Runout Tolerance always less than Dimension Tolerance?
Runout Tolerance always less than Dimension Tolerance?
(OP)
Does runout tolerance always need to be less than dimension tolerance? If bearing surface is dimensioned 1.0000 (+0.0003 -0.0000), then the runout tolerance can only be 0.0001?





RE: Runout Tolerance always less than Dimension Tolerance?
Paul
RE: Runout Tolerance always less than Dimension Tolerance?
Dave D.
www.qmsi.ca
RE: Runout Tolerance always less than Dimension Tolerance?
In this case it is hard to tell without seeing how the datums are utilized, but I highly doubt that the runout will be that great with the size tolerance held that close.
RE: Runout Tolerance always less than Dimension Tolerance?
Wrong
Paul
RE: Runout Tolerance always less than Dimension Tolerance?
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
RE: Runout Tolerance always less than Dimension Tolerance?
RE: Runout Tolerance always less than Dimension Tolerance?
RE: Runout Tolerance always less than Dimension Tolerance?
Position RFS, Runout, Total Runout, Concentricity-pre 94, and Conentricity-post 94 (that is evenly non-uniform) all disregard size while constraining orientation and location.
Paul
RE: Runout Tolerance always less than Dimension Tolerance?
RE: Runout Tolerance always less than Dimension Tolerance?
RE: Runout Tolerance always less than Dimension Tolerance?
In the case of bearing journals being controlled for orientation to one another as is suggested in 6.7.1.3.4, I prefer using Position at MMC. Dave will probably fall off his chair hearing me say that in this case an attribute gage is the best solution.
As in figure 51 you would constrain -C- to [pos|0(M)|C-D(M)] and -D- likewise [pos|0(M)|C-D(M)]. The reason is that making the total runout measurements for the journal is frought with problems... typically very small tolerances, traditionally large repeatibility and reproducibility errors in the measurement and typically very good processing that grinds both journals either simultaneously or in the same setup.
If someone were to make such a gage it would probably collect dust because the journals would always fit given sizes targeted away from MMC. If a little slip-fit allowance is needed to accept MMC conditions... that amount can be specified rather than zero... but ... I caution designers not to do that but rather apply the additional allowance to size (assuming that size is controlled statistically) because some stupid quality guy is going to use that tiny allowance as the position tolerance RFS! Therefore I have recommended this same type of control on most of the transmission component journals at my former employer.
Paul
RE: Runout Tolerance always less than Dimension Tolerance?
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
RE: Runout Tolerance always less than Dimension Tolerance?
Variables data capability can actually be done on it but very few would know how to approach it analytically.
Sorry if my response was offensive.
Paul