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Re: Rounding in drafting

Siemens Phenom Siemens Phenom
Siemens Phenom

Some short examples can be found here.

 

Rounding Examples

 

Scott

Re: Rounding in drafting

Pioneer
Pioneer
It's hard to believe we're still having this conversation, as I had called in an oddball occurrence I experienced on a drawing back in the UGFM days in the 80s. I had sent in a part example where the left end width dimension of an extrusion didn't match that of the right, even though the ends measured exactly the same width. I only discovered UG had this left vs. right problem by chance when I changed the location where I had initially placed the dimension. This was way back in the BBS days, and yes, I seem to remember John was involved in this conversation back then, helpful as always. That problem was addressed and fixed in a later point release, but the same thread showed up again back in 2005. Here's a snippet: Re: Dimensional rounding Thanks for your help Daryl. I looked back and read the posts. Guess I need to start using the "Search" button more. Thanks again. Daryl Pierman wrote: >We've recently discussed this here ad nauseum. The software will >correctly round your .0625 value off to .062. Similarly, a value of >.0635 will correctly round off to .064. This rounding off method is not >only statistically more accurate, it follows various accepted standards >from both ANSI and ASTM. > >The rounding off takes place only when the discarded digit is exactly >5. In a nutshell, if your last significant digit is even (in your case, >the "2" in .0625) the depicted value rounds down. When the last >significant digit is odd, the depicted value rounds up. > >Unigraphics has done this correctly for a very long time. There was a >bug back in the late 80s related to this, but it was corrected. If you yourselves (or your kids) have been taught the wrong rules in school, bring the teacher a current copy of ASTM E 29 or a cancelled copy of the old ANSI Z25.1, and follow the advice of an old EDS guy (Ross Perot), "If you find a snake, kill it". It might be the only way John won't need to explain this anymore. Daryl (soon to be retired as well)
Daryl Pierman
Chief CAD Designer
Rocket Shop
Aerojet Rocketdyne

Re: Rounding in drafting

Siemens Phenom Siemens Phenom
Siemens Phenom

Yes, this came-up so often that back when I was still working I had a copy of my response as a Word document and whenever it was needed I could simply 'copy & paste' it into the appropriate forum where is was suddenly an issue again.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA