On Tuesday, December 4, 2018 at 1:59:29 PM UTC-5, Fox's Mercantile wrote:
On 12/4/18 11:15 AM, ewhidbey wrote:
I figure it was a cosmic ray.

When I was doing CNC repairs at Northrop Aircraft, I had
an odd problem with a Pratt and Whitney Starturn lathe.
They had these HUGE 3" x 18" helical wound resistors for
the spindle braking. Because of the current, the winding
wound bounce like a Slinky toy. Eventually breaking off
the ceramic nubs on the form. So when they'd apply the
spindle brake, the turns would short out and arc. Add
that to the crap job the machine installer did with the
grounding and you have a major problem.

So, one night, the operator is most of the way through
making a 6" diameter hydraulic coupling. The machine
forgot to recenter a boring bar and went to rapid retract.
Nice, but it pulled the part out of the chuck while it
was turning at a high rate of speed.
After making 5-6 full loops around the inside of the
safety cover, if finally found the sweet spot, exploded
the glass and took off past the operators head and through
the wall behind him.

On the other side of the wall, it found a 36" Blanchard
grinder and hit the wheel, breaking it. The next thing to
happen was a seriously off balanced grinder trying to hop
across the shop until it ripped it's wiring apart.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

You have all the fun.