Would You Choose 3D Printing Over SLS On Your Next Project?

Here‘s a quick comparison of the two:

3D printing is far cheaper than SLS printing and takes 1/5 of the time to produce but what are the advantages of one over the other?

 

Whilst 3D printing is great for massing models, SLS is perfect for fine detail and moving, functional parts. It’s important to consider what exactly you’re trying to communicate with your model, so SLS isn’t necessary the best option for every model.

3D printers tend to use plaster infiltrated with wax whilst SLS uses a polyamide (nylon) which is what achieves the finer detail. You can produce RGB coloured models by 3D printing, but begins fading after 1 year, whereas, SLS prints are generally white (at the moment) which tends to oxidise over time and usually starts appearing yellow-y after 6 months. Material choices are expanding for rapid prototyping with lots of contemporary jewellery companies now adopting these methods and printing in metals too (but that’s a whole new topic)!

So here’s a comparison of suitable and non-suitable geometries for 3D Printing vs. SLS

Suitable geometries for 3D printing:
Aesthetic models
Colour analysis models

Unsuitable geometries for 3D printing:
Dense volumes with small joints
Small wall thicknesses (<2mm)
Long thin components
Trapped volumes

As a general rule for 3D printing, as you increase the length of a model over 20cm, you should look to increase the wall thicknesses to maintain the strength, and you can also think about building in parts rather than all in one go. Allow tolerances of 0.9mm when building in parts, so that they fit together on assembly.

Another tip is to create a solid core when building the geometry, to give extra support. Whilst complex aesthetic geometries are achievable, note that fine surface detail is only possible onto solid parts.

Suitable geometries for SLS:
Small wall thicknesses (1mm)
Fine detail
Functional parts that have motion capabilities (0.3mm clearance)
Complex geometries 
Free-form shapes

Unsuitable geometries for SLS:
Long thin columns
Large flat areas

The larger thermal distribution during building and cooling tend to warp the geometry due to the cooling and shrinking of material at different stages of the process, so avoid flat parts greater than 150 x 150mm. If you do have large flat surfaces, create a support structure.

As a general rule for SLS printing, as you increase the length of a model over 40cm, you should look to increase the wall thicknesses to maintain the strength. You can build far more complex structures and free form shapes with an SLS printer than any other manufacturing or modelling techniques today.

I’d love to know about your experiences with rapid prototyping, what will you use on your next project?? And with the fast-paced advancement of technology where do you think the industry is moving towards??

I know robotics and A.I. are big topics at the moment...