[To...] Posted August 30, 2019 Share Posted August 30, 2019 I know I've posted an application similar to this in the past but I think it was on the old forum. Take a look at the sketch below and offer any suggestions as to a methodology for measure surface profile of a cone to AB. No Free Form Surfaces. For clarity, let's assume B is facing in the + Z direction. Link to comment Share on other sites More sharing options...
[De...] Posted August 30, 2019 Share Posted August 30, 2019 Perhaps I am missing something. Why not just use a profile characteristic with the feature a cone and with A and B in the datum reference frame? Link to comment Share on other sites More sharing options...
[Br...] Posted August 30, 2019 Share Posted August 30, 2019 Datum B only controls the location of the diameter. You could just do a secondary alignment where -A- will be input for spacial rotation Z+, and origins of X and Y. Then use the cone for the Z origin. Use this secondary alignment for the DRF of the Cone profile to |A|B|. Now you need to create another secondary alignment for the diameter. Same as before, -A- as spacial rotation, origin X &Y. But this time use -B- to control the Z origin. Now create a circle on a cone feature that references this new AB alignment instead of the base alignment. Make sure to set the distance in -Z- for the circle location to 18.(Don't just type it in, you need to click the icon next to the diameter to do this properly.) Now output a diameter characteristic for the Ø24±0.2 requirement using the circle on a Cone. Do you actually have a drawing that requires this? I've never seen anyone actually do this on a real drawing. The closest I've seen is where they accidentally forgot to make the diameter basic. Link to comment Share on other sites More sharing options...
[Br...] Posted August 30, 2019 Share Posted August 30, 2019 Please sign in to view this quote. Notice the Ø24±0.2 isn't basic and has an actual tolerance. This is this a weird thing found in the Y14.5 standard that almost nobody uses. The purpose is to control the taper angle tighter than the size. Link to comment Share on other sites More sharing options...
[Cl...] Posted August 30, 2019 Share Posted August 30, 2019 I think this is fairly simple. (what I would do) If -A- is a long enough cylinder, I'd use it for spatial rotation & XY zero. Use -B- for Z zero. Scan the cone using the helix option over the full length of the cone, pull A & B into the characteristics datum drop-downs. Link to comment Share on other sites More sharing options...
[De...] Posted August 30, 2019 Share Posted August 30, 2019 Well I figured I must have been missing something and I was. That explains it. My first thought would be to first measure the cone based on the nominals for the cone. Then measure the diameter using a cone calculation (or alternatively a bunch of intersections of a plane at the correct height and a 2d line patterned around the cone recalled into a circle) - you can then use the measured diameter as the basis for a cone that is defined using formulas and recalls the points from the original cone. Now you can use a profile characteristic and Datums A and B because the derivative cone defined with formulas is fully defined once the original cone is measured. Link to comment Share on other sites More sharing options...
[To...] Posted August 30, 2019 Author Share Posted August 30, 2019 Please sign in to view this quote. Because without using a FFS, Calypso requires you to populate a tertiary datum with a feature and I don't subscribe to populating the DRF with features "just to get an answer." Link to comment Share on other sites More sharing options...
[To...] Posted August 30, 2019 Author Share Posted August 30, 2019 Please sign in to view this quote. See my reply to Derek Link to comment Share on other sites More sharing options...
[To...] Posted August 30, 2019 Author Share Posted August 30, 2019 Please sign in to view this quote. I didn't put 2 & 2 together on the toleranced diameter. I was strictly thinking profile only. Good catch. You're pretty much seeing this in the same manner it was presented to me by the customer with one exception, as follows: Our customer dimensioned a print using the clip out of a GD&T standard as shown below. To do this, I would like to be able to first measure the diameter of the part at the basic 18 dimension and then tell Calypso this is the nominal diameter to measure the profile against. Please sign in to view this quote. Why not a cone calculation? Link to comment Share on other sites More sharing options...
[Br...] Posted August 30, 2019 Share Posted August 30, 2019 Please sign in to view this quote. You could. The only difference would be that it will keep the measured circle oriented normal to the Cone axis instead of the Alignment. You also have more control over the evaluation methods I believe if you measure it at that location. Link to comment Share on other sites More sharing options...
