Who are you? Christie Silkotch. I am a library assistant here at EHS and have helped set up the makerspace and coordinate our 3D printer purchase.
What did you make? Replacement pieces for my car.
Why did you make it? I drive a station wagon that has a removable cover to conceal the contents of the hatch (trunk). There are two pieces with a screw that create a clip to hold the cover in an extended position. The pieces from one side of the cover fell off somewhere in my travels and I have been going without a cover ever since. The perfectly practical design challenge!
How did you make it? I modeled both pieces with free, simple software. For the blue piece I used SketchUp and for the pink piece I used TinkerCAD. I used a ruler and digital calipers to grab exact measurements and then I built each piece out of shapes. Breaking things down and thinking about the best way to create a piece is the fun part about modeling for me.
What did you learn while making it that might be useful to others? TinkerCAD is a great way to learn and get comfortable in a 3D environment but once you want to make unique custom shapes it really makes sense to step up to something more powerful. I had fun trying to push it and manipulate it to do what I wanted though. You can see on the pink piece that there was a shape that did not fully merge together (I created a shape with a square, rectangle, and a triangle). Luckily this join is only superficial and does not affect the integrity.
I also tried to use a flexible PLA to model the smaller piece, since the original one was rubber, but had trouble getting a quality print. I ended up just using the test piece I printed with regular PLA. There are a lot of forum posts out there about temperature, speed, and other settings to manipulate to get the best print with this material…check them out and give it a shot! It’s maybe not as versatile as I had hoped but it will be worth experimenting with.
Our Ultimaker does not use a support material; this means there is only one type of plastic extruded and the machine does not have another material to build up a scaffolding to support it. As a result, you have to be very conscious of what orientation you choose to print your object in. Are there overhangs? Will it try to start a layer in space? Think carefully about how the machine assembles the objects alongside what you are printing. For the pink part I used an option within Cura, the printing software, to add a temporary support material out of the same plastic while it is building. It’s not cosmetically perfect but this allowed me to make a piece with overhangs into space–without it collapsing on itself or making a rat’s nest!