It was time to go to work on my first screw. And there I got my next lesson. It was a real big screw, as they go, a 4-40 flat head machine screw with a length of about three-quarters of an inch. I would have to give it thirty turns to back it out. I never gave it the first turn. The head snapped off as soon as I applied a few inch-pounds of torque.
Yes, the surface had heated up nicely, but the shank of the screw was about two hundred below zero centigrade, and far brittler than glass.
I cussed some and reported to Sid what had happened.
"Have to drill it out," I said.
My drill was a cutie. It was a modified dentists' drill, the kind that's run by a little air turbine at about two hundred thousand r.p.m.'s. I really mean that. They turn like mad.
I'd been taught to use it with care. When a dentist drills your teeth, he blows olive oil and water through the turbine, and the mixture cools the tooth—and the drill—while the cutting is going on. We couldn't afford any cloud of vapor—or the shorting out that ice would cause—so I had only the pressurized mixture of oxygen and helium in the tanks on my back to run the drill. And that meant light and intermittent pressures on the number 43 wire gauge drill—the one that's the right size to drill out a 4-40. It took me about fifteen minutes and I was down to my last number 43 drill bit when she broke free.
From then on I had to heat each screw before I went to work on it. I had something like a soldering iron that I could press against the screw-head. Heat would flow through the highly conductive alloy and make it less brittle. I flicked each screw I removed out into space and at last carefully hinged the gate wide open.
The gate was the length of the sector—about two feet. It was four inches wide and about an inch thick and had parts strung along it like kernels on an ear of corn.
At this stage I readjusted the position of my webbing girdle until I could clamp my head in position and begin the testing. It was slow work. The first sad thing was to learn that the solenoid M1537 was as good as new. When I put enough voltage across its terminals, the actuator clicked down through the core.
I swore a blue streak.