[Me...] Posted August 30, 2019 Share Posted August 30, 2019 I agree with Derek. The only thing I think I would do different is create a new cone from the measured diameter data and measure that, as opposed to recalling points to avoid any probing error from the original cone measurement. Link to comment Share on other sites More sharing options...
[Br...] Posted August 30, 2019 Share Posted August 30, 2019 Please sign in to view this quote. I'm not sure I quite understand this. Isn't that already the "Nominal Diameter" at that location? I sounds like you just want to treat that as a basic dimension for the profile tolerance.(This would be the normal way to do profile on a conical feature.) I would just use that second alignment I talked about earlier that includes A and B. You can still do the ISO 5459 constraints in secondary alignments with minimal effort if this is a concern. Link to comment Share on other sites More sharing options...
[An...] Posted September 2, 2019 Share Posted September 2, 2019 Remove the datum or alter the values. See attached.Contribution_02_09_2019_a.pdf Link to comment Share on other sites More sharing options...
[To...] Posted September 3, 2019 Author Share Posted September 3, 2019 Please sign in to view this quote. In ASME Y14.5-2009, this drawing is legal. Following is the excerpt from the standard. 8.4.2 Conicity A profile tolerance may be specified to control the conicity of a surface in two ways: as an independent control of form as in Fig. 8-17, or as combinations of size, form, orientation, and location, as in Fig. 8-18. Figure 8-17 depicts a conical feature controlled by a profile of a surface tolerance where conicity of the surface is a refinement of size. In Fig. 8-18, the same control is applied but is oriented to a datum axis. In each case, the feature must be within size limits. See attached with both figures and interpretations.Profile of Cone with toleranced diameter.pdf Link to comment Share on other sites More sharing options...
[To...] Posted September 3, 2019 Author Share Posted September 3, 2019 Please sign in to view this quote. I agree with your interpretation. As far as it being the normal way, it seems that if there was a specific topic in the standard on this topic, it must be more common than we think. 😃 Link to comment Share on other sites More sharing options...
[Br...] Posted September 3, 2019 Share Posted September 3, 2019 Please sign in to view this quote. Oh I have no doubt there are some specific applications where this might be useful. The new 2018 revision of the standard actually dropped this example in favor of the new Dynamic Profile modifier which effectively does the exact same thing as the example found in the 2009 revision. Link to comment Share on other sites More sharing options...
[Aa...] Posted September 3, 2019 Share Posted September 3, 2019 Please sign in to view this quote. Or at least important in the mind of someone on the Y14.5 subcommittee. 🤬 Link to comment Share on other sites More sharing options...
[An...] Posted September 4, 2019 Share Posted September 4, 2019 _____ Link to comment Share on other sites More sharing options...
[To...] Posted September 4, 2019 Author Share Posted September 4, 2019 Please sign in to view this quote. Brett, Secondary alignment not able to compute with CylinderA as Spatial and X/Y Origin and the cone as the Z. Link to comment Share on other sites More sharing options...
[Br...] Posted September 4, 2019 Share Posted September 4, 2019 Please sign in to view this quote. You're right...Dang. So the only way around this is to do a bunch of 3D curves on the cone. Your Secondary alignment will be CylinderA as Spatial and X/Y Origin. Then do a best fit of curves alignment using the 3D curves you just measured. Make sure the alignment referenced is the one you created with CylinderA, and only best fit along the Z translation direction. (I've actually done this before so It should work.) Link to comment Share on other sites More sharing options...
[Aa...] Posted September 4, 2019 Share Posted September 4, 2019 Could you not use a cone calculation (intersection) to establish Z in your secondary alignment? Link to comment Share on other sites More sharing options...
[To...] Posted September 4, 2019 Author Share Posted September 4, 2019 Well, well, well. Guess what. The customer DID have Free Form Surfaces. So, we scanned the cone. Recalled the points into a FFS. Created a surface profile to A only. This allowed data to translate along the Z axis, which evaluated profile relative to the actual diameter at the gauge line, which is what the customer wanted to do. Not sure if their customer will buy into this method but it may be good enough for now.... 😃 😃 😃 Link to comment Share on other sites More sharing options...
[To...] Posted September 4, 2019 Author Share Posted September 4, 2019 Please sign in to view this quote. Funny, that's what I was trying figure out when I realized the other solution. Link to comment Share on other sites More sharing options...
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