Solve a Problem

by falconphysics, published

Solve a Problem by falconphysics Jun 26, 2016

Educational Thing


This is a collection of things that represent replacement parts for missing or broken things. These were either created by remixing other models or by creating from measurements of existing parts. I brought these previously published designs together here as an example of a project that could be done with students.

Print Settings

Printer Brand:




Doesn't Matter




Specific settings, of course, depend on the particular part you are making.

How I Designed This

Create a Thing

Bretford iPad Cart Knob
This ended up being a little more complicated than I originally thought. My first attempt looked remarkably like the original part to be replaced, but it failed utterly. I'll explain more below.

Step One is to take good measurements. While you can use a ruler for this I would recommend digital calipers. I use a cheap set. I know this might not be the most precise tool, but for what I and my students need it is more than enough.

The next thing to consider is that 3D printing has different advantages and disadvantages when compared with traditional manufacturing. The original part (pictured below) is hollow. This means the part uses less plastic and will be cheaper to manufacture.

Original Part

I mimicked this part fairly well in my first attempt. However, it didn't even make it back on its first trip out on the iPad cart. The inherent weakness caused by the layers in FDM printing meant it was destined to break. It sheared off even with the handle the first time it hit a wall or door jam.

There is no need to make the replacement a carbon copy of the original. 3D printing has different advantages and disadvantages. It is important to keep these in mind when creating a part. My original take on this part really was nearly identical to the original. It took me a long time in Tinkercad to achieve my near perfect copy.

Failed version with successful final object

The final version of this part was not only much stronger, but took only a couple of minutes to knock out in Tinkercad. It is just a collection of cylinders with a half sphere on top. Print it with two or three perimeters and 20% infill. If the fit isn't quite tight enough just wrap a little masking tape around it.

Remix a Thing

Canon Replacement Covers
Starting from someone else's design and adapting it can be both easier and harder than designing your own part. The hard part comes in seeing where an existing design can be used in a new way to solve a problem. I did just this when I noticed that students aren't as careful as me when swapping lenses on the yearbook cameras.

I first noticed a camera body sitting in the computer lab without a cover to keep dust out. When I asked, the yearbook moderator told me she gave up buying new covers because they just keep getting lost. She also shared with me that they loose the covers for the lenses as well. My immediate thought was to sit down, take some careful measurements and then design and print replacements for her. If these were to get lost I could just print more. However, I was a bit daunted at the thought of engineering a thing to mate perfectly with the camera and lens.

Enter the macro extension tube by martinmunk. This already has the fiddly bits designed to attach to a camera body and to a lens. With very little work this one part could be chopped down and solve both problems. The whole process is very simple in Tinkercad and can be accomplished in only a couple of minutes.

  • Download the stl from Thingiverse
  • Import into Tinkercad
  • Use a "Box - Hole" to remove the unwanted portion
  • Add a cylinder to close off the cover
  • Repeat procedure with the other end of the macro extension tube to create a cover to protect your lens when in your camera bag.

Create a cover for Canon Camera Body


Overview and Background

Students will explore their world either at school, at home, or somewhere else they frequent looking for problems to solve. This could be looking for broken/missing things, ways to make things easier, or things that could improve life. They will create these in Tinkercad for 3D printing. In the process, students will have to think critically about the world around them and will learn about some of the constraints in 3D design and printing.


  • Students will be able to create and print a basic 3D design.
  • Students will be able to evaluate a design, either their own or one they’ve found, and make improvements.

This is a project that could be done by students at many levels.


  • Engineering
  • General Tech Class


  • NGSS Science and Engineering Practices:
    • Asking questions and defining problems
    • Constructing explanations and designing solutions
  • NGSS Core Ideas: Engineering, Technology and Applications of Science
    • ETS1.A: Defining and Delimiting an Engineering Problem
    • ETS1.B: Developing Possible Solutions
    • ETS1.C: Optimizing the Design Solution

Lesson Plan and Activity

  • Introduce students to Tinkercad and give them a brief overview. Something similar to the video below. Have students play and create an interesting thing. I typically have students skip the Tinkercad tutorials and dive right in.
  • Share a couple of the students’ creations with the class and talk a bit about the capabilities and limitations of 3D printing.
    • Would these designs be printable?
    • Would support be required?
    • Should it be printed in multiple parts and then assembled?
  • Introduce the Assignment. Design a part to solve a problem. This can be to fix something broken, redesign an existing thing to make it better, or make a new thing that in some way makes life easier.
  • Send students home to find a problem
  • Break students into groups of 2-3 and have them help each other design solutions.
  • Students use TInkercad to create models for 3D printing.
  • Print, test model, and share with class for input.
  • Students refine or re-design their models to make improvements.
  • Re-print, test and make improvements as needed.


  • One class period to introduce and create a sample thing in Tinkercad
  • One class period to share designs, discuss 3D printing, and introduce the assignment.
  • Try to work in a weekend so students have time to find a problem to solve.
  • One class period for students in groups of 2-3 to measure, plan, and sketch ideas.
  • 1-2 class periods to create models in Tinkercad for printing.
  • One class period for testing and demonstrating to the class.
  • 1-2 class periods to improve on or re-design their objects.

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