Rounding of Dual Dimension Tols?
Rounding of Dual Dimension Tols?
(OP)
If my primary dimensions are in MM and my secondary dimensions are INCHES in dual dimensioning, if I have a tolerance of 0.05mm it shows as 0.001" instead of rounding up to 0.002". Is there a way to fix this?
RE: Rounding of Dual Dimension Tols?
You can either increase the primary tolerance to .051 mm which will round to .002" or increase the number of decimals on the secondary units to 4 in which case .05 mm will round to .0019".
RE: Rounding of Dual Dimension Tols?
RE: Rounding of Dual Dimension Tols?
Dual dimensioning is almost always a mistake IMHO.
RE: Rounding of Dual Dimension Tols?
Secondly, I should point out that dual dimensioning is no longer supported by ASME, prolly for reasons like the ones mentioned in this thread.
Personally, I would pick one set of units and stick to it.
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: Rounding of Dual Dimension Tols?
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: Rounding of Dual Dimension Tols?
Thanks for the summary of what's wrong with the secondary, that totally makes sense why they don't round up as you wouldn't want the parts to be accepted at a higher tolerance than you intended.
RE: Rounding of Dual Dimension Tols?
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Fighter Pilot
Manufacturing Engineer
RE: Rounding of Dual Dimension Tols?
I agree you can't always avoid them but they are still a problem waiting to happen. I find increasing the number of decimal places is the best thing to avoid roundoff error. And always use explicit tolerances rather than default tolerances as they can really bite you.
RE: Rounding of Dual Dimension Tols?
The reason my company uses them is the projects and parts are always time critical, they never want a part to come in late only because a machine shop tried to convert them from metric to english and someone made a calculation error... sure it's their fault but my company will still have to pay in the end due to the project being delayed...
now you'll say "find a company that can do metric" and I say, go run your own business.