【转帖】olerancing problem

yang686526

tolerancing problem
i am specifying a shaft that will be made in batches of 100. my shaft is 8 mm nom diameter. i want to put a reasonable size limit on the shaft (say f7). so far so good.
the problem that arises is that although the actual diameter is relativley unimportant, the diameter of each individual shaft must be consistent along its length to within .003mm. i obviously don't wnat to put a size tolerance of .003mm and apply it to the whole batch. any suggestions?
see asme-y14.5. you can tol the size for a certain length.
chris
systems analyst, i.s.
solidworks/pdmworks 05
autocad 05
you can loosen up the diameter tolerance and control it using runout.
geoffthehammer,
   specify cylindricity.
                       jhg
you can loosen up the tolerance on the diameter to cover the full range of value and control each individual shaft by using straightness control. since straightness of the line elements of the surface refer to the parts true geometric counterpart, the vairation within each individual shaft is controlled by the tolerance you secify for the staightness.