3D Printing: A hand guide for ecologists

3D printing may seem like a hyper-modern, futuristic tool from Star Trek or Doctor Who. But the first comprehensive outline for the technique was described in 1974 (by David E. Jones), and was in practice at some manufacturing companies all throughout the 80’s. Most popularly, it’s a great way to design prototypes of complex machine parts that have unusual shapes. But now it’s a common technique for most inventors, as well as hobbyists who have small, affordable 3D printers at home. And in many cases, it’s available for a small, small cost at your local library with the help of tech experts.

The Printing Process

The printer’s function is important for all aspects of the project, from design, to printer settings, to finish. The project doesn’t just magically appear, but (most commonly) is created using “fused deposition modeling” (FDM). Essentially, this means that the printer melts the material, and squirts it out on a the printer bed. But it doesn’t just squirt out a whole product. It lays out a thin layer of plastic on the printer bed’s plane. After that layer is done, the printer prints another layer on top of it, repeating the process until the project has taken shape.

There are lots of parts to a printer, but I’ll lay out a few that will make further explanations easier to understand.

http://blog.supermediastore.com/article/nitty-gritty-3d-printing
  • Print bed: the flat board that the material will land on. Think of as you bottom, or even x-axis and z-axis plane.
  • Hot end: the nozzle that the printing material will squirt out of once melted
  • Extruder: the chamber where the material is melted for printing
  • Filament: the plastic tube string that is the material for printing

Designing a Project

Designing your project is the most creative part of the process, and there are lots of platforms (free and not) to design on. I like to use TinkerCad, since it’s open source, online, and relatively user friendly. It’s great for hobbyists, or non professional designers, and it’s outputs are compatible with most printers we’ll run into. For a quick and comprehensive tutorial, check out this Tinkercad video.

Since the printing process is essentially layering plastic on itself, you can see why you can’t just print any sort of shape imaginable. The printing process relies on gravity, and each layer must print on something else. Sturdy, solid objects are generally easier to print than thin, flimsy ones. Sometimes this can be as easy as laying the object in a different way on your bed. For example, if I wanted to print something shaped like a pencil, it would be easier to lay the pencil on its side in the design than on it’s eraser. But that doesn’t mean we can’t get creative with our designs! I’ll explain how to get around the little problem of gravity later in the print prep section.

Here are some tips to keep in mind while designing that I came across.

  • Use the copy+paste option whenever there’s a repeating element. It saves so much time, and keeps things consistent.
  • When you use copy+paste, try and use the arrows on your computer to re-position the new element, especially if you want it to remain even to the original in at least 1 of the 3 planes (x, y, or z).
  • Group elements as you go, especially for repeated elements that might need a bit of adjusting as you go.
  • Keep gravity in mind! Floating objects will just fall to the ground in a clump when you actually try to print them.
  • Make sure different elements are securely connected. If elements are only barely touching, they’ll probably fall apart in real life.
  • You can only use one color when printing, but you can always paint your object afterwards if you like/have the time.
  • Think about material availability if you’re printing lots of copies. There won’t be endless filament, especially if you need them all to be the same color.
  • Export your project as .obj, and save onto a flash drive if you are going to print at the library.

Print Prep

Once you’ve designed your project in TinkerCad, you’ll take that file to the printer. For our group, we like to use the Toronto Public Library’s Fort York Branch. They have some great techs there that help with design, prep, and machine work, and the price is one 10 cents per gram (that is a steal). They have several brands of printers, and certain printers require certain software programs for you to prep your design in. All you need is a library card!

Prepping is the step when we make decisions about settings for the printing project. This includes things like layer size, supports, rafts, and other things specific to the printer in question. After you’ve personalized each setting, you’ll save that new file to an SD card, and insert that SD card into the machine itself. (At the library, the techs will help you with this part).

Basic settings will work for most projects, but as you get more advanced, it’s nice to have some options to optimize your printing. When changing settings, always take into account the print time (it can get very long if you’re not careful) and filament use (you don’t want to be wasting filament on extras you don’t really need).

When part of your design “overhangs” the previous layer, you can employs a printing strategy called supports. These are essentially buttresses that the program will insert for you once you are prepping your final print. These supports print underneath the project itself, and are removable (but be gentle when you snap them off!).

Rafts are another type of support, that are helpful when you have a project that needs a strong base. It prints a thin sheet of plastic that you’re design will be printed on. This makes your project a lot longer to print, but is necessary when the bottom of a project isn’t simple.

Layer size will determine the thickness of each printed layer. The thicker the layer, the coarser the design will be, so if you have a very detailed design, I would recommend making it a smaller layer size. However, smaller sizes take a lot longer to print, so if your design is a simple shape, keep if coarse.

3D Printing is Versatility

It’s not only printing objects themselves that 3D printing can be useful for. A common practice is printing molds of objects that you’d like to make copies of. This is a great option if you think you might need to make more in the field (when you don’t have access to a printer). Resin, plaster, rubber, and cement are all common mediums for mold making, and can be bought at most hardware stores.

3D printed objects are also great replacements for machine parts that have gone missing, or need customization. Need a new handle for your net? A back for your GPS unit? A special box for strangely shaped equipment? You can absolutely 3D print that! And on top of that, superglue works great with 3D printed materials, so you can print parts and combine later.

I got into 3D printing for creating mimics of cactus fruits, which are a strange shape that I can’t find in any shop (scientific or otherwise). So for experiments when you need a control for shapes (this is great for facilitation experiments), 3D printing your objects is an excellent option.

It may seem intimidating, but 3D printing is an accessible tool that can be learned in an afternoon. And you might even find yourself making some projects just for fun!