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 Post subject: I'm puzzled !
PostPosted: Wed Jul 13, 2016 8:24 pm 
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Location: Rochester MN USA
I'm puzzled about how much accuracy is too much. Also How complicated does "micro adjust" get and is it worth it? :confused:

I'm reminded of a story an engineer with a computer company once related to me. He told me that a young,newly hired, engineer working in his division once came to him and showed him a list of specifications for a project extending to 6 decimal places. He told the youngster that he appreciated his work and diligence but then asked him what were the tolerances that the machines they were going to use to make the product were. The newby told him that those particular machines could work to thousands of an inch. He said he smiled and walked away.


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 Post subject: Re: I'm puzzled !
PostPosted: Wed Jul 13, 2016 9:46 pm 
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Location: Hamilton, MS
[quote="newtooth"]I'm puzzled about how much accuracy is too much. Also How complicated does "micro adjust" get and is it worth it? :confused:

I'm reminded of a story an engineer with a computer company once related to me. He told me that a young,newly hired, engineer working in his division once came to him and showed him a list of specifications for a project extending to 6 decimal places. He told the youngster that he appreciated his work and diligence but then asked him what were the tolerances that the machines they were going to use to make the product were. The newby told him that those particular machines could work to thousands of an inch. He said he smiled and walked away.[/quote]

Yep. And for .0001 accuracy and beyond, you must have a climate controlled environment that the machinery, measurement instruments and work piece have stabilized in for at least several hours. Preferably a dedicated "clean room". The oil on your fingers, body heat, etc. can effect extreme accuracy requirements. There's a rigorous protocol for this kind of thing.

None of this is available in the WW world, nor is it necessary. About all you ever will find useful or doable is 1/64 inch (~ .016").


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 Post subject: Re: I'm puzzled !
PostPosted: Thu Jul 14, 2016 1:32 am 
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Location: Skagit Co WA
If it fits, it's accurate enough for me.


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 Post subject: Re: I'm puzzled !
PostPosted: Fri Jul 15, 2016 5:24 pm 
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I have a friend who needed a special bracket for his race car. He sketched it up and dimensioned it to about 6 decimal places, took it to a machinist and asked if they could make that for him. The reply was sure no problem!
"So about how much would it cost?"
"Oh about $36,500.00"
"Why so much?"
"Well, if you could remove about 4 decimal places on the dimensions, we could make it for around $15.00 :)".
He removed the 4 places and had the bracket built.....Live and learn. LOL LOL


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 Post subject: Re: I'm puzzled !
PostPosted: Tue Aug 30, 2016 5:48 pm 
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Location: Seattle, WA, USA
Hey Guys,

I guess that it's stating the obvious to say that just because you can make a precise fit, doesn't mean that you should.

For example, during the Soviet Great Patriotic War (WWII), the German trucks, tanks and artillery had a difficult time with the extreme cold. Their machined tolerances were so close that they malfunctioned when parts shrunk due to the temperature. In contrast, the Russian machines were machined to very loose tolerances, to the point that a casual observer might call them crudely done. However, when the Russian winter came, their machines performed as expected.

Cheers,
Tom

ps. Thank you Newtooth for picking up the puzzler. :-D

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