Runout
Runout
(OP)
Hi All,
Please see the attached file.
Genarally I have seen runout/total runout control is apllied for stepped shafts. where axis of one of the stepped part is considered as datum and the runout controll is applied to the other stepped part. Also I have seen some examples where compound datums are used.
Question is
1) Can we use total runout control for a simple shaft(No steps)? Please refer to the attached file, the toleranced feture itself a datum feature.
2) If it is a legal sceification , can any one suggest me how to simulate the datum.? can we use V-blocks? (If we use collects- the ASME says The entire suraface(datum feature) to be used to establish the datums then there is no space for dial indicator to measure)
Please help me to understand the standards better.
Madhusudhan
Mechanical Engineer
Please see the attached file.
Genarally I have seen runout/total runout control is apllied for stepped shafts. where axis of one of the stepped part is considered as datum and the runout controll is applied to the other stepped part. Also I have seen some examples where compound datums are used.
Question is
1) Can we use total runout control for a simple shaft(No steps)? Please refer to the attached file, the toleranced feture itself a datum feature.
2) If it is a legal sceification , can any one suggest me how to simulate the datum.? can we use V-blocks? (If we use collects- the ASME says The entire suraface(datum feature) to be used to establish the datums then there is no space for dial indicator to measure)
Please help me to understand the standards better.
Madhusudhan
Mechanical Engineer





RE: Runout
2. However I believe you could define datum targets A on both ends of the shaft (datum target areas or points) and assign runout control relative to A to the portion of the shaft in between the targets. Datum targets configurations could be somehow similar to the one shown for datum A in fig. 4-34 (Y14.5M-1994). And the portion of the shaft controlled by runout tolerances would be denoted by a chain line as shown in fig. 1-11.
RE: Runout
If you are trying to control the form of the cylinder, I would suggest that you use cylindricity. Place this feature control frame below the size tolerance and eliminate the datum.
Cylindricity has all the attributes of total runout except cylindricity is to itself. It controls straightness of the axis, roundness and straightness of the surface (size distortion) all combined.
Dave D.
www.qmsi.ca
RE: Runout
RE: Runout
A cylindricity control would reject parts that meet the diameter tolerance, but have a cross section that more out of round or tapered than is allowed by the cylindricity control. While it's not a useless control (looking at you concentricity), I find situations where the cylindricity matters more than the diameter somewhat rare.
RE: Runout
Then you can ask yourselves concentricity between what features?
BTW last active threads looks like examination for professors :)
RE: Runout
Dean
www.d3w-engineering.com
RE: Runout
I am with you, Don's tip gives us a excellent explanation. http://www.tec-ease.com/gdt-tips-view.php?q=232
SeasonLee
RE: Runout
http://tec-ease.com/gdt-tips-view.php?q=144