On Wednesday, June 24, 2015 at 10:32:25 AM UTC-4, Ed Huntress wrote:
On Wed, 24 Jun 2015 07:04:33 -0700 (PDT), rangerssuck
wrote:

On Tuesday, June 23, 2015 at 11:37:14 PM UTC-4, Larry Jaques wrote:
On Tue, 23 Jun 2015 15:05:27 -0700, Gunner Asch
wrote:

On Tue, 23 Jun 2015 16:39:06 -0500, Ignoramus9052
wrote:

On 2015-06-23, Gunner Asch wrote:
On Tue, 23 Jun 2015 08:47:22 -0500, Ignoramus9052
wrote:

On 2015-06-23, Gunner Asch wrote:
On Mon, 22 Jun 2015 23:02:16 -0500, Ignoramus8881
wrote:

http://igor.chudov.com/tmp/crankshaft.jpg


They abused the **** out of that crank. See the scoring on the driven
side?

No lube there in a long time.

Great observation!

This was from a punch press.

This is how most Chicago people use most equipment, in general.

i

Folks here seem to forget I work on and repair this sort of thing.
Machinery in machine shops Shrug. Its how Ive made my living for 20
yrs.

The folks that owned that press had zero maintainece. Even if they
were paying somebody. Having a crank that badly scored is clear
indication that sooner or later..somebody is gonna **** up badly
enough to bust that same crank.

What happened..die platten bolts break and the platten shift? That
wasnt a "crystalization" break of the crank..but a full power ****up.
Anyone get hurt when it all broke loose?

I have no idea, I simply observed that crankshaft on the ground, I do
not know the story. My guess is not much happened to the operator.

i

The older machines often had a BIG assed flywheel on that end of the
crank along with the brake. I was called in years ago on a repair job
for a crank that had crystallized and that 8' flywheel had suddenly
gotten free. No one was badly hurt..but the flywheel was found in the
street blocking traffic....embedded in the side of someone's
van...about 400 feet from the press. It damaged everything so badly
on the press..and the shop wall..and the front office wall..and the
wall outside of the building, and a motorcycle in the parking
lot......that they simply scrapped the press, moved in a new(er)
press, called in the carpenters, tow trucks and the insurance company
(s)......

http://midwestmachy.com/wp-content/u...6/DSC_0012.jpg
Is an example of the type of press that failed....

This is the biggest reason most..most presses today have hydraulic
rams instead of a flywheel. While more complicated...when they fail
catastrophically...they usually stay together....

That's vaguely reminiscent of the trailer spare tire which got away
while traveling down the freeway in LoCal...

--
Find out what people will submit to, and you have found out the
exact amount of injustice and wrong which will be imposed on them.
--Frederick Douglass

In a shop where I worked, a somewhat amusing lunchtime activity was taking clapped-out bearings, washing all the lube & dirt out of them, holding the inner race between thumb & index finger, spinning them up to some insane speed with an air gun & putting them down in the parking lot. They'd go some pretty impressive distances.

We can't let this trick go by without comment. First, if you turn the
bearing to the side while doing that, the gyroscopic effect will
side-load the bearing and likely burn your fingers, unless you
instantly let go, in which case the bearing will run off and hit
something at a very high speed.

If you put your finger through the shaft hole and it side-loads like
that, it may seize and rip off your finger. However, your finger will
have the ride of its life.

Third, if you succeed it getting it to spin up freely, you will,
eventually, learn about the fracture mechanics of hardened 8000-Series
steel, while the outer race explodes in your face.

'Just a caution.

--
Ed Huntress

This was all 40-odd (very odd) years ago, and I still have both eyes and all fingers are intact. But yeah, it was pretty nuts, but these things did go several hundred feet before hitting the building across the street.