EAA Chapter Develops Educational Sheet Metal Project

EAA Chapter Develops Educational Sheet Metal Project

By Bob MacDonald, EAA 10770 and Chapter 84 Secretary

At one of our EAA Chapter 84 board meetings in early 2017, chaired by then President Richard Morrisson, EAA 561613, we discussed possible chapter outreach activities for our booth at the upcoming Paine Field Aviation Day and the Arlington Fly-In (AFI). Jim McGauhey, EAA 561778, then the Young Eagles chairman and the spark behind Chapter 84’s participation in EAA’s Give Flight project, suggested that we give visitors a chance to pull a rivet to see how airplanes are made. 

I suggested that we could do more and volunteered to come up with something.

Before doing the final assembly step of pulling a rivet, builders must dress the edges of sheet aluminum components, drill and de-burr holes, and perhaps do forming using a brake. During this process, they use clecos.

What if we could give our visitors a chance to do all of these steps?

Some sketching produced the Sheet Metal Fabrication Demonstration Device, later dubbed the “widget.” In addition to demonstrating the steps (except for drilling, which might be a safety issue for our target visitor), it is also designed to suggest the shape of an airplane and to have an actual use – it is a pen/pencil holder.

I made up a prototype and showed it to the board, which approved it, then made several kits and an assembly line. We gave it a test run at our May 2017 general meeting where several bugs were worked out.

Plans for the widget.

Barbara Tolbert of AFI arranged for a local aerospace company to donate a 4-by-8 sheet of .032 clad 2024-T3, which proved to be the ideal material for the kits. She and the donor’s representative were delighted to receive completed widgets as thank-you gestures.

We’ve moved about 30 units at each of our last three events and will offer it again at AFI in July. Chapter 84ers who volunteer at the widget table must have made one themselves before working with visitors.

Kit pieces and completed unit.

It’s fascinating to watch young people quickly get the idea at each step. There are four bends and after the first, no further instruction is needed in most cases. Parents almost always thank the 84er for the experience offered their child.

Chapter President Jim McGauhey (right) thanks presenter Bernardo Malfitano and gives him an EAA cap, pen, and penholder.

We also give the completed penholders to visiting presenters at our chapter. Our custom has been to give EAA caps to presenters of the program at our monthly meetings. Then Richard, after swapping jobs with Jim, got some fancy Young Eagles pens that were also suitable. Long story short, we decided to give both to presenters, and, hey, if you’re going to give a pen, why not give a penholder too?

Instructions:

The chapter member should make a widget under the supervision of another member at the start of their shift. This will ensure that all of us are working from the same page.

Use the alclad kits (with the blue film) first.

Here are the work items to be done by the maker. Comments or actions by the assisting member are given in italics.

The parts are wing, strut, and base.

  1. Put on safety glasses.
  2. Remove the drafting tape holding parts together. The protective film and the drafting tape on which the bend lines on the base and strut are to be marked should be left on until Step 6.
  3. Dress the edges of the base with emery paper and a sanding block. De-burr holes with a de-burring tool or drill bit. The wing and base are already done but advise the maker to confirm and touch up if necessary.
  4. Mark the base and strut flange bend lines. The base flange is 3/8-inch wide; the strut flange is 1/2 inch. It takes a little practice to use the flange marking tool. The maker will need help.
  5. Base of the penholder presented to EAA Director of Chapters and Communities Charlie Becker.

    Bend the flanges using a brake. Use a gauge to ensure there is a 90-degree bend.

  6. Remove the blue film and drafting tape on the bend lines. Advise the maker to handle the parts by the edges if possible to avoid fingerprints on the alclad surface. Attach the base to the strut with one cleco inserted from the bottom, then set a rivet from the top, remove the cleco, and set second rivet. Do the same for the strut to the wing except that cleco is inserted from the top. A No. 30 drill bit and motor will be on hand to drill out any rivet mistakes. The ink, if any, can be removed with lacquer thinner (by the chapter member) or by the maker at home with Bon Ami cleaner.
  7. Straighten the completed assembly if necessary. The wing trailing edge must be parallel to the rear edge of the base as viewed from above. Viewed from the rear, the wing and base must be parallel to each other and perpendicular to the strut. The maker may need help with this.

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