pylfrm, that is what I was looking for. Thank you for the ASME Y14.5-2009 reference. I think I can do this with some creative formating. I suppose that if I have a situation where one angle between two features is different, like say a clock with a missing "12", I could dimension the angle...
dgallup, I agree that [3.42857] is close enough. I was getting hung up on the "Basic = theoretically perfect" definition. I guess what I was really searching for was whether there was an accepted standard way of handling the issue. It sure seems like it would have come up before.
CheckerHater, I understand that Basic dimensions are not subject to cumulative effect, but the expression "3.429 DEG" is an *approximation* of the theoretically perfect dimension. How does the reader know that the theoretically perfect value of 3.428571 (with the decimal part repeating ad...
I am wondering how best to specify a basic angle when it is a repeating decimal. I don't want the cumulative effect to be out of tolerance and the number of repeats is significant. In this case, the angle is 360 deg / 105 and there are 103 repetitions. It's a series of features repeated almost...
pmarc,
Yes, of course you are correct. The fact of the basic dimension also applying to the tighter surface profile tolerance slipped by me. As an alternative to your 'BASIC 34.29 DOES NOT APPLY' idea, would the use of a customized reference frame that shows only rotational constraints in the...
No, dgallup, symmetry controls the location of the mid-plane between the opposing surfaces, not the surfaces themselves. Borrowing pmarc's illustration using "4 flats nominally perpendicular to each other" from the posting of 30 Dec 16 16:30, "Picture an as-produced part that has each pair of...
Thanks for all your input. Pmarc, if I understand your post of 29 Dec 16 20:27 correctly, either of the two illustrations shown attached would work and be equivalent to each other?
Regarding the comments on customized datum reference frames: I was not familiar with the concept, so I studied up...
Thanks for your reply. However, it is my understanding that the composite profile callout as you describe would constrain the variation within the pattern to the tighter tolerance but allow the entire pattern to move within the larger tolerance. This isn't what I am looking for. I want the...
I am wondering how best to dimension a part with the following characteristics. It is shaped like a short shaft with a bore down its length and a series of rectangular keyways cut full length into it. The keyways are equally spaced, so it is essentially a splined shaft with rectangular grooves...
If I may regress temporarily, Mike Halloran is right, the motorcycle is a 7-cylinder. A line splitting one cylinder in half and extending through the shaft center leaves 3-1/2 cylinders within 180 degrees; 3-1/2 x 2 = 7.
The neatest radial that I have seen was a comparatively minute...
