Geometric Dimensioning and Tolerancing
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Re: Geometric Dimensioning and Tolerancing
Re: Geometric Dimensioning and Tolerancing -- hepmisafir	Post Reply	Top of thread	Forum

Posted by: Kelly Bramble ® 08/30/2006, 12:12:46 Author Profile eMail author Edit

I am not sure what you are asking. GD&T is just a drawing langauge used to express tolerance requirements. Tolerance requirements are based on functional requirements and manufactuability capabilities. Modified by Kelly Bramble at Wed, Aug 30, 2006, 12:13:11

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Re: Re: Geometric Dimensioning and Tolerancing
Re: Re: Geometric Dimensioning and Tolerancing -- Kelly Bramble	Post Reply	Top of thread	Forum

Posted by: traingdt ® 08/30/2006, 18:01:44 Author Profile eMail author Edit

If you are saying that a tolerance range was indicated, that is unusual; perhaps it is meant to indicate "bonus" tolerance on the 0.02 (this happens with the MMC or LMC modifying symbol). But to determine a tolerance, there are many factors. The bottom line is fit and finish. One useful formula is "virtual condition," which is a number that represents the "worst-case" size and geometric tolerance together. For example, if a hole has a size range of 9.7 - 10.3 and a position tolerance of 0.2 at MMC, then the virtual condition is 10.1. This is the imaginary circle created by the smallest hole that is also at its positional extreme. So now, a mating pin would have to clear through 10.1 mm. In fact, the mating pin's virtual condition would be 10.1, and we could work backwards to design its size and position tolerance to fit that virtual condition. Hope that helps...

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Re: Re: Re: Geometric Dimensioning and Tolerancing
Re: Re: Re: Geometric Dimensioning and Tolerancing -- traingdt	Post Reply	Top of thread	Forum

Posted by: WDTH_toolDev_Eng ® 09/11/2006, 02:30:56 Author Profile eMail author Edit

Kelly is right.

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Re: Re: Re: Re: Geometric Dimensioning and Tolerancing
Re: Re: Re: Re: Geometric Dimensioning and Tolerancing -- WDTH_toolDev_Eng	Post Reply	Top of thread	Forum

Posted by: traingdt ® 09/11/2006, 21:29:11 Author Profile eMail author Edit

I made a math error on my response to this question. The example I used would result in a "virtual condition" of 9.5, not 10.1

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