Jesse Kirdahy

Tinkercad: Students’ Urban Gardening Designs

2023-02-01T00:00:00+00:00

One of my favorite lessons I’ve run with middle schoolers is the urban gardening design challenge that a science teacher colleague and I created together. I’ll do a more complete write up of the lesson itself, but I want to feature some student work in this post.

The Challenge

We tasked students with using Tinkercad to create original functional designs that solve some problem with urban gardening, and which can realistically be printed and used in their own home garden either as a completed object, or as a basic but still functional proof of concept that could be scaled up to industrial urban farming. I provided students with a Tinekrcad project that contained models of common gardening objects, demonstrations of design considerations for 3D printing, and my example of a completed project—a fastener that fits over wooden dowels and uses modular bits to hold small diameter irrigation tubes. Here were the constraints for the project:

The design must be functional, not just aesthetic
The design should justify the use of 3D printing (i.e., it should not simply be an existing common object that can already be purchased, like a pot or spade)
A design of a common object is allowed if the student modified it in some significant functional way (i.e., design a self watering pot or a spade that uses an original modular handle system)
Students could use geometry I provided as examples as a starting point but must able to explain and justify why they chose it and how they modified it
Maximum dimensions of 10 cm along any edge, or maximum total volume of 1000 cubic cm (this was mostly to make sure I could print all the designs, so I was flexible with this constraint)
Extra points for modular or stacking designs

Student Work

Here are some of my favorite student designs, the ones that I felt most understood the intent of the project and designed something ambitious. Many of them are modular or stackable pots, or designs that modify an existing pot to make it stackable. The static images don’t do these designs justice, so take a look at them on my Github, where you can rotate them and see how they stack or connect.

Fusion 360: Designing a Replacement Trigger for a DeWalt Clamp

2023-01-31T00:00:00+00:00

A colleague who teaches science came to me with a DeWalt trigger clamp that had lost its trigger, and he asked me if I could print a replacement since trying to order one through official channels could take months or a full school year. Fulfilling this request would be a small coup for me as I was trying to show staff the direct benefits to them of having 3D printing in house.

A quick look on Tinkercad and Printables showed no existing designs, so I got started creating my own in Fusion 360. Since I’m still learning CAD, any opportunity to practice designing different objects is welcome. I took some reference images and started with a sketch, as I’m working on understanding constraints better. The rest of the design was pretty quick, and I was able to print a prototype in PLA on one of our Prusas that afternoon. Testing showed it fit and performed its action well and only needed a little tweaking, so I thickened the geometry that performs the action a little, and then filleted to my heart’s content and printed a final version on PETG on my Voron. In the final print, I changed the orientation to make the filleted parts that the user’s hand touches print smoother. (The moire pattern on the print was because bolts on a part connecting a Z belt to the gantry were coming loose.)

Check out the design timelapse below or download the design files from Printables.

Sculptfab: 3D Sculpting for 5th Graders

2023-01-30T00:00:00+00:00

3D sculpting tools like the free Sculptfab or SculptGL make it quick and easy for students to see desirable results in their designs. Unlike other simple 3D design tools like Tinkercad, which uses parametric geometric primitives, sculpting tools offer intuitive controls that respond to direct clicks or finger taps, showing results immediately. It’s for this reason that I tend to start students with Sculptfab when they’re beginning to learn 3D design.

Sculpting Calaveras for Dia de los Muertos

One of my colleagues, a fifth grade teacher, mentioned she was doing a couple of Dia de los Muertos lessons to tie into a novel the class was reading, and I jumped on this immediately since I was trying to build students’ interest in 3D printing. I suggested students could design and print calaveras—the colorfully decorated skulls that Central American cultures make out of sugar for Dia de los Muertos. My colleague put together a slideshow for students about the cultural significance of the day and the skulls, and I got busy figuring out how we would do the design and printing.

I’ve used Sculptfab and SculptGL in the past, and I decided to go with Sculptfab for this lesson since the file management is slightly easier in it, and students who had gotten accustomed to using Chromebooks with all their work automatically saved on Google Drive would need to manually download and then send me their files. (I cannot believe how hard it is to help children understand filesystems and file sharing.) Additionally, Sculptfab’s UI is just a little bit cleaner than SculptGL, and the simpler the better when introducing new tech skills like this to students.

With any lesson where I’m trying or creating a new product for the first time, I find it’s essential to go through the entire process myself. Packaged curriculum that has already been tested often needs this, and bespoke lessons even more so. By “debugging” a lesson, you inevitably discover things in practice that you can’t always anticipate when just thinking through a lesson:

The skull model required modification to flatten a surface in order to be printable, and students would not be able to sculpt over this flattened surface
The original poly count of the model made it difficult to work with, necessitating reducing it before distributing to students
The skull model broke in certain areas while sculpting, and Sculptfab’s tools couldn’t easily fix that once it happened
Certain keyboard shortcuts produce unexpected behavior in Sculptfab (looking at you Command + Z)
The camera would be tricky for inexperienced students, and the camera reset menu item looked similar to the project reset menu item

Once I felt confident that students would be able to go home with a printed calavera, we started the first lesson. I’ve found that the best way to introduce a new tool is to go over only its most essential aspects—usually UI basics and file management—and then give students the time to experiment on their own. This means students who are ready to go don’t need to wait through endless directions, and students who aren’t sure can stay and ask questions. By keeping the time focused on me to a minimum, it also builds trust with students that if I am trying to get their attention during the lesson, it’s probably worth tuning in to hear what it’s about.

Since this was one of the first 3D design and printing lessons I had done with this particular students, I thought it was important to specify that a typical project could have more complex geometry, but for these, it was imoprtant not to have large protrusions from the skull. Some students insisted they wanted to try it, and I consider it a learning experience about what will and won’t print from a design, so I agreed to let them make what they wanted with the understanding it might not print correctly.

Students did well with Sculptfab, and in the end, everyone had a calavera printed. It’s really important that students have a good first impression of projects like these because if they walk away frustrated, they may never attempt it again. If they walk away with a printed object they’re mostly happy with, but feel like they have things they’d want to improve, that’s exactly how I want them to feel. There’s plenty more to learn, and they are capable of learning it and getting the results they want.

With the calaveras printed, students’ next step was to work with our art teacher to create a display for them, and to write a two sentence horror story to accompany them. I love how they turned out. The hallway display was beautiful, and it inspired other students who saw them to ask about how they could do 3D printing at school. Perfect!

Next Steps for Students After Sculpting?

While I ran this lesson with inexperienced fifth graders, I’ve found fourth grade to be about the right age to introduce students to more demanding and more capable design tools like Tinkercad if they have already had some experience with 3D sculpting. Any earlier can be tricky in part because of physical challenges—it’s harder for little hands to manipulate a mouse and keyboard together to orbit and rotate in 3D space—but also because they are intellectually developmentally at the right stage to learn the ins and outs of more complex softare and concepts of designing for additive manufacturing.