I held two machine shop classes for Paideia 2015 and had good groups for both sessions, 11 for the first and 9 for the second. Each student worked through a series of steps to make a finished part that, while not all that useful in itself, was a testament to their newfound shop skills. The part was based on one I made at Mount Hood Community College where I both took and then taught machining classes and it emphasizes layout, drill press use, and hand tapping and threading. Here’s a 3D image from Solidworks.
Here’s the blueprint the students were given to guide their work when making the part.
After a short talk outlining safety considerations and a description of the part we were going to make I walked the students through the process with parts I’d partially finished beforehand showing each step in the process.
They started with a 1/4″ thick piece of aluminum and then worked through the process to layout the holes and arc, center punch the holes, drill and tap the holes, file the arc, and finally cut the corner using a hacksaw. Ultimately the part won’t win any beauty or functionality awards but it’s a good teaching tool and a stepping stone to much cooler projects. Here’s the finished part:
The blue material that’s painted onto the aluminum is called Dykem Blue and it’s the industry standard for marking metals. After it’s painted on and dries you can scribe lines into it for relatively high precision layout without really scratching into the surface of the metal. It stains everything and, after warning the students not to spill it on anything (they didn’t), I spilled it all over the floor leaving a giant blue splatter.
Some students finished early enough to make some threaded rods from short pieces of aluminum so they could thread them into the threaded holes they made in their part.
All in all everyone was very safe with the tools and the parts came out quite good. The drawing doesn’t call out any tolerances so no one was held to pass/fail grading (as would be the case in a machine shop) but many would have passed just fine with reasonable tolerances.
I’m looking forward to getting more classes going during the term and to Paideia next year too.