Here's a question for you gagemakers and tool and die makers.

At work, I had to make a go/no-go gage to measure a production tool
(precise welding electrode). The electrode has a set screw for
adjusting the length. The nominal length and tolerance of the
electrode is 57.50 +/- 0.50 Meaning that length should fall between
57.00 to 58.00 It is very critical that the length doesn't go below
57.00 nor exceed 58.00 Normal machine operators would be adjusting the
lengths using this go/no-go gage. I was afraid that the machine
operators would adjust the electrode lengths a little bit out of
tolerance. (My experience in the past led me to that conclusion.)
Therefore, I made a go/no-go gage that measured 57.10 to 57.90 This
ensured that the electrodes would not go out of tolerance if the
operators had a little error in measuring the tool. And this method
worked perfect. My tool and die maker partner insists that I should
have made the gage to the true tolerance regardless of the operators
using them. I disagreed.

Is there a particular name for this type of gage that I made? It
doesn't measure the true tolerance of the electrode. Is designing this
type of gage a bad method for gagemaking, or is it a common one in the
industry?

wrote in message
ups.com...
Is there a particular name for this type of gage that I made? It
doesn't measure the true tolerance of the electrode. Is designing this
type of gage a bad method for gagemaking, or is it a common one in the
industry?

Tool making isn't really "an* industry. There are many different industries
which employ the use of tooling and the tooling typically conforms to that
industry.

For instance, I work in automotive while others here work in aerospace. From
what I've seen, we speak different languages. These two industries have many
of their own standards to which tools are built. That's not to say that
certain standards wouldn't be applicable in several industries, but it's not
quite that simple.

As far as your gauging issue is concerned, ideally gauges should allow all
"good" parts to pass while failing all "bad" parts. Do you have a high scrap
rate using the gauge you've designed? I'm not sure, but it sounds like there
would be a name for the type of gauge you've made. One that allows the
operator to adjust the machine settings *before* producing a bad part. You
should, however, not be using this gauge to pass or fail parts. It should be
used only as a guide to keep the machine within tolerance. You should have
another gauge used for pass/fail, especially since your current gauge is
entirely incapable of passing/failing parts correctly.

Given that this part sounds like the tolerance is pretty open (+/-.5mm), if
you're not having trouble making good parts then what's the difference?

The above is worth exactly what you paid for it. YMMV.

Regards,

Robin

Robin S. wrote:

Tool making isn't really "an* industry. There are many different industries
which employ the use of tooling and the tooling typically conforms to that
industry.

Sorry for the minor technicality. I guess I meant "trade"...? Would
that be a better word?

Given that this part sounds like the tolerance is pretty open (+/-.5mm), if
you're not having trouble making good parts then what's the difference?

My point exactly! I guess I'm having a hard time convincing my
partner. He's extremely technical when it comes to these things.

wrote in message
oups.com...

Given that this part sounds like the tolerance is pretty open (+/-.5mm),
if
you're not having trouble making good parts then what's the difference?

My point exactly! I guess I'm having a hard time convincing my
partner. He's extremely technical when it comes to these things.


Remember that I don't know all the details of your situation. Tool makers
should be pragmatists. If this gauge is allowing your part to be produced as
efficiently as is possible then you're good. As I said before, you do have a
pass/fail gauge, right?

There may be other reasons why your partner is insisting on a standard
gauge. You should find out what his reasons are. You haven't given us enough
information to give you a black and white answer, as if such a thing exists
in this trade anyway.

Regards,

Robin

On 12 Apr 2006 15:53:05 -0700, wrote:

Here's a question for you gagemakers and tool and die makers.

At work, I had to make a go/no-go gage to measure a production tool
(precise welding electrode). The electrode has a set screw for
adjusting the length. The nominal length and tolerance of the
electrode is 57.50 +/- 0.50 Meaning that length should fall between
57.00 to 58.00 It is very critical that the length doesn't go below
57.00 nor exceed 58.00 Normal machine operators would be adjusting the
lengths using this go/no-go gage. I was afraid that the machine
operators would adjust the electrode lengths a little bit out of
tolerance. (My experience in the past led me to that conclusion.)
Therefore, I made a go/no-go gage that measured 57.10 to 57.90 This
ensured that the electrodes would not go out of tolerance if the
operators had a little error in measuring the tool. And this method
worked perfect. My tool and die maker partner insists that I should
have made the gage to the true tolerance regardless of the operators
using them. I disagreed.

Is there a particular name for this type of gage that I made? It
doesn't measure the true tolerance of the electrode. Is designing this
type of gage a bad method for gagemaking, or is it a common one in the
industry?
Greetings Jody,
You named it correctly yourself. Go/No Go. As far as the dimensions
go, either leave the dimension off, or make the gauge with the tighter
tolerance dimension stamped on it and tell the operator why. But don't
make it to one dimension and mark it with another. It is common for
people to fudge things a little to make up for losses which may occur
in the processing of the material(s). E.G. you need to make a part 2
inches long. You make a sketch with the part length shown as 2.125 and
send it to the saw shop. Your sketch is meant to provide you with a
part with enough material to clean up. The saw operator gets the
sketch and cuts the part to 1.25 because he thinks the sketch is the
finished length. This kind of thing happens a lot. Extra doodads get
ordered, electroplate prior to grind gets thicker, etc. Be sure then
to make the gauge the way it needs to be to insure good parts but make
sure everyone using the gauge knows why it deviates if it does indeed
deviate. And any marks should accurate descriptions.
Cheers,
Eric R Snow,
E T Precision Machine

wrote:
Here's a question for you gagemakers and tool and die makers.

