Why Not 3d Printing?

Tags: 3dprinting, tech

On the surface, 3d printing is an incredibly appealing technology. To be able to download an object, or draw one yourself, and have it be in front of you in the real world in a matter of hours, without any work on your part and using only tools you have in your home, is like something out of science fiction. This is the promise of real-world home 3d printing. Sadly, 3d printing does not live up to this promise. It's still a useful tool and a powerful technology, but there are serious problems with 3d printing.

Everything on this page is written based on my experience and research around consumer 3d printers using FFF/FDM (filament-based) technology. Everything may not apply to resin-based printers or industrial machines.

Running a 3d printer is a new hobby

A 3d printer is not a machine that you can set and forget, nor one that requires some configuration once and then will continue to function as you as you feed it materials. 3d printing requires constant learning, tweaking, and work. In order to properly use a 3d printer, you need to learn how to calibrate it, how to fix it if it breaks down (and it WILL break down), how to slice a model to get an accurate print, the properties of materials, etc. Using a 3d printer is a constant learning process. A 3d printer is never "just working", it's waiting for you to have to learn another new quirk of the process. And this is all even assuming all you are doing is printing other people's models - designing your own requires you learn not only a 3d CAD package but also the design issues that come with making parts for 3d printing.

This is not necessarily a negative - I've learned a lot through 3d printing that I can apply to other areas of life and to future projects (about CNC motion platforms, electronics, materials, industrial design and CAD, and other things I'm probably forgetting). But you have to be aware that this is what you're getting yourself into with a 3d printer. Most people buy a 3d printer to support their efforts in a hobby - be it cosplay, tabletop games, hobby electronics, or whatever. But by buying a 3d printer, you haven't just bought a tool to help you with your hobby, but also a new hobby entirely in maintaining and using that tool.

3d printers suck at making a lot of things

It's a fairly common misconception among people who don't understand 3d printing that the technology can be used to create basically anything. But like all tools, 3d printers have limits. This is a generalisation (there are tricks to get around most of these), but 3d printers can't create:

Additionally, even for things that 3d printers can handle, 3d printers often require lots of tweaking in the slicer software to get a good quality print of an object. Slicer software is getting a lot better at sane defaults (my printer, the prusa i3 mk3s, prints quite well with the default "0.2mm QUALITY" profile) but more complex objects require more complex configuration.

This is true of CAD models as well. A model intended for 3d printing has to be manifold (a single mesh with no intersecting shells), avoid overhangs, include sufficient tolerance for potentially problematic areas, avoid fillets, be careful with holes, etc. Even if you have a perfect model that takes everything into account, it could be distorted during slicing or printing, and the result would not be exactly as you'd expect. With 3d printing, as with most things, the map is not the territory. The only way to see if a model is correct is to try printing it, which leads onto the largest of the problems with 3d printing: waste.

3d printing makes unrecyclable plastic waste

Image: the waste from a single 3d printing project, the neotrellis grid

3d printers are wasteful machines. Prints can easily fail, leading to unusable plastic objects. A successful print of a bad model will be unfit for purpose, and become scrap. 3d prints are hard to rework post-printing, due to being plastic, and print features like infill. (trying to sand a part down to fit a larger contents? You only have a potential perimeter width, generally 0.8mm, of wiggle room until you hit infill which is no longer solid). Even a successful print creates waste: support material (which is often copious on organic shapes), calibration cubes and sheets, skirts, brims and purge lines are all plastic waste created in the 3d printing process even if your final part is perfectly correct. Some of these (like calibrations) ideally only need to be done once, but others (like supports and skirts) are printed for /almost every single part/ you create. In the course of designing and prototyping the neotrellis grid, over 200g of plastic waste was created in test parts, failed prints, and calibrations. This waste is not recyclable in most of the world, as recycling companies and plants cannot handle PLA (the most common 3d printer filament material). The issue of failed prints can be sidestepped by creating smaller test parts to make sure your model is printable, but these themselves then become waste.

This is obviously an issue from an environmental perspective. A technology that creates so much plastic waste is hardly a responsible one, contributing to landfill. While a single individual creating some failed prints may not be a huge issue in itself (while it should be avoided, like all plastic waste), this issue compounds with the amount of people using 3d printers, a number that is constantly rising as the technology becomes more accessible.

"But PLA is biodegradable!" and other myths

There are some widely held misconceptions around the environmental sustainability of 3d printing, with most centering around the fact that the most widely used 3d printing filament material, PLA, is a bioplastic (created through fermenting plant starches). This is a more sustainable production method than oil-based plastics, and does solve that specific problem of plastics. However, PLA retains the problematic properties of other plastics when it comes to end of life (which most 3d printed parts reach quickly, as they are waste). PLA is not widely recycled, and it is challenging to recycle it, due to contamination risks and quality control issues. PLA producers often advertise PLA as being biodegradable, but this is only the case under industrial composting conditions. Degradation under any other conditions is as slow as other plastics.

Solutions for recycling PLA /do/ exist, including home devices such as the 3devo, but these are outside of the price range of 99.9% of users (the cheapest 3devo is $7450), rendering them practically pointless.

Additional Reading: Why There isn’t a Mainstream 3D Printing Waste Recycling Service

What do I use instead?

If not 3d printing, then what? Well, I have a few suggestions:

I understand that these options may not work for everything (for example, D&D minis or small replacement parts, which 3d printing is great for) but they should be considered before you jump to 3d printing as a solution.

Conclusion

From this page you may think I'm against 3d printing. Quite the opposite - I 100% support home fabrication and Computer-aided manufacturing. It's a wonderful resource to have and one that makes prodution and invention far more democratic. However, 3d prining has a way to go before I'd endorse it as a technology for wide use: