Re: Positional tolerance question

Garlicdude <pulsar@xxxxxxxxxx> wrote in
news:42F17892.22710C9A@xxxxxxxxxx:

> Bing wrote:
>>
>> BottleBob <bottlbob@xxxxxxxxxxxxx> wrote in news:42EFE59D.A789AA31
>> @earthlink.net:
>>
>> > DJ Bjorklund wrote:
>> >
>> >
>> >> In your typical "three place means +/-.005" situation is location
>> >> tolerance about the CL a function of the OD, .875 in this case,
>> >> thus +/-.005,...or even perhaps +/-.0025 ?
>> >
>> > DJ:
>> >
>> > I'm not sure it's safe to assume that a three place decimal is
>> > automatically a tolerance of +/- .005, even IF it's very common.
>> > Our satellite part prints call for +/- .002 on all three place
>> > dimensions, we also have a medical customer that requires +/- .001
>> > on three place decimals, and then we have another customer that
>> > allows +/- .010 for three place dims.
>> > There doesn't seem to be any industry wide standard for this,
>> > or at
>> > least none that everyone adheres to.
>>
>> Bottle,
>>
>> Not to be disrespectful to anyone here but did you read his original
>> post?
>>
>> Quote:
>> Not looking for a doctorial thesis on mechanical tolerancing, just an
>> opinion. We're machining fairly low-tolerance mechanical parts. A
>> machinist disciplined for NOT CHECKING HOLES ultimately discovered to
>> be off the center-line ~.025 makes the somewhat weak point that there
>> was "...no dimension, so what's the tolerance?!"
>>
>> End Quote
>>
>> Now I emphasized NOT CHECKING HOLES because thats where the problem
>> is.
>>
>> He DIDNT check it. And when he did he prolly knew he made a booboo,
>> so the POS took the easy road and blamed the engineer.
>> That to me is shitty work and a foobar attitude. He has no frickin
>> reason to blame HIS mistake on the engineer at all.
>>
>> What if he was off an inch? He gonna blame the engineer on that too?
>>
>> Honestly I cant believe some of the replies to this. In our shop we
>> have a standard for certain types of features, no matter if they are
>> called out onna print or a napkin drawing. And what are ya gonna do
>> when yer werkin onna 3d model that cannot be accurately dimensioned
>> to ANY standard? Alot of shops dont even use prints anymore. We dont
>> for some features. It has to be based off the supplied customer model
>> and they state so in their prints.
>>
>> Also, this seems to be an issue in Dale's shop not in anybody elses.
>> In other words they probably have their own internal standards and
>> being off a hole location by .025 is not acceptable.
>>
>> So, IMO I think the machinist is at fault not the engineer.
>> And, quite honestly I dont trust people that blame others for their
>> own mistakes.
>>
>> Bing
>
> Bing, I agree. With a tiny bit of care it should be easy to hold the
> centerline to plus or minus .005. The machinist, hate using that word
> for this clown, made a mistake in setup, then failed to check his
> setup and scrapped parts.
>
> In my shop I would prefer an honest, "I f&*^#% up", than a guy that
> tried to weasel out of it by blaming the drawing. The weasel would
> get the boot. The machinist that made the honest mistake and copped
> to it would stay, IF they didn't have a string of these to their
> credit.

Well, thank you. Fellow neo-con, perverted, uh machinist. Hey I am too so
WTF. :)

Ya know its the same mentality that some people had when I was in shops.
They want a merit raise, so they go in and dont say nothin about
themselves but say that some other guy sucks and he can do the job
better.

I gotta tell ya I dont have that shit in my shop and I dont like that
whole mentality.

Bing
.

Relevant Pages

  • Re: Positional tolerance question
    ... Bing wrote: ... >>> tolerance about the CL a function of the OD, .875 in this case, thus ... We're machining fairly low-tolerance mechanical parts. ... > to blame HIS mistake on the engineer at all. ...
    (alt.machines.cnc)
  • Re: THIS IS A CNC NEWSGROUP TRANSFORMED IN SHIT BY YOUR POLITICAL STUFF
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