At work, I had to make a go/no-go gage to measure a production tool
(precise welding electrode). The electrode has a set screw for
adjusting the length. The nominal length and tolerance of the
electrode is 57.50 +/- 0.50 Meaning that length should fall between
57.00 to 58.00 It is very critical that the length doesn't go below
57.00 nor exceed 58.00 Normal machine operators would be adjusting the
lengths using this go/no-go gage. I was afraid that the machine
operators would adjust the electrode lengths a little bit out of
tolerance. (My experience in the past led me to that conclusion.)
Therefore, I made a go/no-go gage that measured 57.10 to 57.90 This
ensured that the electrodes would not go out of tolerance if the
operators had a little error in measuring the tool. And this method
worked perfect. My tool and die maker partner insists that I should
have made the gage to the true tolerance regardless of the operators
using them. I disagreed.

Is there a particular name for this type of gage that I made? It
doesn't measure the true tolerance of the electrode. Is designing this
type of gage a bad method for gagemaking, or is it a common one in the
industry?

Speaking as a former (10 yrs) gagemaker, technically your partner is
incorrect. Normal gagemaking practice for your application would dictate
a GAGE dimension of 57.0 mm (+.05mm/-0mm) for the GO, and 58.00 mm
(+0mm/-.05mm) for the NOTGO gage.

However, your method is the way many Q.C. departments set the
tolerances, so as to ensure (in their minds) a higher probability of not
having as much scrap, and of the ones that fall outside THEIR
tolerances, many are still good to the print tolerance.

Actually, what they are accomplishing is covering up unskilled (or
unethical) operator inspections, by causing more questionable parts to
be diverted to their attention.

HTH

Robin S. wrote:
There may be other reasons why your partner is insisting on a standard
gauge. You should find out what his reasons are. You haven't given us enough
information to give you a black and white answer, as if such a thing exists
in this trade anyway.

The only reason my partner insists on a standard gage is for the reason
I gave in my original post.

I'm a tool and die maker. I don't make gages everyday like a gage
maker would. I'm relying on a gage makers knowledge here. I know
their knowledge is far greater than my own when it comes to gage
making. Therefore, I was in hopes that a gage maker would help me out
in their lingo and strategies in gaging parts. Which is what happened
when the other posters replied.

I feel like I've given all the information that I can about this
situation. If you have a question pertaining to potential information
I havn't given, then please ask.

wrote in news:1144882385.232988.26930
@u72g2000cwu.googlegroups.com:


Is there a particular name for this type of gage that I made? It
doesn't measure the true tolerance of the electrode. Is designing this
type of gage a bad method for gagemaking, or is it a common one in the
industry?


In automotive, it would be considered a 'production gauge or production
tolerance'. But it should be so marked. In many applications a
'production gauge (or tolerance)' is used and tolerances are based on
machine capability, or historical +/- 3 sigma SPC data for that
operation. Most times, this tolerance is well inside of the 'print'
tolerance. In our situation, it is not used to help 'sort' parts, but
rather to force the process to remain centered within the tolerance
window.
As stated by another poster, this also has the benefit of helping to
ensure that a possible scrap producing situation is corrected prior to
any actual scrap being produced.
For us this works well, we currently have a roughly 1.7 PPM average
(parts per million) rejected by the customers. This is on parts with many
micron level tolerances. Production in-house scrap rates are on the
average of 0.8% on part volumes in the millions.


--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

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In article . com,
wrote:

At work, I had to make a go/no-go gage to measure a production tool
(precise welding electrode). The electrode has a set screw for
adjusting the length. The nominal length and tolerance of the
electrode is 57.50 +/- 0.50 Meaning that length should fall between
57.00 to 58.00 It is very critical that the length doesn't go below
57.00 nor exceed 58.00 Normal machine operators would be adjusting the
lengths using this go/no-go gage. I was afraid that the machine
operators would adjust the electrode lengths a little bit out of
tolerance. (My experience in the past led me to that conclusion.)
Therefore, I made a go/no-go gage that measured 57.10 to 57.90 This
ensured that the electrodes would not go out of tolerance if the

If it's possible (don't know without seeing the setup) I might suggest
an additional "setting jig" that is 57.50mm to use for the setting
process (loosen set screw, use setting jig, tighten set screw, use
go/no-go gage to check.) I would agree with your logic in having some
margin on that gage, and with others in marking the gage to reflect that
and explaining the logic to the production floor personnel who will be
using it.

--
Cats, coffee, chocolate...vices to live by

I'd kinda sit on both sides of the fence on this one. If you mark the gage
with the dimensions, you want to build it to those dimensions. On the other
hand, if you mark the gage with a number and call out using the gage with
that number on it. you can put any dimensions on that gage without the
operator knowing what the gage actually measures. This also means that you
take the dimensions of the part sticking up from him at the same time so he
can't use a regular measuring tool to check his work. You also need to be
keeping track of the gages built so taht in the case of changing the
dimensions, you can change all of the gages at the same time and nobody can
argue with the results of the gage change. You also need to mark the work
in progress for reworking in the case of tighter tolerances.

--
Why do penguins walk so far to get to their nesting grounds?