3D printing is not a new concept as it dates back to the early 80’s where the resin layer by layer was developed. However, 3D printing has only recently democratized, with hundreds of “desktop” 3D printers invading the market at the low-end price range (100~500€). Some of these “low-end” 3D printers are actually capable of producing a fair printing quality upon some minor hardware modifications and fine tuning. Taking this in consideration, do these low to mid price range printers have a place in a research laboratory? Is the technology really accessible to the mass public (especially for those on a budget)? We recently acquired a 3D printer in the lab to print small plastic parts. Below you will find our main motivation behind this purchase.
Academic laboratories (at least in the field of biology) are small and relatively independent entities with regards to their funding situation and purchasing activities. This results in a relatively weak position when negotiating prices with providers because we cannot always order products in large amounts. Furthermore, some products required by specific laboratories correspond to a niche market and only represent a few sales per year. If the market is not large enough, providers cannot order large amounts of a given product in order to drop manufacturing costs. As a consequence, it is not unusual to pay several hundreds dollar for a piece of plastic equipment that isn’t probably very expensive to produce in the first place. An example of these products are magnetic racks, pipette holders and some particular tube holders, among many others.
If we focus on magnetic racks, they can be found from different vendors at a price ranging from 100€ to 600€. Magnetic racks are simple plastic parts with one or more magnets and therefore should not cost more than a couple euro to produce. Magnets (the most expensive part) can be bought roughly for 50 cents and for this price you will get magnets with an adhesive force superior to those found in most commercial magnetic racks. With these numbers in mind, buying an entry level 3D printer (an entry model at ~120-200€) to build a magnetic rack should be less expensive than buying a single magnetic rack and you get to keep the printer. But is it that easy for someone with no prior experience in 3D printing?
There are plenty of great open-source projects for 3D printing laboratory related equipment (https://open-labware.net or http://www.appropedia.org/Open-source_Lab among others). Open source 3D models can also be found at thingiverse (www.thingiverse.com). If you are not scared about technical aspects, you can go much further than just printing simple plastic parts and go for 3D printed microscopes, syringe pumps and other complex equipment. In our case, we decided to start with a relatively simple project to print a magnetic rack.
We found a freely available 3D model at thingiverse (https://www.thingiverse.com/thing:2545948), which looked very well designed and easy to print. We also found magnets from a web vendor (https://www.supermagnete.fr/eng/disc-magnets-neodymium/disc-magnet-diameter-12mm-height-4mm-neodymium-n45-nickel-plated_S-12-04-N). The idea was simple, we just had to adapt the 3D model to fit the round-shaped magnets before proceeding to printing. Unfortunately, the “.stl” format of the magnetic rack file cannot be directly modified to change the structure of the 3D object. We therefore had to transform the 3D model into an object using FreeCad (https://www.freecadweb.org). However, we got into a myriad of conversion errors and eventually ended up at the university workshop asking for help (they have 4 3D printers and are trained in 3D design). After trying to convert the “.stl” file into an object without much success, Denis Le Tourneau from the workshop, decided to redesign the rack from scratch. After optimizing the design to perfectly fit eppendorf tubes and our magnet, we were finally ready for printing!
Unfortunately, the first two attempts at printing were not successful as some parts of the rack collapsed while printing. Denis had therefore to adapt the design in order to include some additional parts for structural support (these would then be removed after printing). This strategy allowed us to print the rack but the support structures were too solid and we actually broke the rack while removing them. Denis, went back to the design board and he finally came up with a successful 3D model to print. After removing the support structures and putting the magnets we finally had our magnetic rack!
In conclusion, I do think that 3 printing is a great tool to have in a research lab and I do see a lot of future applications for 3D printing both in research and in education (you can print and build a fully functional microscope for slightly over 100€!). However, it is not as straightforward and easy as I was expecting. It is not as simple as downloading an .stl file and printing straightaway (at least not for us). Final cost of the rack: 4 euros for the magnets and less than 2 euros (approximate value) in PLA filament. If we add the price of a low-end 3D printer (120-200€) we are still below the price of a commercial rack.
Credits for 3D design: Denis Le Tourneau (Ecole Normale Supérieure de Lyon).
The ".stl" file can be available upon request.
Emiliano Ricci (15/02/2018).
First prototype of the rack with sections for structural support. The structural supports were not easy to remove and, as a consequence, we broke the rack...
Second prototype of the rack, here printed in resin instead of PLA. The results were very convincing but, unfortunately, we ran out of resin during the run. The small spikes that you see on the right correspond to the structural sections that help maintaining the shape of the rack while printing.
Final result printed in PLA and with the magnets on place.