moved here, we have it quoted for US production, which increases the cost modestly, but the molds are made more closely matched to US molding operations.

At this point we have what we need to quote the tooling and production.

When the mold is built, it is tested in China and samples submitted. We generally ask our customers to have some production done in China. There advantages of this are that any “new mold” issues are discovered and corrected by the original mold builders. Also, the customer occasionally discovers important needed design changes which are economically implemented by the original mold builders, occasionally a small design change can make a big difference in assembly ease or product quality. Finally, enough product can be molded in China ahead of the mold being shipped, which takes 2 months but 3 months needs to be allowed in the logistics plan for the occasional customs or land transportation delays.