Tuesday, May 20, 2008

New Wine in Old Wineskins

For years, I've wanted an air compressor, but couldn't afford one. For many a year I limped along with a noisy emergency tire inflater, but practical it wasn't, and it was more tempting to drive with a nearly-flat tire than stand there in the midst of a sleepy neighborhood, trying somehow to suppress the racket. Then, about a year or so ago, my in-laws retired back to the U.S., and brought their household stuff back with them. My father-in-law offered us some of the things they no longer needed — including an electric cart, a large TV, kitchen chairs, the chassis for a new computer — and to my delight, an air compressor. They loaded up a trailer full and brought it all down from New Hampshire.

At first, I was not impressed. But then, I didn't really know what I was looking at, either. It was a caked mass of dirt on black and rusted mountings, with all sorts of strange canisters and valves. My neighbor, Chris, wandered over. "Wow," he said, "that's quite the compressor." At that point, I didn't know if he was being serious or sarcastic. My father-in-law had built this thing out of used parts when he was 16... he's 66 now. But he set to work on the thing, and when I returned home from work, he had it chugging away happily, filling up a new tank we had bought earlier with plucky ease and a cheery pocketa-pocketa that made me think of Walter Mitty.

If there was a fault, it was that it wouldn't run below 60°F. It puttered along just fine at warmer temperatures, but lower than that, the motor would strive vainly against the belt, spinning in place and ultimately shutting off. Unfortunately, Indiana spends about half the year below 60°F. (Even now, in the middle of May, I regret turning the furnace off.) So we set our minds to the challenge: How could we rework the compressor to work year-round?

At first, our idea was to simply put a larger sheave (pulley wheel) on the compressor, and just have it run slower. This was made difficult by the fact that the hole in the center was tapered, and the wheels available locally only had straight holes. What's more, we couldn't have gained more than half an inch of diameter without cutting the frame of the compressor to make room. Reluctantly, we set this solution aside.

So we embarked on a different solution: more power! My father-in-law advanced some funds, and we ordered a new motor from NorthernTool.com (which has now been added, along with Aerostich.com to my list of Very Dangerous Websites.) My father-in-law had to leave before it arrived, but we discussed our strategies, and waited eagerly.

It was a beaut. I rarely describe industrial equipment as lovely, but just the look and heft of this thing spoke of smooth, effortless power.

Unfortunately, the sum total of the included directions were (a) a small diagram on the side of the motor, and; (b) a warranty card that indicated that this product should be installed by qualified personnel. Unfortunately, "qualified personnel" does not include me. (Being the son, grandson, and son-in-law of three electrical engineers has not netted me any talent in this area.) Even so, between e-mailing photos back and forth and phone calls, we managed to get everything hooked up correctly.

To run at 220 volts, do nothing; to run at 110 volts, move the black wire to terminal 2. To blow all the fuses in the house, move the brown wire to terminal 3...

It took me 20 minutes to get the old motor off, and about 10 seconds to realize the new one had a different mounting pattern than the old one. I mounted it anyway.

Finally, the moment of truth arrived. All the wires and belts were in the right places, and I flipped the switch.

Looks like I'm going to have to move the air hose hookup, too.

Have you ever seen a race car do a burnout before the race? The wheels go a hundred miles an hour, but the car only goes three feet. That's what it was like. The motor pulley spun mightily against the belt, but the belt had no hopes of harnessing the power. There just wasn't enough traction. I tightened up the belt, but it just put a higher level of polish on the pulley.

So, still no all-weather air compressor. My next scheme involves fitting the old motor pulley (which had two channels) and putting on two belts. Twice the circumference, twice the belts should theoretically yield four times the traction... right?

Of course, the old pulley was for a 3/4" shaft, and the new shaft is 5/8", which presents a few challenges, but, I'm certain, not ones that haven't been solved before by thousands of other people.

We'll get it one of these days...

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