The wheels were in motion now and all three sections of my seventh grade math classes were hard at work on their respective components of the benchwork. In addition to the attention that they gave to their own parts of the project they were of course very interested in what the other sections were doing. Since everything took place in the same room it was natural for them to examine each other’s works in progress and think about how the various parts would come together. A very stimulating balance of mild competition and collaborating towards a common goal emerged.

The legs team completed their work first when they used small hammers to tap the t-nuts into the holes they’d drilled and turned in the carriage bolt adjustable feet. Some students spent quite a bit of time just playing with the full range of adjustment in the carriage bolts, marveling at the clever design of the fitting and perhaps only now fully understanding why they’d drilled those holes.

There was really only one other component needed before we could start assembling the benchwork: the gusset plates. I was gambling with the idea of masonite rather than plywood gussets, but I wanted to use a material that students could cut easily with a hand saw. When I bought materials at Home Depot I’d had them slice a sheet of 1/8” masonite into 6” and 12” wide strips, intending to use them for fascia and backdrop panels, so strips of masonite were close at hand and I ended up designing the gussets to use these strips. Equilateral triangles cut from the 12” wide material for the leg-to-L-girder connection, and two different shaped panels for leg cross braces, the lower of which gets clipped to a chunk of 2x2 screwed into the wood frame under the blackboard chalk rail. This would be (almost) the only place the benchwork would be anchored to the room. I was depending on being able to “jack in” enough tension in the structure using the carriage bolt feet to provide stability, and so far that seems to have worked effectively.

Cutting the gussets turned out to be more interesting than I’d anticipated. Here’s the sketch I made for fabricating the lower cross brace gussets with wall clip extensions:

For some reason even my most geometrically adept students were scratching their heads over how to lay out these parts using the sketch, at least until they’d worked it out on the first one.

It was wonderful watching students develop their skill using a hand saw on sheet material. Several of them really made remarkable progress in their ability to hold to a line, and even more importantly they acquired a genuine sense of what they were capable of learning to do. Masonite proved to be an exceedingly forgiving material for our gusset application. Easily cut by hand, and using stud screws to assemble the gussets to the legs and L-girders allowed students to make the fastenings without pilot holes (once they got the knack for putting some body weight behind the screwdriver when starting a screw into the masonite).

The gussets made it easy to assemble the benchwork components quickly and each team got to participate in the final assembly. As with many aspects of the components, I suspect that the final arrangement of the benchwork sections wasn’t completely clear to at least some of the students until they could see the finished product standing there in front of them.

Having this hand crafted artifact in the room made the more mundane math lessons vastly more palatable. 

Jeff Allen