In case you haven't heard, rapid injection molding can now support simple undercuts in your part design. The details of what we mean by a "simple undercut" can be found in an updated version of the Protomold Design Guide, but in summary our definition of a "simple undercut" is as follows:



As you are probably aware, undercuts in your part design are implemented through the use of what are called "side actions" in the mold. The animation to the right illustrates how a side action can be used to implement a through-hole type of undercut, and the following table describes the maximum dimensions of the side actions that the Protomold process can currently support.



Due to mold size constraints we can have up to two side actions per part. As always, your ProtoQuote® will identify an undercut and let you know whether or not a side action can be used to accommodate it.

However, we can handle some pretty interesting geometries within these constraints (see illustration), so feel free to leave in some of those undercuts in your next part design.

You can visit the Protomold Design Guide for other helpful Rapid Injection Molding design information.

The Fall issue of the Rapid Injection Molding Journal will include a review of a book on designing injection molded parts. We're thinking about doing something similar in the spring issue for material selection, and would appreciate your response to this survey to help us decide if this would be worthwhile. Let us know what you think, and we'll include the results in next month's Rapid Injection Molding Design Tips.

What level of expertise do you feel you have in the area of selecting the best injection moldable thermoplastic resin for a given design? Expert : I could write a book on it. Knowledgeable : I could review a book on it. Intermediate : I have read a book on it. Novice : I could use a book on it.

Please suggest any ideas you may have for future survey questions. Just e-mail them to us at marketing@protomold.com.

We asked "Quality, Price or Speed - What matters most from your prototype parts supplier?" The responses of the approximately 250 people that replied are graphed in the pie chart. It appears that the general theme is that quality matters most with speed and price coming in as second and third priorities, respectively. So it looks like "Real Parts. Real Fast. Real Savings!" is more than just a slogan - it actually reflects the value our customers put on their ability to get parts made in the desired resin, delivered in days (not weeks) and at a price much less than is typical for injection molded parts.