In
those days (I can't imagine it's like that now) all seventeen of us in Quality
Control wore suits and occupied a personal desk in a large first-floor office,
using our own private tools to dismantle and inspect the items placed in front
of us. One day I received a package
containing two Axle Maxarets from a small German airline. The attached label
was quite clear and simple: "Rough & grinding": And so it proved, setting my teeth on edge as
I turned the shaft, so out came the tool-kit to dismantle the first one. The Axle Maxaret was a very simple device -
about the length of a Christmas cracker, but twice the diameter, fitting neatly
inside the axle of the aircraft undercarriage. Not much more than a cylindrical
lump of lead driven by a sun and planet gear chain, it opened and closed a
hydraulic valve controlling the brakes as the rotating weight either overtook
the wheel, or got left behind.
Opened
up, the cause of the "graunching and grinding" was immediately
obvious. All three of the planet gears had their teeth milled off-centre,
over-cut on one side, gradually disappearing to nothing diametrically
opposite. Out came the drawing to show a
requirement for a VERY tight tolerance, requiring EVERY single gearwheel to be
checked on a fixture on which was mounted a clock micrometer. Clearly, none of the gears in these two units
had been checked as required, so the next step was to visit the vast machine
shop and find the appropriate inspection bench. Sure enough, there was a substantial
mound of these small gears piled up in front of a cow-gowned inspector
laboriously checking each gear over three pins using a micrometer in
time-honoured fashion. When I commiserated with him over his labour of love and
asked where the specified inspection fixture was, he told me that he had never
seen it in the three years he'd been doing the job. The next step was to see
the Machine Shop Superintendent - a very proper, large, and somewhat formidable
character who always called me Mr Nurcombe on the basis that he might have to
give me a proper rousting one day - in his glass office at the centre of the
vast machine shop. After revealing the
samples grasped in my palm I trotted behind him across the machine-shop as he
strode briskly between the machines. From now on I was merely a spectator.
After a quick glance at the table with the pile of gears, he called out to the
machinist who had been lurking unseen behind his machine, and who clearly knew
what was coming. "John, bring me your mandrel." and, very sheepishly,
a worn home-made mild-steel tool was handed over.
Now
all was clear. The two operatives had done the best they could - by their own
lights - to keep production going, and in that respect could only be commended.
What they SHOULD have done, of course, was to stop the job until the correct
equipment was supplied.
And
where was that precision hardened steel mandrel and the inspection
equipment? It took me less than three
hours to find them on a shelf in the wrong Tool Store where they had languished
for some three years.
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