Thursday, July 16, 2009

the task, the process, the reward

The Triggered Spark Gap Switch is nearing completion.

Not to be confused with Mad Scientist Light Switch, which not only is not nearing completion, it isn't even breathing hard.


Let's not talk about that.

For weeks now, the status of the spark gap has been: "complete except for: 1) locating grooves in the inside surfaces of the end caps to center the housing pieces and end caps on each other; and 2) drilled and tapped holes in the end caps for the gas fittings."

As of tonight, both grooves are done. One gas fitting hole is drilled and mostly-tapped. I say, "mostly" because the tap I have is a normal one, but this hole is a shallow one, and is for an NPTF fitting besides. I ground mine down a little (because a new _standard_ tap to replace it is cheap) but it wasn't enough. So I have a "short projection" NPTF tap en route. $14 grumble.

And the gas fitting holes turn out to be finicky. You see, I did not plan their locations vis-a-vis the available real estate inside the housing but outside the spark gap main electrodes. AND I didn't allow for screwing up the spark gap main electrode holes, so they currently require a nut and washer. That may change, but for now, the gas fitting holes have to be outside the washer.

That's about the right diameter if I do something terribly clever to make the nut and washer go away. We shall see what we shall see. Meanwhile, I had to put a little hole behind the back-side curve of each main electrode into the end cap, drill and tap the hole for the fitting quite a bit outboard of that, and then drill a small connecting holes between them, at an angle. I have done the first one successfully. I am, as they say, well chuffed.

I shall post a picture or two, another day.

Now I am going to consume about an ounce of Hennessy (Privilege VSOP, not the top of the line I know, but on the other hand, I can afford it. about once a year.) begin reading Yet Another Pratchett Distraction, and fall comatose within minutes.

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