The 4 caps of our family's Cricket Cage broke. We taped them for a while and were going to use glue to fix them, but then we had a thought about making them better redesigning them. We used digital calipers to measure the existing tubes for the diameter, depth, and wall thickness.
This could be adapted for any home school project for pets in a one off manufacturing process. Connect this with Measurement & Data Common Core Standards - http://www.corestandards.org/Math/Content/MD/
Overview and Background
This was used in our family to show the basics of 3D modeling and design. It provided good practice with using and reading a digital caliper.
This could be adapted to an item that is really a one off manufactured part and something that is not an "off the shelf product."
This provides a good discussion about Product Design, Materials, and Recycling. This could expand into a week long exploration into Product Design if it is linked to the documentary Objectified - http://www.hustwit.com/category/objectified/ I have no connection to this movie, the producers, or director. It is a good starting point for discussions about the objects all around us.
Lesson Plan and Activity
Have students find a simple part. This means a part that does not have too many internal openings, overhangs, or shifts directions. Items that follow basic squares, rectangles, circles are good. This cap was really a cylinder and easy to measure. This could be done in the classroom or at home. Preferably it is an item that is broken and a 3D printed part would be a good, practical example of home manufacturing.
Have students measure the object with digital calipers. If the object is complex, you could place the object on top of a flatbed scanner and scan the object. Another option is laying the object next to a ruler (mm or in) and take a photo of it. Sketchup allows you to SCALE the model based on a known dimension. Just make sure that the model only contains the object you wish to scale because this feature will scale up everything in the Sketchup model.
Students can build the model in Sketchup. They may need some training in this software. There are many great videos and online tutorials to reference.
Have students learn the process of "measure twice, cut once," which means in the digital world, measure twice to double check dimensions. Also have them practice their skills of observation to verify that the object on the screen looks like the actual product.
Have the students print the file. The "prototype" might not fit perfectly. Make sure that students are prepped for this disappointment. As Mythbuster's Adam Savage always said "failure is always an option." https://www.youtube.com/watch?v=i5sbUi3_w3w In the world of 3D printing, it happens. Things need to be remeasured. Materials and machine variations have different tolerances. This is a good discussion for the group in how to consider tolerance into their digital designs.
- Have the students create a digital slideshow of their parts and present them to the class. They could provide the reasons they chose the part and what challenges they had in the 3D modeling process.
- Sketchup Make
- Digital Calipers
- An object that has a function (caps, boxes, cases)