Building an airplane – July 4, 2017

Craig drills holes for rivets in one of the wing ribs.

Craig widens the hole in a steel fitting while Chip checks the accuracy of his bend in an aluminum tube.

While many businesses were closed for Independence Day, Chip, Craig, and I put in a very productive and satisfying day of work on the Zigolo, starting at 7:30 AM and ending at 5:30 PM. We essentially finished several subassemblies, including the vertical and horizontal stabilizers, the rudder, and the ailerons, and we made significant progress on others. It’s exciting to see actual recognizable airplane parts emerging from the chaotic heap of tubes, sheet metal, and nuts and bolts we started out with – and it’s only the second day of work!

Prior to starting work on this project just yesterday, I had a very wrong impression about what assembling an airplane kit was like. I thought it would be like an IKEA product, where all the parts were manufactured in final form and ready for assembly; all you had to do is find them in the right order, fit them all together and tighten down some screws. The reality is almost every single structural part needs to have holes drilled or widened before fastening them together with rivets, and a number of tubular parts need to be bent by hand to a precise shape first.

In short, there quite lot of skilled labor involved, and we are extremely fortunate to have Chip here to show us how it’s done. I have no doubt that we wouldn’t have gotten even 10% as far during the first two days if we had had to muddle our way through things on our own.

At first I didn’t understand why the parts couldn’t have been fabricated from the get-go with the right-sized holes. It finally dawned on me that the pre-drilled holes were there mainly to allow the parts to be properly aligned and then provisionally fastened together with clecos, after which the full-size holes could be accurately drilled and riveted in place without the possibility of slight misalignments in the pre-drilled holes causing big problems.

Anyway, at times the dominant sounds in the work area are of someone drilling, of someone else (or maybe the same person) using the pneumatic riveter, the compressor operating to keep the riveter supplied with 90psi air, all punctuated by the occasional use of the bench grinder and/or a file to remove burrs that could interfere with assembly or with the operation of moving parts. In the course of the day, the floor quickly accumulates a layer of aluminum drillings and filings and mandrels (the breakaway wire shafts of blind rivets).

Speaking of rivets, we discovered last night that riveters sometimes jam. When they do, they’re impossible to unjam unless the right tools are handy (they weren’t!). Also, taking the only available riveter out of service potentially means that all work comes to a standstill. So one of my last tasks yesterday after leaving the site was to buy not one, but two, new riveters. The first was for the eventuality that we might not get the original riveter working again (we didn’t). The second was intended as a backup for the first – we didn’t want another unscheduled end to our work day.

(Another adventure ensued when I set out to buy some tools and materials at Ace Hardware and decided to also try to finally check “pinking shears” off of my shopping list. Pinking shears are needed for cutting the fabric that will eventually be attached to the wings and other surfaces, and they are typically found in sewing and craft stores, not hardware stores. The first crafts store I drove to turned out to be closed for July 4th. I called the next one and confirmed both that they were open and that they had pinking shears, only to arrive and learn that, whoops, never mind, no pinking shears. The third store had them, but by then I had added another full 30 driving miles to what should have been a short run to the hardware store. I also had to explain to at least two store employees why I urgently needed to buy pinking shears on Independence Day [“I swear, we’re building an airplane!”])

Post script: At the start of today, Chip had conservatively estimated that we might get 65% of the plane built before his first visit ended on Saturday. By the end of the day, he acknowledged having raised his estimate to something higher, though I don’t know by how much. The important thing is that we’re finding our rhythm and figuring out how to work in parallel, and the project is moving along at a seemingly good pace despite some early delays with missing tools and other materials as well as due to my initial helplessness with figuring out things to do (and how to do them) from looking at the assembly manual alone.

Post script #2: A grateful shoutout once again to Bob Paulos and Gary Anderson for providing the space for this project at the Physical Sciences Lab in Stoughton. Especially now that the work has ramped up to full production mode, I am reminded time and time again how perfectly suited this space has turned out to be for what we’re doing. Now if only there were a small grass airstrip at PSL!

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