Several classes ago, I introduced a Graham cracker protection unit to my middle school STEAM class. This initial activity was a Graham cracker drop – i.e., just like an egg drop, but 1000% less messy. After the first Graham cracker drop we had a class discussion about why some devices were more effective than others and how we could use that information to create better devices for a second round. Unthinkingly, I asked the groups to make a drawing of their planned devices before they could get materials.
Wow, were those drawings weak! I didn’t photograph any of them for before-and-after comparisons, but the initial drawings contained almost no usable information. At this point, I realized we needed to take a detour and do a study of technical drawing before proceeding with the Graham cracker project.
First, I had students create K’nex vehicles from a professionally prepared technical drawing.
As expected, that went smoothly. Some students had a bit of trouble with a few details, but there were no major challenges. Next, I gave students technical drawings I created and drew. The students used these drawings to build the object shown.
Once again, all of the groups were able to successfully build the object with only minor difficulty. At this point we had a class discussion about what a technical drawing is and what distinguishes a “good” technical drawing from a “bad” technical drawing. The main points we settled on were that a technical drawing had to convey information clearly enough so that another person could re-create the object. I made a particular point to emphasize that a technical drawing does not have to be beautiful or emotionally expressive. I also showed the students how they could trace the K’nex and/or simplify the shapes and use labels for clarity if they did not feel confident in their freehand drawing skills.
After building two objects using technical drawings, students were now ready to design their own objects and create technical drawings of them.
As you can see, these drawings came out well. Most importantly, they contain enough information for another person to use the drawing to re-create the object. I am thrilled by the development students showed in their understanding of technical drawings.
I wanted to make sure students had some practice with technical drawings using the Graham cracker protection materials (as opposed to K’nex) before going back to the original assignment. With that in mind, I created a technical drawing of a Graham cracker protection device made from construction paper and tape and had the students re-create it.
All of the student groups were able to use these drawings to make a fairly good reproduction of the device I designed and most of the groups created a very good reproduction.
Finally, the teams were ready to design, build, and test their own Graham cracker protection devices. They came out great! My photos did not come out nearly as well as the technical drawing or the devices did, so I will end this blog with this photo – if you look closely, you can see the technical drawing the students created on the left.
I’d consider this project a success. The students improved their technical drawing skills dramatically. They learned about the engineering process and about the physics of forces. Perhaps most importantly, they exercised their executive functioning skills by having to plan their designs ahead of time. Since many individuals in this group have relatively weak planning and self-control skills that was particularly important to me.