3D Printing STEM Projects and Information
3D printing has become very affordable and there is a lot of mathematics that can be learned when designing projects. The plastic of choice for schools is PLA which is actually a corn starch but also a very good building material and lasts for a few years. The choice of printers is large now and in the beginners or entry range are some quality well priced machines. Do your homework here, ask around.
My printer is an Aquila X2 made by Voxel Lab and supplied by MakerShop in Auckland. I chose this one because of the $400 price, the reports were excellent and I could buy it here in NZ. It was delivered a few days after ordering and I was so impressed after printing a few jobs I bought another which remains unpacked under the bench. I bought a variety of PLA colours and some ABS to experiment with as well. No other spare parts needed yet. It comes with a printhead nozzle cleaner and assembly tools.
Assembling the printer was quite straightforward but I also looked on the internet for Assembling the Aquila X2. The link takes you to a Utube presentation on building and levelling the printer. An invaluable help. There are several versions.
HINT – If you are in a school build this printer with a couple of tech-handy students. You are going to need a techie just to keep an eye on and help out with “levelling”, “loading”, unloading”, “plastic jams”, “general care” and “a go-to person”. Keep it covered when not in use and use it on a solid bench to eliminate vibration and bumps. Train a 3D Printer Student.
Levelling the print bed is important. The heated bed the print is made on is about 0.2mm below the print head. The print head moves in a level plane and the bed is adjusted using twist screws on the four corners. A piece of A4 paper is used to just grab the print head and so create a constant gap across the bed. See the utube vide. I spent 30 minutes convincing myself the level was correct and have only readjusted it once more in 6 months. This printer has an offset adjustment as well to raise and lower the print head 0.1mm at a time.
Using the 3D Printer
Step Zero – Have a small project in Mind. Always have a purpose! This approach has an end point and you will naturally refine and develop ideas.
Step One is Designing whatever you might want to make. I like math puzzle models so my first projects were to design the Soma Cube, Maltese Cross, Pentominoes and a Packing Problem. This was done on CAD software.
Tinker CAD is free and an excellent first choice introduction to 3D design. It is intuitive to use and learn.
Here is a screenshot of the home screen and one of the work space showing my Maltese Cross design. Tinker CAD is based on AUTODESK which is one of the standards of professional 3D design. Good future proofing for careers!
Once designed the file is exported to your computer in .STL format. Here is an example. This is the icon for my Maltese Cross in the picture above.
Step Two is the SLICING SOFTWARE – This comes with the printer and is the software that looks at the .STL file and creates a series of layers that build up the 3d print. The print head prints each layer, one by one, to build up the final model. The slicing software is CURA and is free. No need to download as it all comes on the little SIMM that comes with the printer.
This is the 35th slice out of 50 in total and shows the internal structure.
The fill and fill pattern can be changed, a raft can be added as shown. I use a raft to build the model on so that I have flat edges on the bottom layer. One of the many things I learned. I had to hand file my early models! The adjustments that can be made to the print file are many and I will leave that to you to discover.
Step Three - TRANSFERING THE FILE TO THE PRINTER – This had me puzzled. It does have a USB port which I have never used. My Mac has a Micro-SD port and so does the printer. Job done. Insert the Micro-SD and it just appears on the desktop of the computer like a Data-stick and drag and drop the file to the Micro-SD card. Eject from the Mac and inset into the printer. Select PRINT, select the file and everything starts to happen. The plate heats up, the print head heats up and then when it is at temperature the printer moves and prints.
LOADING and CHANGING PLA – The Aquila has a control screen and Automatic Load and Unload can be selected. This is really easy to use. I did break the PLA filament a couple of times by leaving it too long in the printer or letting it dry out or something. That required figuring out how to extract broken pieces. Not hard and it reloaded easily. Hint is when finished a print “Auto Unload”. It is easy enough to load it again.
MAINTENANCE - I asked Mike at MakerShop if there is any maintenance and he replied -
I'm glad to hear that you are having such a great success with your printer. We'll be getting more, but for the moment we're out of stock. Better get onto that if you're promoting them for us.
There's no specific maintenance that I would recommend. Just generally keeping them clean. Removing dust. Avoid storing it in a damp place.
Keep an eye on the filament drive roller. If the teeth become clogged then clean them out with a pin or a blade.
The filament tube and the nozzle are the parts that may need to be replaced eventually. We usually have these in stock.
Perhaps more important is keeping your filament dry. Any opened filament rolls are best be stored in a sealed container with some desiccant and you should reactivate the desiccant periodically by baking out any moisture. You'll get better print quality and fewer print failures with dry filament.
Regularly wiping down the print bed with alcohol (ethanol, methylated spirits or IPA) will help with adhesion. It removes the oils that comes from touching it with your hands.
I would add to keep an eye on the drive belts which must stretch after a while. Just tighten a tinch every so often. Check the bolts are all tight on the frame. The fans and motors will eventually wear out but after thousands of hours. Mike has spares.
Starter Projects – The design is the learning with STEM.
This is also from Mike at MakerSHOP.
One of the messages I would like educators to understand is that learning to use a 3D printer is not the goal here. The goal should always be to get students excited about design and problem solving. The 3D printer enables students to turn their designs into something tangible and functional and helps to motivate students to learn new skills in design.
Tinker cad is a great starting platform. From there you might want to look at Fusion 360 or Onshape. Both are free for non-commercial use and have ready-made course materials for educators.
#1 Packing Problem Price $30 posted anywhere in NZ.
This packing problem is about fitting six 2x4cm blocks into a 3x3x3 cube. Easy shapes and a great first project.
The white box is actually hollow and has a lid. Inside are six 2x4cm cubes.
It is an easy project to design with some interesting measurement tolerances that have to be estimated so everything fits. It is also an interesting puzzle to solve. A bit of fun.
Available in a range of colours and if you want to print your own email firstname.lastname@example.org and ask for the .stl files.
#2 The Pentominoe Blocks in a 3x4x5cm container.
The pentomine shapes are fascinating and an essential way to begin any maths Year 9 course. See my Chapter 3! As solid 1cm thick shapes and there are 12 of them there are 60 cubes in total. Sixty is a fantastic number because it has so many factors. The box here is 3x4x5 but it could easily have been 6x10x1.
More starter projects coming.