Protolabs Insight : 3D Printing for Industrial Parts

Transcript

Hi, it’s Friday which means it’s time for another Insight video from me.

Each week we take a look at a different aspect of digital manufacturing. In this week's video we look at 3D printing parts for productions and what you need to have in mind when using 3D printing for production.

Now I’m sure that most of us think of this technology as great for prototyping, but we haven’t actually thought that it could be used for production. True it has its limitations, but you would be surprised to learn exactly how it has been used by some companies.

Did you know for instance that it has been used to manufacture fuel nozzles for General Electric’s LEAP engine, or for cabin brackets for the Airbus 350 aeroplane?  In medicine it is used for patient specific hearing aids and skull, hip and ribcage replacements.

I could go on, but the real question is how could you use it?

Clearly it can be used to produce final parts and if the volumes are low enough then it could be more cost effective than casting or moulding. The great thing is that it opens up a world of complex shapes and geometries that are simply not possible using other technologies.

If you are considering 3D printing for production, then the first question that you need to ask is do you want a plastic or a metal part? 

The number of different materials that can be 3D printed is growing all the time, at Protolabs for example we offer more than two dozen resins and powders.  From cobalt chrome or copper, to glass filled nylon, it’s worth exploring what options your supplier can offer.

Let’s start with metal parts. Direct metal laser sintering, or DMLS, can produce parts in stainless steel, aluminium, titanium, copper and many more metals.  And if it’s good enough for the aerospace and medical industries then who are we to argue?

Your 3D printing supplier should work with you to develop a quality plan that can include processing to industry or customer specifications and provide documents and test documentation.   Test specimens can be built quickly and sent to a lab for validation well in advance of a product launch to put your mind at rest. 

Or you could build the actual parts during the production build and test them afterwards, it’s up to you.

Before you get too excited about the design possibilities available through 3D printing in metal, I should sound a note of caution. Just because the metal is suitable for end use parts, it doesn’t mean that DMLS is always the right process to build them.

The technology uses a high-power laser to melt and fuse metal parts together one thin layer at a time.   Because of the extreme heat used, it needs scaffold like support structures to control warp and curl and these need to be removed afterwards.  This takes time and effort. If your supplier offers alternative solutions, such as CNC machining, then talk through the pros and cons with them.

Moving onto plastic parts, selective laser sintering or SLS is used. Like DMLS it uses a laser to fuse layers of material in a powder bed, but because plastic is easier to melt than metal it is not so energy intensive and the structure will not need any support.  This means that part set up is easier and there is less post processing, making it more cost effective than its metal cousin.

It does have its limitations however.   First, you can only use plastics from the nylon family, although glass and fibre filled materials are also available. Second, it’s only available in layer thicknesses of 0.004 inches. And finally, plastics also warp, so you need to follow the same design practices that improve stability and accuracy for injection moulding, such as uniform wall thicknesses and ribbing on large flat areas.

Having said that, nylon is a great material so it really depends on the functionality that you need.  SLS is great for producing low volume parts where investment in tooling for injection moulding does not make sense, or perhaps as an interim solution while you are waiting for tooling.  And let’s not forget you can design complex parts that are simply not possible using other technologies.

Now before I go, I haven’t talked that other 3D printing technology stereolithography or SL.  While it can produce very accurate and finely detailed parts, it is generally not used for producing final parts.  One reason is that the photocurable resin used with SL is not great under UV light.

 There is a solution to this.  By encasing it in a ceramic filled nickel plating, it will be stable enough to last for years.  Ask your supplier if they offer this option.

Let me conclude by challenging you to expand your horizons for 3D printing. Yes it’s great for rapid prototyping, but go beyond these boundaries and think what else it could do for your production.  It can create complex geometries simply not possible using other processes giving you endless options to improve your products, for example by making them lighter.

Watch other Protolabs Insight videos here.