My Wooden Airplane
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Crankshaft Shipping Box

Several months ago, I picked a different crankshaft and brought it down to a recommended machine shop to have it reground. They did a fantastic job, so I decided to press my luck. Against William Wynne's recommendations, I had them drill and tap the crank for the Safety Shaft. I should have known better. They managed to thread the crank alright. The Safety Shaft fit perfectly. However, when I took it home and tried attaching the Prop Hub, it wouldn't fit on straight. It turns out they didn't drill the hole straight! (In his Conversion Manual, William says NOT to take it to an automotive machine shop, but to a regular machine shop, "preferably run by a silver-haired gentleman".) I took it back to them, and they said they could fix it. I suspect they were going to put it into their "crank straightening machine", which is probably nothing more than a hydraulic press. I wasn't comfortable with them bending the aluminum Safety Shaft, and I certainly didn't want a bent crankshaft, so now I'm on to Round 3.

I had recently learned that Pramod Kotwal, proprietor of Nitron, Inc. (and also of a sister company, AeroVair), had ready-to-ship (cleaned, magnafluxed, ground, polished, drilled, tapped, and ion nitrided) crankshafts available for exchange. This is the company that I would have had to send the previous crankshaft to for nitriding, anyway, even if the Safety Shaft was threaded properly. So, I built a sturdy plywoood box (24" x 8" x 8" external dimensions), grabbed the last "good" crankshaft I had, wrapped it in a plastic bag and then some carpet, and stuffed it into the box. It cost a little under $75 to ship the 39 pound box from Las
Vegas, NV to Lowell, MA (in addition to the $570 exchange price), but at least I will have
the peace of mind that the entire crankshaft will be correct and properly prepared.

Total Time: 4.0 hrs.