When using cast urethane, it is important to ensure that your part is designed properly. If not, then the part may not mold properly, thus jeopardizing your part functionality and lead time. But do you know what some of the major design pitfalls are? Or what the major guidelines are you should follow?
Here are 5 simple design guidelines for you to follow.
The minimum wall thickness for cast urethane is .040-.050”. Most parts on average have a wall thickness ranging from .080”-.160”.
Although it is more critical for injection molding, draft is not as a big of a concern for cast urethane. At least one degree of draft is ideal for cast urethane, certain parts can be molded without draft. Although, if your intention is to injection mold the part, then design the part as intended for production.
Use at least a 0.125” radius in corners in order to increase part strength and help material flow in the mold. In addition, use at least a .060” radii in the corners of bosses. This will reduce wall thickness, yet still retain the part strength.
Lettering & Logos
Cast urethane can mold both raised and recessed lettering. Regardless of which one you choose, make sure that the lettering and logo is at least .040” thick and raised/recessed at this same measurement.
Tolerance & Accuracy
Part tolerances for cast urethane are +/-.010” for the first inch, and +/-.005” for every inch afterwards.
By following these guide lines, you will be able to have your parts casted with better accuracy and less scrap. Thus allowing you to get your product to the market faster. Have an upcoming project? Feel free to contact us to see how we can help you. Don’t have an upcoming project? No worries, feel free to gander at our other resources like our handbooks and photo libraries.