How Important Is Hitting That Size?

[rake60]

Being hobby machinists we have the luxury of missing a size.
After a few minutes of beating ourselves up, we give the errant
piece a toss and try it again. That is what makes the hobby
machining thing a relaxation event.

At work I was often called on to fill in for the shift foreman.
One night will stick in my memory forever.
There was a truck in the parking lot with the engine running waiting
for a gear reducer frame to be finished. My best buddy Boo was operating
a horizontal boring mill machining the last fits. I was there to help him along.
He took a finish cut on a bearing fit in the housing and took a mic reading.
His face tuned a little red and he checked it again.
He looked at me and SCREAMED, "That's no F$(&IN good!".
For whatever reason, that struck me as being terribly funny and I
collapsed laughing on the table of the mill. Then Boo started laughing at
me but pointed out that the truck was waiting to deliver the frame.
I told him that it was a weld repair that we could weld again.
If it took a couple extra hours to complete it would not effect the sun
coming up in the morning. On the second attempt, Boo hit the size and
the truck was loaded 2 hours later than anticipated. I happened to know
a maintenance man who worked for the company we were reworking that frame
for. I met up with him 6 months after that incident. Her said, "Yeah I know the
frame your talking about. We changed it out last month."

Boo's devastating moment of defeat was 5 months in advance of it's critical need.

So how important is a missed size?
On an ego scale it may be very high.
On a reality scale, "It Don't Mean Nothing!"

Rick

 

[JimN]

And that is a fact, thanks for posting.

 

[vlmarshall]

Great story, thanks for sharing it.

 

[gbritnell]

I think this is one of those topics that could get a little personal. Everyone has their own feelings about everything, not just this topic. How we accomplish things has to do with many factors, family upbringing, attitude and work ethic to name a few. It's like trying to convince someone to buy a Chevy when they've owned Fords all their life. Whatever you're good with is my appropriate response.
gbritnell

 

[mu38&Bg#]

Maybe you've never dealt with the auto industry. They give you a tolerance, but you are only allowed to use 60% of that tolerance. If you manage to let more than 1 in 1 million parts to the factory floor that are out of tolerance, you have serious problems. If it's more than that, suits visit you to talk about how many defective cars you're buying back.

It' all depends on who the customer is. And, if you are your own customer it's easy to be lenient ;D

Greg

 

[bearcar1]

And yet another reason they developed the shotgun in the firearms industry. Some folks just don't have a very good aim. :big:

BC1
Jim

 

[Krown Kustoms]

Rof} Rof} Rof} Rof} Rof} Rof}

I guess I use a shotgun in the shop.
-B-

 

[Tin Falcon]

The home shop is like a college engineering lab no mistakes just learning experiences.
They are not mistakes they are "Design changes"
That was not a missed tolerance that was a practice piece.
That is not a scrap part i was experimenting with that one.
If it fits and the engine runs it must meet specs.
.........
Tin

 

[GWRdriver]

for. I met up with him 6 months after that incident. He said, "Yeah I know the frame your talking about. We changed it out last month."

The REST of the story . . . .

"Yeah I know five months delay is a long time, but somebody at your place ignored our specified delivery schedule and by the time we got it from your shop the person who knew how to install and test run it had just gone off-shift. Our other men weren't told and didn't know that a bearing repair needed a run-in and a built-up weld failed during the next shift and wrecked the whole frame. We had to shut down a line and send it to the manufacturer for a rebuild but it was beyond repair and we had to have a whole new frame built and that cost the plant over $100,000 and over a million in lost production. That killed our year, not to mention losing our best customer because we couldn't meet production schedules, and as a result we had to lay off a full shift and none of the rest of us got raises or production bonuses. The Boss ordered us not to send any critical work to your shop again. Oh BTW, sorry to hear your shop is closing. Too bad. You guys used to do good work."

 

[rake60]

Interesting story Harry.

Those things do happen.
Poorly trained people in the end users shops often do result
in blame being placed on the primary machining companies.

That is a sad issue but one one that deserves mention.

Rick