Friday, May 26, 2017

3D Printed Gears Using Dual Extrusion

For our school maker project (in science class), we wanted to create something that kids everywhere would be interested in using, and we also brainstormed different ways to spread our creations beyond the school to reach a wider audience.  We wanted to use our knowledge of 3D printing.  As we saw the rise of fidget products all over our school and all over the country, we realized that we had found our project: we decided to 3D print some fidget spinners that we designed ourselves out of recyclable filament.  There were some technical challenges that we experienced: for instance, the design we created ended up with some overhangs, which you can see in the image above.  To deal with this, we decided to use dissolvable support material to hold them up. We also had to make a decision about what printer to use of the ones available to us at school.  We chose to use a Replicator 1st Gen because of its dual extrusion capabilities, and this served us pretty well.

At first we were just making very colorful objects with two different colors of filament. We made this two color frog, along with some other things. After making a few multi-color prints, we quickly realized that this printer wasn't made just for printing with different colors. There must be some other reason that they made a dual extrusion printer. After doing some research, we found out about dissolvable filament. With dissolvable filament we would be able to make very complicated prints and dissolve the support material in limonene. One of the biggest problems with 3D printing is that you can't get support material out of very small places. With dissolvable filament, it was also possible to make moving parts in one print. Our first test was to make this gear thingy. We then decided we wanted to make more, and designed a different two geared fidget. However, we had a problem, the sides were not fully connected and the model often broke. We redesigned it, and it look something like this:

2.0 coming out of a tub of water after getting soaked in Lemonine

We used TinkerCAD because of its very straightforward design software that all of our group members knew how to use and the fact that we could use geometric shapes very easily along with the community shape generators.

To get started with our project, we started out with a simple dual geared fidget because we had no experience making this type of project before. Starting simple was helpful, and we later were able to get more complicated and make things like triple gears and quad gears.

One of our greatest challenges was when one part of the 3D printer we were using broke. We were able to re-3D print this part but it was a bit of a hold up. We also had to come up with a way to fix the windows for our 3D printer because our print’s kept peeling and we needed to stop drafts from reaching the heated build plate.

Elan fixing The Replicator
Throughout this process we learned not to rely on machines because machine failure is common. We also learned that even if you are using a very baseline software, you can still make amazing creations with it, it just may require more work.

If we wanted to continue this project, we could create more gear designs using ball bearings. This would be hard though because we might have to not print the gears as one piece so we could insert them, or we would have to put them in mid print.

Our advice for other people who do this project is to start early and use a web based software (like so that they will be able to access and change their project from different places.

An estimated cost of materials in this project (not including the 3D printer) is about $40 because of the fact that the slicer and the design program (Tinkercad) were both free, so the only costs we had to cover were filament (ABS and HIPS) and electricity. This $40 could cover many, many gears, because they are almost hollow and therefore very efficient with the material.

Rolls of ABS and HIPS

To learn more about dissolvable filament check out this on MakerBot’s website.

One day while we were waiting for a set of gears to print we chose to make a website at Through our project we had to fix the Replicator about six times and replace some parts. By the end we had created four production lines. And already finished two of them (dual geared basic and dual geared +). We thought that with four different products to choose from we had finally done what we had meant to the whole time, we had finished with our fidget production.