May 2012 Design Tip



It's Never Too Early for ProtoQuote®

By this time, you probably know all about ProtoQuote interactive quotes: they're free, automated quotes for rapid injection moulding that allow you to interact with the material choices, quantities, and design feedback (see Figure 1). The design analysis suggests where and how your design should be tweaked to improve mouldability. For most users, ProtoQuote fits into the design process somewhere after napkin sketches and 3D printing (or other additive prototyping processes) and before the injection moulding of production parts. That's the tried and true methodology, but we'd like to suggest an alternative approach that you might find useful.

Figure 1: Dropdown menus allow you to change materials, A- and B-side mould finishes, and quantities to see the impact on price.

Figure 1: Dropdown menus allow you to change materials, A- and B-side mould finishes, and quantities to see the impact on price.


On your next project, consider uploading your 3D CAD model to get a quote from Protomold before you make your first prototype no matter what prototyping process you plan to use. In other words, whether you start with an injection moulded or machined prototype from Proto Labs, a layered prototype from an outside service bureau, or a layered prototype made on your own in-house equipment, get a ProtoQuote first.


The reason is simple. If you plan to use injection moulding for final production, it is crucial to know your design is mouldable, and the earlier in the development process you know this the better. As we've often pointed out, Protomold injection moulded prototypes will tell you whether your design is mouldable. (There are, of course, other reasons to use rapid injection moulding in your development process-it provides functionality information that you can't get from any of the additive processes-but we understand that the additive prototyping processes can be useful in early stages of development.) What we're suggesting is that you not wait until you're ready for moulded prototypes to get the design analysis that comes with your ProtoQuote. We'd even go so far as to suggest that you request a ProtoQuote even if you have no intention of ever getting a moulded prototype before committing to production tooling!


The benefit for you is that our quoting software can identify potential mouldability issues (see Figure 2), like missing draft or potential for sink, at any point in development. All you need is a 3D CAD model you can upload, and since all of the above processes require a 3D CAD model, requesting a ProtoQuote is fast, simple, and free. In return you get valuable information that could potentially prevent moulding problems or the need to "go back to the drawing board," later. If your part has undercuts, ProtoQuote will find them. Walls that are too thick or too thin for effective moulding? Additive processes won't find them, but our proprietary quoting software with design analysis will.

Figure 2: The ProtoView<sup>®</sup> 3D viewer allows users to view a fully rotatable model of the design and zoom in on potential mouldability issues.

Figure 2: The ProtoView® 3D viewer allows users to view a fully rotatable model of the design and zoom in on potential mouldability issues.


If you plan to use ProtoQuote this way, there are a few things to keep in mind. Along with your 3D CAD model, the software will optionally ask for your resin choice, the number of parts you want moulded, and your preferred speed of delivery. Your model will then be run through the largest compute cluster in the industry, and you will receive, in less than 24 hours, an interactive price quote along with your design analysis. If you aren't ready to order moulded prototypes, you can ignore the quote and go straight to the analysis. Colour-coded markups on your CAD model will indicate potential mouldability issues (see Figure 3). If you will be using the Protomold injection moulding service, these concerns will have to be addressed. If, on the other hand, you are planning to make prototypes using any of the additive-layered-prototyping processes, you don't have to make these changes, but if you plan to use injection moulding for production you'll probably want to address them anyway.

Figure 3: The grey area on the rim of the part indicates an area with zero draft, which may cause issues such as drag marks, or distortion from ejection stresses. This is one of the many design considerations for optimal performance in the injection moulding process.

Figure 3: The grey area on the rim of the part indicates an area with zero draft, which may cause issues such as drag marks, or distortion from ejection stresses. This is one of the many design considerations for optimal performance in the injection moulding process.


Once you have made the indicated changes in your 3D CAD model, you can resubmit it at Protomold.com to make sure you've addressed everything. As development progresses you'll probably want to make one or more injection moulded prototypes to use for functional testing, because real prototypes provide information that CAD models, simulation software, layered prototypes, and even a ProtoQuote design analysis can't.


Get a free quote with design feedback today.


Watch these short videos about ProtoQuote or ProtoFlow (simulates resin flow, predicts pressure and anticipates resin fill issues).