【转帖】a quick question on total runou

yang686526

a quick question on total runout
my question is this:
if i specify a total runout of 0.05mm on an od of 6.05 +/-0.05mm, does that mean when it gets inspected by qa the maximum allowable diameter is 6.15mm or 6.1?
find a job or post a job opening
6.1
the size of the feature cannot exceed 6.1 but when the feature is at 6.1 it can run out .05 which gives it an actual mating envelope of 6.15.
powerhound, gdtp t-0419
production supervisor
inventor 2008
mastercam x2
smartcam 11.1
ssg, u.s. army
taji, iraq oif ii
total runout is always in rfs and is inspected on its actual size as long as the feature meets the size requirement. the maximum allowable size is 6.1 mm so 6.15 is nonconforming - it exceeds the size requirement.
dave d.
perfect form at mmc i suspect?
rule #1 would apply to the size of the feature but it would not apply to runout wrt whatever datum is specified.
powerhound, gdtp t-0419
production supervisor
inventor 2008
mastercam x2
smartcam 11.1
ssg, u.s. army
taji, iraq oif ii
i'm having problems getting a tube manufactured without variations in a diameter making assembly more difficult than it should be, the diameter varied depending on where you measured the part, but still within the specified tolerance band. i'm hoping total runout will make things clearer for the manufacturer and for us to inspect.
thanks for your answers, it comfirmed what i thought was the case.
so to what datum(s) are you specifying total runout? you cannot just point to the tube and specify total runout alone. it must be referenced back to a datum or datums. if the tube is one diameter along the entire length then you must create datum target points or axes and measure wrt to the same ones every time. the other option is cylindricity but that one is very difficult to check.
powerhound, gdtp t-0419
production supervisor
inventor 2008
mastercam x2
smartcam 11.1
ssg, u.s. army
taji, iraq oif ii
oh sorry, information on a need to know basis.
i've specified a straightness tolerance on the tube axis of 0.2mm diameter. the tube axis is the datum and runout is relative to that datum.
if you have a datum identifier attached to the centerline then that violates the asme standard. you need to specify whether it's the axis of the od or id but you can't call the od the datum and then specify a runout wrt the od unless you have the datum points as i referred to earlier.
powerhound, gdtp t-0419
production supervisor
inventor 2008
mastercam x2
smartcam 11.1
ssg, u.s. army
taji, iraq oif ii
i agree with powerhouse on this.  it sounds like maconmech is already applying it correctly, and that this is just a question of interpretation, which i think was well answered.
matt lorono
cad engineer/ecn analyst
silicon valley, ca