Building off of the Prototyping with Lego thread, the next step in the design sequence is creating a 3d-printable model. All models in this thread were designed using TinkerCad and printed on a Bambu printer using PLA as the material.
Prototyping with Lego allows students to better understand the geometry they want to design before they get bogged down in learning the design software. It allows them to dive into the project and start being creative immediately.
Then, once the initial 3D-printed model has printed successfully, students can further explore adding hinges, joints, and other methods of articulated movement to their models.
The crane below was printed first as a static bird, with no hinged wings. Later, the hinges were added, allowing the bird to be posed. By photographing the model in a sequence of poses, students can use the images as frames in a short movie that demonstrates the model’s motion.
Through the 3D printing process, we were focused on making our hippo have an adjustable jaw that opens and closes. We first prototyped our hippo with legos with a movable jaw to see how we would design it on Tinkercad. Once we were able to visualize how it should look and move, we used Tinkercad to prototype a 3D model. Tinkercad was initially challenging to use due to its limitations with small adjustments. We decided to design a door-hinge like jaw to connect the top jaw to the bottom jaw. This included 5 barrels (3 on the top and 2 on the bottom) and a pin to connect them. We wanted the hippo’s jaw to be able to shut and open, giving it a “hungry hippo” look. We found difficulty in the barrels fitting within each other, and the pin fitting in them. After numerous prints, about 6 prototypes, and some DIY work afterwards, we found the exact dimensions that worked. After each failed attempt, we noticed a few little details we could fix, but more would come after, creating some frustration. We are now hoping to have our final prototype soon, as the previous one had a printing malfunction that prevented the pin from entering one of the barrels, hindering us from creating the hinge motion.
Building on the Lego prototyping phase, I moved to TinkerCad to design a 3D-printable elephant and printed it on a Bambu printer using PLA. I started with basic shapes to build the legs, body, tail, head, and eyes. For the more complex parts, I layered multiple circles to give the trunk a textured look and used one circle to cut a curved shape out of another to create the tusks.
To make the trunk removable and poseable, I designed a connection that allowed it to click into the head. I cut a hole in the elephant’s head and added hollow lines to the base of the trunk so it could fit into the opening. It took a few tries to get the fit right, so I printed several different trunk sizes and made the hole in the head deeper until everything matched and clicked together perfectly. One thing I learned is to be very careful when removing the 3D print supports. I accidentally broke the tail on one of my models because I pulled too hard on the support material.
