November 2008 Design Tip

Look Sharp

For several years Protomold has been expanding our range of prototypes and production parts we can make by increasing our mould bases and press sizes. At the same time we've been aware of the demand for thinner features and Protomold has begun to incorporate additional technology in our mould making process to allow your parts to be taller and narrower.

For example, we now offer:

  • Thinner ribs with less draft
  • Smaller, more complex features atop tall walls
  • V-ribs for ultrasonic welding

Fig. 1

Fig. 1

In the past, taller ribs have required more draft than shorter ones, but with the new technology, this is no longer always the case. On small parts, we now have the ability to consider less draft on deep ribs and sharp corners on outside edges.

These new capabilities do not apply to all parts. Initially, they will be limited to relatively small parts, approximately 76.2mm by 76.2mm, and 25.4mm above or below the parting line of the mould. Within a few months, we will expand the footprint of parts to which the new technology can be applied. As with many of our capabilities, the applicability will vary based on a number of factors. The best way to know whether they apply to your parts is to submit your design to ProtoQuote®, which will evaluate your model against our most current capabilities.

Once you have received your ProtoQuote, you can discuss your project with our Customer Service Engineers by calling us at 00800 77686665. Our CSE's can help you understand how your part is going to be affected by our process and if there are alternatives within the Protomold's process to manufacture your part.

Bottom line: if you want thinner less drafted features on relatively small parts, give us a try. As always, you can upload 3D CAD models to ProtoQuote at

Speaking of "bottom line", this technology does add some cost to the mould. We do add a mould advisory to your ProtoQuote under our "Other Info" column. You can still design to the "old" Protomold rules for draft, and avoid the added expense. Give our CSE's a call at 00800 77686665, and they can help you out.