Bustednuckles

I don’t even know if it’s a skill or an art form anymore.

Digging out broken bolts.

Every mechanic’s nightmare.

I’m petty sure I’ve dug, drilled and EZ-Outed at least a hundred by now over the years.

I just got to do it again tonight at work but this one was especially fun.

Not only did 3 of then shear off, one of them actually twisted sideways in the hole doing it.

That is one of 3 bolts holding a sprocket on to a Pneumatic clutch/Brake that drives the rollers on a big In feed table for a huge Vertical Band saw.

The clutch/brake looks very similar to this,

It’s connected to the electric motor at the bottom right of a table like this,

Ours was made in Canada.

Whoever built it was so proud of their work that there are zero identifying marks on it. No Name Plate, Model or Serial number anywhere.

And the clutch doesn’t actualy Clutch, like it’s supposed to.

The springs in it are too stiff.

The Rocket Scientists where I work set 20-40 foot long I beams on it.

BIG ONES.

The load limit is supposed to be 4,000 pounds.

They regularly drop 10,000 pounds worth on it.

The problem arises when they use the big Magnetic Spreader Bars and drop them on the table while the load is still traveling.

The Spreader Bar with Magnets looks something like this on the right.

Now back to the clutch brake,

There are only THREE, 1/4 X 3″ bolts holding that sprocket on.

A little smaller than the diameter of a Number 2 Pencil

Savvy?

Let’s do the math. 3 quarter inch bolts and they are dropping 10,000 pounds on the table while the load is moving.

Shears those fucking bolts off instantly.

As a matter of fact, this is the 5th time that I know of that they have done this, just to this one clutch/brake.

I spent FIVE HOURS getting the Clutch brake off, apart, drilling and digging the broken bolts out of the sprocket and fixing the holes. Then putting it all back together and re-installing it on the machine. Just so the dumb sonsabitches can do it again tomorrow or the next day.

When that little bolt broke and twisted sideway it fucked the hole up pretty good so I had to fix that too, after I finally got the bolt out.

I had to put the sprocket in a vise, take a 5/16 pin punch and a Ball Peen hammer and drive that hump back down and the use a needle file to smooth out that inner diameter.

Then run a tap down all 3 holes.

I broke the tips off of 2, 1/8th inch Carbide drill bits in the bolt and had to dig them out with a pick and a blow gun, then finish drilling through it with a standard drill bit. Of course then the hole was off center because the thing was in there sideways so after I got the hole opened up, I stuck a straight 1/8th Carbide Burr bit in a cordless Dremel tool and proceeded to use it like an End Mill to grind enough of the bolt away so I could dig what was left out with a pick, THEN fix the hole.