[Ma...] Posted February 3, 2022 Share Posted February 3, 2022 Hello, i just want to know if we are understand this correctly. Here on picture is forged part, where can vary thickness and mismatch of upper and lower shape. Can i ignore central axis of part and just report deviations of each surface? Aka cylindricality and flattness? Surf. profile is for all not tolerated dimensions. Link to comment Share on other sites More sharing options...
[Da...] Posted February 3, 2022 Share Posted February 3, 2022 Please sign in to view this quote. Martin, first I would like you to confirm, is there also a note on the drawing similar to "Missing basic dimensions to be taken from CAD model"? Is the drawing to ISO? Link to comment Share on other sites More sharing options...
[Ma...] Posted February 3, 2022 Author Share Posted February 3, 2022 Yes i forgot - ISO In final drawing will surelly be from CAD model. This is just porposal drawing. Link to comment Share on other sites More sharing options...
[Da...] Posted February 3, 2022 Share Posted February 3, 2022 Please sign in to view this quote. For cylinders I'm sure that cylindricity isn't going to be enough. You need surface profile for those, as it would also control diameter that way. For planes, if they aren't feature of size, flatness is enough. Link to comment Share on other sites More sharing options...
[Ma...] Posted February 3, 2022 Author Share Posted February 3, 2022 Please sign in to view this quote. Actually i will report profiles. I am just curious if i can report one half of cylinder to itself, or i have to take axis into account. Like make one CZ cylinder as base A Link to comment Share on other sites More sharing options...
[Ke...] Posted April 20, 2022 Share Posted April 20, 2022 Dane, For what it's worth, I work in a machine shop where our stock comes from forgings made in house. We use similar call outs for the entire forging, and in that case we would pick up the top and bottom together as 1 cylinder, then report the profile of the entire thing. Being that the profile has NDRF, it is really controlling form only. I believe the call out is trying to control the form of the entire cylinder, including any mismatch that may be present. That's my 2 cents and how I would handle it. Regards, Keith Tate Link to comment Share on other sites More sharing options...
[Ri...] Posted May 23, 2022 Share Posted May 23, 2022 Per your drawing, Datum R is a single cylinder at one end only. The other end is interrupted by separate features, the datum would have to state both cylinders as one or have a second Datum designation which would or could become a Common Datum (Ex: Datum R and other end as Datum S could become Datum R-S). Link to comment Share on other sites More sharing options...
[Ma...] Posted May 23, 2022 Author Share Posted May 23, 2022 Please sign in to view this quote. Sorry for mystifying, but that is not datum R - it's just dimension for Radius but without number. Link to comment Share on other sites More sharing options...
[Da...] Posted May 26, 2022 Share Posted May 26, 2022 You need to report the profile of all the surfaces simultaneously. You can't just report the form - additionally, the profile also controls the size, which form won't include. This is effectively creating a best fit datum reference frame that all the profile elements must conform to. The best way to show compliance is probably to measure points on all the features of interest as a single freeform object, then report profile to no datums of the single freeform. That will give you the best optimization. You could also create a best fit DRF, and then report the profile of all the features back to that. You risk rejecting good parts though. Link to comment Share on other sites More sharing options...
[To...] Posted May 26, 2022 Share Posted May 26, 2022 Please sign in to view this quote. It is also controlling size. Link to comment Share on other sites More sharing options...
[Ri...] Posted May 26, 2022 Share Posted May 26, 2022 Please sign in to view this quote. Only if there is not a refinement of size somewhere else on the drawing. Link to comment Share on other sites More sharing options...
[Ma...] Posted May 27, 2022 Author Share Posted May 27, 2022 Image that I attached is whole drawing - all dimensions are basic, so there is diameter for one(?) cylinder on sides, radius for partial cylinder in middle, some distance lengths and angle. From this thread I got this. If there is cylinder with diameter, then i take whole cylinder ( not just part on half of part - area stricted to gridlines ) - same for length - oposing faces. I would agree, that they could determine some bases to be clear with it. Normally u use profile for just face where arrow points to. Link to comment Share on other sites More sharing options...
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