In the first post in this series on the limitations of 3D printing that create barriers to more widespread uptake by industrial users, the focus was all on costs — capital, consumable and lack of transparency.
This second post in the series looks at two other issues — materials and accuracy / surface finish.
As before, the post is constructed from the views of industrial users of 3D printing technology — people that either contract 3D printing services or work with it daily —people that are in the best position to say it how it is. And so they do!
The materials issue continues to be a limitation for design engineers and manufacturing engineers when it comes to 3D printing for prototyping applications.
Magnus Bombus, once again straight to the point, highlights the need for “true engineering materials” for the spectrum of 3D printing processes. Testing functionality of new products is a key application for 3D printing, one that could grow exponentially if engineering grade materials were available more readily.
This view is backed by Rachel Trimble, who is currently researching 3D printing for her PhD at Exeter Advanced Technologies (X-AT). As a researcher, she lives and breathes additive manufacturing and 3D printing every day. She says, “Higher performing materials would be a big step towards uptake if costs can be kept down. Typical 3D printing materials such as ABS and PLA suffer from being quite weak, which limits their usefulness for functional prototyping.”
I would be remiss not to mention Objet, which has more than 100 materials available for the company’s range of 3D printers. Kudos to them for placing a heavy emphasis on material development. But even with their broad selection, the materials still prove to be limited, according to many users, when it comes to fully functional testing applications.
In reality, applications have to be carefully selected to suit the materials, when surely it should be the other way around.
The functionality that metal 3D printing processes offer satisfies user demands. But they remain cost prohibitive (which takes us back to the original post) for most prototyping applications.
There is always a trade-off. It was true between processes when rapid prototyping first emerged, and it is still true today, 25 years later. Which leads nicely to the next issue — the greatest trade-off of all.
Accuracy & Surface Finish
All of the respondents to my question quoted accuracy and surface finish as being major issues. The problem is that high accuracy is possible with some of the 3D printing processes, which quite legitimately boast extremely fine, impressive tolerances, but the parts that these processes produce are extremely fragile and next to useless for functional testing. When strength and robustness are built into the parts, surface finish is sacrificed and requires specific skills and many man-hours to finish the part to acceptable levels.
Kevin Quigley and Russell Beard both took the time to expand on this in some detail, and I believe that their comments are reflective of many opinions out there.
Kevin says, “I fail to get excited by parts that look like they have been laser cut from sheet and stacked. Likewise, I fail to get excited about perfect parts that are so fragile that they cannot be handled for long without warping, marking or getting damaged. I'm after SLS robustness with Viper or Objet surface quality.”
Russell’s perspective comes from a different direction, but pertinent just the same. He is looking for vendors to “Stop making magical things! At the various trade shows I’ve attended, all we seem to see are bicycle chains, figurines, skeletons or 'magic gear trains' ... all of which are lovely but utterly irrelevant to me. I want to see something related to my industry, showing me things like structural integrity, surface finish (before and after it’s been 'finished by hand'), color and opacity, ability to take other surface treatments and ability to accept inserts and screw threads.”
Until this particular trade-off is resolved, the applications for 3D printing will remain relatively limited, and alternative tools for getting the job done — more quickly and efficiently — will always win out. Why wouldn’t they? This is not to denigrate where 3D printing works — when it works it is spectacular— but for greater adoption, this is a fundamental issue that still needs to be addressed.
In the final posts in this series, a couple of other 3D printing limitations will be addressed: input (e.g., 3D data), full-color capabilities, and some more off-the-wall user observations.
Check back. It’s not to be missed.
<< Part One | Part Three >> | Part Four >>