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Can I report my employer for incorrect quality practices?

CarbideBob

Diamond
Joined
Jan 14, 2007
Location
Flushing/Flint, Michigan
I have posted this here before but will ask.
Is "feel" on a gauge block being all nice and flat different than "feel" on a turned or ground shaft?
Is this worse with calipers as the nice block sort of squares up the jaws when checked?
 

CITIZEN F16

Titanium
Joined
May 2, 2021
Ages ago at a place I worked the guy running two CNC chucker lathers had to cut up his own stock on an automatic saw.
To check the slugs he kept a pair of Chinese digital calipers sitting by the saw, depending on how hard you squeezed them the total variance was .010.
 

Milland

Diamond
Joined
Jul 6, 2006
Location
Hillsboro, New Hampshire
I have posted this here before but will ask.
Is "feel" on a gauge block being all nice and flat different than "feel" on a turned or ground shaft?
Is this worse with calipers as the nice block sort of squares up the jaws when checked?

I'd say there's a difference, and there can be a lack of parallelism in the jaws as lapped. But you can mitigate this a bit if you measure just the "corner" of the gage block, and at a few different heights along the jaws. Or use a couple "X" class plug gages.

Almost always worse with the inside jaws, so I check just the tips and then down a bit in the setting ring.

Last, be sure the gib screws on the slide are adjusted correctly, that's a classic source of error.
 

eKretz

Diamond; Mod Squad
Joined
Mar 27, 2005
Location
Northwest Indiana, USA
I have posted this here before but will ask.
Is "feel" on a gauge block being all nice and flat different than "feel" on a turned or ground shaft?
Is this worse with calipers as the nice block sort of squares up the jaws when checked?

Yes it sure is, depending on the tool being used and the pressure being applied. Think about it this way: pressure per square inch. You have the entire anvil of a mic in contact on a flat part. Only line contact on a diameter - assuming it's perfectly parallel. Equal force will compress one farther than the other. That's the nice thing about low pressure or non-contact measurement methods.
 

barbter

Diamond
Joined
Oct 27, 2007
Location
On Tour...
I have posted this here before but will ask.
Is "feel" on a gauge block being all nice and flat different than "feel" on a turned or ground shaft?
Is this worse with calipers as the nice block sort of squares up the jaws when checked?

You know the answer is yes....
 

michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
QT: [measure parts that require a +/- 0.001]
That is a big tolerance even for a not the best way, Caliper.
Measuring takes time and likely the boss knows what this customer wants and is accustomed to.

The worker can't analyze everything in the shop.

Just for practice, one could measure the same JoBlock ten times to see if the measuring tool will make spec.
 

mhajicek

Titanium
Joined
May 11, 2017
Location
Minneapolis, MN, USA
I have posted this here before but will ask.
Is "feel" on a gauge block being all nice and flat different than "feel" on a turned or ground shaft?
Is this worse with calipers as the nice block sort of squares up the jaws when checked?

Check your feel with gauge pins then.

Ages ago at a place I worked the guy running two CNC chucker lathers had to cut up his own stock on an automatic saw.
To check the slugs he kept a pair of Chinese digital calipers sitting by the saw, depending on how hard you squeezed them the total variance was .010.

You can do that with an abused Mitutoyo too. If my cheap Chinese calipers loosen up (from being dropped or getting chips in the gear rack) and I can't get them to repeat well enough anymore, I relegate them to the saw and buy a new one. That said, not all Chinese calipers are created equal; I probably got lucky finding ones that don't suck.
 

Kalispel

Aluminum
Joined
Jan 27, 2021
Location
Ohio
There are no ISO quality police. Your company might be held accountable by the customer. Internal rejections might get more expensive later in the process.

The exception where you may have a reporting obligation is if you are doing certain or regulated work. Never lie or fabricate data.
 

gbent

Diamond
Joined
Mar 14, 2005
Location
Kansas
I have posted this here before but will ask.
Is "feel" on a gauge block being all nice and flat different than "feel" on a turned or ground shaft?
Is this worse with calipers as the nice block sort of squares up the jaws when checked?

Its why I always liked the old Brown & Sharpe calibration standards for smaller mics. They were a short section of round shaft, rather than a shaft with square ends. Yaw lock is easy to get, and is often .0002-.0005.
 

michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
ISO requirement would not discourage the use of calipers for checking a +- .001 part. ISO would require the calipers are calibrated on a timely basis so if not dropped or abused the company-provided calipers should be good/acceptable for this task.

Training and qualification are mentioned so likely the boss knows that a caliper check would be acceptable.

If the boss suggested a caliper check for a .000050 spec then his level of training and qualification would/might be in question.

I think it would be out of line for the Op to report wrongdoing in this simple situation. He could express his opinion to the boss, and hopefully get a polite expiation from the boss..and so be the end of it.
 

eKretz

Diamond; Mod Squad
Joined
Mar 27, 2005
Location
Northwest Indiana, USA
Its why I always liked the old Brown & Sharpe calibration standards for smaller mics. They were a short section of round shaft, rather than a shaft with square ends. Yaw lock is easy to get, and is often .0002-.0005.

I like to check with the same geometry as whatever I'll be measuring - so flat standards or gage blocks when measuring flat, gage pins when measuring round, etc. The tough part comes when you only have the opposite to the one you need. I have tried measuring both shapes at the same size and repeatably come up with a 1-2 tenths difference. Not enough to worry about for most stuff I do.

A good way to avoid that "yaw" or a cocked standard with flat ends is to rotate the standard slightly while you're closing down the mic. They will generally sit nice and flat every time that way.
 

greif1

Aluminum
Joined
Oct 1, 2013
Location
Rochester, NY, USA
If the calibration system that the caliper is checked with, allows +/-0.001" for the caliper and the part spec is +/- 0.001", you have used up the entire tolerance on the caliper and will never know if the part is in or out.

Yes, I agree with the folks that said if you use a gauge block the same size as the aim size (or even better one at low spec and one at high spec)and zero the caliper on them, you are now using the caliper as a differential gauge, which eliminates a lot of error.
 

Mike1974

Diamond
Joined
Nov 5, 2014
Location
Tampa area
Maybe you can calibrate your own feel against a standard or CMM, but you cannot run a plant on feel alone :). Hence CMM beats them all, I guess CMM just does not give a shit about feel-ings

Yes, but just like a PC, garbage in = garbage out.
 

michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
If the Op asked if this is the best practice then most answers given would be appropriate, but asking can I (should I) report this that answer should be no.
With .0005 calipers where does the boss draw the line, at the +- .0005 space or at the next .001 space.

Certainly, with go/no gauges or a better gauge device he could go to +- .0008 with reasonable safety..but that was not the question.

If the boss knows that an extra .0005 is acceptable to the customer then to the .001 place is a management decision...and going to the .001 place would be no problem.
 

michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
Quote Originally Posted by dcsipo View Post
Maybe you can calibrate your own feel against a standard or CMM, but you cannot run a plant on feel alone . Hence CMM beats them all, I guess CMM just does not give a shit about feel-ings

I used to equal the CMM with a plate check and my best indicator, and/or with my indicator micrometer off my Jo block set. It really bugged the inspector because he loved to tell me how many millionths I was off like that was a mile... even on a +- .0002 part.

I gave it up when he said, "Wow Buck you must fallen asleep being 12 millionths off, so I brought out my big guns.
 
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