Wednesday, January 25, 2006

Tonight's topic: precision measurement

It was a far more cerebral night than usual tonight. Our discussion for tonight had to do with precision measurement tools like micrometers and calipers. Micrometers measure down to .0001", but require meticulous practice and attention to detail to make a consistent measurement. Calipers measure down to .001", an order of magnitude less precision, but are easier to use consistently.

Size matters too. Calipers can measure up to 6.000", while a typical set of three micrometers ($39, Harbor Freight) will have three sizes, ranging in measure-width from 1" to 3".

Older style vernier calipers are tricky to read. I bought a dial caliper instead (on sale for about $14 at Harbor Freight) and have found it much easier to use. The FAA remains certain that we shall all be thrown 80 years back in time at any moment so mandates that we demonstrate the ability to read vernier calipers, but it's not likely that I'll ever need to do it. At least I can explain it to Rick now.

The micrometers take a little effort to read, too, but with a little practice it gets a lot easier. For another $20 or so, I could probably have gotten one with a digital electronic readout, but I kind of like the mechanical style. They have a nice feel to them, tactilely exuding an aura of supreme confidence in their accuracy. We won't really be using them much until engine shop, but as tonight's small class perk, we went to the engine shop to measure stuff. We get to do a lot more than the day classes do, and it really makes the time fly by. Of course, the biggest benefit is that the depth of discussion goes far deeper than what you could do in a 30 student class. It's been a long time since I've had such an interesting and thorough educational experience and I'm enjoying every minute of it!

Tonight was my first visit to the engine shop, and it has me re-considering whether I want to try to take only airframe classes in a rush to get at least half of the A&P done, which had been my previous plan. Now I'm wondering if I should just take the classes that would be of interest to me in either category, and save the stuff that's really not applicable to what I want to do with the certificate until later. The engines sure looked intriguing - I wanted to dig right in!

It's kind of a shame that the FAA doesn't distinguish between piston and turbine in the powerplant certificate. All the turbine engine stuff is going to be a waste for me, at least in my current thinking. It's hard to imagine how I could ever end up working on a jet engine. It'll still be interesting, though, and I guess there's no big hurry on the ratings. That said, considering what the classes cost, if the jet stuff was optional I wouldn't take it.

The administrator of the aviation program is coming to talk to us next week about scheduling. Since there are so few night students (the school takes a loss at anything under 13 students), he wants to talk to us about what classes to schedule for summer quarter to keep us all enrolled. I'm not sure what I want the most. Electrical would be the most useful when I start to build the new panel, but I already had that weekend class in October, and I think I learned everything I need to know to at least get started on the that. The one that I think I'd really like is aircraft structures. That's a big one - it takes two quarters to finish. I want to take it before they drop the fabric covering aspect of it, which they are talking about doing in the near future. It also covers construction techniques for sheet metal and composites, and I believe there's a section on welding too. I've always wanted to learn to weld, so that will be fun. If the rest of the class agrees, maybe I could take it for summer and fall.

1 comment:

  1. "tactilely exuding an aura of supreme confidence" I love it. It shows supreme confidece in the literacy of your readers. At first I wondered if that's what it said on the box the instrument came in, or maybe the instructor held it up exclaiming, " This here gizmo is made to tactilely exude an aura of supreme confidence if youse guys can figure out how to use it." But wherever the description came from it's right on according to my dictionary. I find your discussions very illuminating and interesting.