Q What are the easiest ways to cut costs when I am designing a part for 3D printing?
Tasos: There are a number of basic things that you can do to optimise your design so that it prints easily and reliably.
Many of these basic rules are the same as they are in injection-moulding projects – use gradual transitions, avoid sharp corners and watch out for tall, unsupported walls. This will make things flow better and look good, so there will be less intervention from engineers and your cost will be lower.
But if you are producing final parts using 3D printing you need to remember what it can achieve. You can also design organic shapes to cut costs using honeycombs, matrices and holes to save material and processing time.
Q Is it always a good idea to use less material?
Tasos: It’s generally a good idea if you’re going to be 3D printing for your finished product. If, however, you are using it for prototypes then you also need to think about what is possible using the final manufacturing method.
Carrying out a manufacturability analysis early on in the design cycle can ensure that what you prototype using 3D printing can still be produced when it comes to manufacturing, which will save you a lot of money later.
Q Is there anything that we should try to avoid?
Tasos: Ideally try to avoid any secondary operations, as these all add to your cost.
This is less of an issue with selective laser sintering – or SLS – as this technology generally doesn’t need much in the way of post-processing. Direct metal laser sintering – DMLS – though, often involves scaffolding structures to prevent warping, and these need to be manually removed after the part is printed.
Even then, however, you can cut down on the number of secondary operations by considering your part’s geometry. So, for example, try to avoid T-shapes with big arms, and overhangs, as these need a lot of supports. If you do need to include those kinds of shapes you might be able to change the orientation, so, instead of printing a T-shape standing up, turn it upside down.
Another thing to avoid is over-tolerancing your parts. While you can specify incredibly precise dimensions, think about what you actually need. If you aim for something that is more accurate than you need this can force your manufacturer to build your part with thinner and thinner layers, which increases the build time and the cost. Sometimes we might even need to use secondary machining operations to get things within the tolerance we were given – again this all adds to the cost.
If you need to achieve small tolerances and a high degree of accuracy it is possible, but, ask yourself whether you need it first.
Q Having covered some of the don’ts, are there any does that we can design to save costs?
Tasos: Most importantly, remember what 3D printing can achieve for you and don’t lose sight of what you want.
3D printing can save you lots of money beyond those upfront costs.
With a bit of creative thinking, you can print fewer pieces and take advantage of features that would be impossible with traditional manufacturing techniques, like internal passages for wiring or cooling. And remember that you don’t need to pay for moulds and tooling either.
And think about how much you might save on shipping costs if you can halve a part’s weight. It might not show up in your manufacturing costs but it will save your company money.
So, think carefully about everything involved and you’ll be able to take advantage of everything 3D printing has to offer and make some savings that are simply not possible using other manufacturing processes.
For further information, please visit www.protolabs.co.uk
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.