So, no revolution?
The main issue lies with raised expectations, build quality, price and usability. So here we go, my list of reasons 3D printing isn’t all you think it’s cracked up to be.
People’s expectations: They’ve seen a 3D printed violin; a crazy shoe, and a wrench (yawn) which actually works, straight out of a printer. A very, very expensive, high-end printer which uses lasers or resins. These people think that they can create objects as well without much input or training, on a machine which costs $800 or less. Imagine you’d lived on a planet that had never seen a car before, and all of a sudden the newspapers start reporting about the car, a vehicle which can do up to 250mph, carrying up to 10 people, and cost as little as $300. All true, but as we know, that’s not the full story.
The name: ’3D printing’ makes it sounds so easy, doesn’t it? Do you think if it were still called ‘rapid prototyping,’ people would be saying “I can’t wait to get a rapid prototyper in my house’?
Strength: 3D printed parts are not as strong as traditionally-manufactured parts. Their layer-by-layer technique of manufacturing is both their biggest strength and their greatest weakness. In something like injection moulding, you have a very even strength across the part, as the material is of a relatively consistent material structure. In 3D printing, you are building it in layers — this means that it has laminate weaknesses as the layers don’t bond as well in the Z axis as they do in the X and Y plane. This is comparable to a Lego wall — you place all the bricks on top of each other, and press down: feels strong, but push the wall from the side and it breaks really easily.
Surface finish: People hear you can print in plastic, so they visualise a plastic item. This is likely to be gloss and smooth. They don’t visualise a matt finish with rough layer lines all over. Many companies offer a ‘smooth’ surface finish, but often neglect to add the suffix ‘for 3D printing’. You can also post-process parts, but this generally involves labour and/or chemicals like acetone (really nasty stuff) and loses detail and tolerance on parts.
Cost: Cost is based on material used, so big things are expensive, and small things are cheap. That’s it. Nothing to do with complexity, and nothing to do with number of parts. The beauty of it is that there is no tooling — this opens up a world of opportunity to the designer, the creator and the hacker, but does it really help people who just want a replacement door knob? There is also no economy of scale, so one item is $X pounds, and a thousand items are $1000s. So, producing anything in bulk that is bigger than your fist seems to be a waste of time.