Introduction
At maxSIMhealth, we’ve been playing around a lot with the Ultimaker S5 3D-Printers to support our graduate research work, which focuses on the use of additive manufacturing and novel design protocols to create simulation models that strike a balance between cost, functionality, and realism. Along the way, we have picked up a lot of tips and tricks that have helped us create affordable simulations used for training clinical skills and we would like to share some of these with the simulation community.
Filament
There are many materials that can be used for 3D-printing, however, the one that we have been primarily using at the lab is a type of plastic called PLA which stands for Polyastic acid. This material is great because 1) it has low-toxicity and comes in soft and hard forms, 2) it is easy to print with, and 3) it is inexpensive. This makes it ideal for a variety of applications, such as creating small-scale prototypes of simulators. Other plastic filaments we use are TPU (thermoplastic Polyurethane), which is a flexible filament, ideal for printing cartilage, as well as PVA (polyvinyl alcohol), a water soluble filament that we use when printing supports for our complex models.
Once we get our hands on some filament, we’ve realized that it is important to store. Specifically, filament needs to be put into a sealed plastic bag with desiccant when not in use as the filament can absorb the humidity in the room which will ruin it. Filament has a shelf life of anywhere between 2 months and a couple of years. So, when your filament has become brittle and snaps easily, that is when you know it has gone bad!
Our go-to suppliers of filaments are filaments.ca and 3D Printing Canada. The specific brands that we find work well for our needs are BASF and Exonofil. They both offer easy printing and high-reliability plastic filaments for 3D-printing. We stick to ordering filaments with a diameter size of 2.85 mm, mainly due to the size of nozzles we have.
Nozzles
We’ve learned to pay attention to the nozzle size when we go about 3D-printing with our Ultimakers. If we are striving to print something large which does not require a lot of details and precision, we mostly select larger nozzle sizes. Doing so will allow for more filament to come out which, as a result, speeds up the printing time and causes the layers to be thicker. For finer details, like in anatomically accurate models, we used smaller nozzles.
The manufacturing paradox
Unlike other media (e.g., clay), where softer materials are easier to work with, 3D-printing works best with hard materials. The harder the filament, the better the print. Softer filaments are tricky to work with as they clog up the nozzles on desk-top printers, such as the Ultimakers. Unfortunately, most of the human body, which are the objects we are recreating for simulation purposes, is mostly made of soft tissues. Our approach is to use 3D printers to design “molds” (or negatives of the organs and parts we want to recreate), and use silicone solutions to build soft tissue. But more on that in another tip in the future…
Conclusion
As you can see, the Ultimaker S5 3D-Printers have taken us on quite the journey and Google tells us we’ve only scratched the surface in terms of the machines’ full potential. As we continue to work with these wonderful tools at our school, we will be sure to share with the community what we discover next. Until then, feel free to reach out to us if you’re interested in chatting about your experiences with the Ultimaker S5 3D-Printers, we’d love to connect!
Our work, funded by the Canada Research Chairs program, is available for free for non-commercial purposes, guided by CC BY-NC-SA license here: https://github.com/maxSIMhealth/
Submitted by: Mithusa Sivanathan, Julia Micallef & Adam Dubrowski