[Am...] Posted March 3, 2021 Share Posted March 3, 2021 Hi guys, I have a couple things I wanted to run by everyone for some clarification on this part. I have an ID with a 1° taper the only tolerance on this is the Profile callout of .005. I have a basic 1° for the angle and a Basic .280 at .630 from Datum A. I found almost an identical problem in my GD&T textbook the difference there is my Datums are backwards but also they have a tolerance on the diameter. Im looking at this program and the profile characteristic is giving the outwards to infinity result, I think this should just be a bilateral-single result. When I change that this profile is out at .006-.007". This is going to be a big deal and I want to make sure I'm doing this right. -In the textbook because the diameter has a tolerance the profile is not checking the size of the cone and the tolerance zone size of may change as long as its the same gap. On my part the size is Basic and thus being controlled by this profile only. Is this correct? -My zone is two coaxial cones at 1°, one of size .275" and the other .285" right? How does this change based on the change in angle since nothing is toleranced and controlled by this profile how much freedom do I have on this cone? -Im scanning the cone feature vertically due to the profile view dependency rule. -My actual angle is coming in at 0.85° and im measuring that bottom opening with a caliper at about .288" (sanity check). When I measure with the zeiss im not going to the bottom due to the fixturing of the part im scanning my cone above that. -My profile characteristic is Primary A, Secondary B, Tertiary A. I cant use a Geometry best fit to adjust my constraints because for whatever reason Calypso does not allow Cones in that. So any advice you guys can provide me, this is going to ruin my day and these parts have a month long cure that has gone to waste now. Link to comment Share on other sites More sharing options...
[Cl...] Posted March 3, 2021 Share Posted March 3, 2021 If my math is correct the intersected/shelled diameter at the other end should be .301994, just a s a sanity check. Link to comment Share on other sites More sharing options...
[Ro...] Posted March 3, 2021 Share Posted March 3, 2021 -A- is constraining 4 DOF, -B- is constraining 1. The only free DOF is rotation around the cone axis, which essentially does nothing, as the tolerance zone doesn't change and there's no best fit. You are correct. It's a .005 bilateral tolerance zone leveled and positioned to -A- and centered to -B-. Link to comment Share on other sites More sharing options...
[Er...] Posted March 3, 2021 Share Posted March 3, 2021 So profile is a monster to report when out. We use space points to communicate what is out and where. Profile is going to control both form and position in that callout. Along with "roundness" and "straightness" if you get what I mean. If it were me... Under Resources-Characteristic settings editor-Printout. try turning on additional position result, axis endpoints, and extended profile output. Add a true position call out. With the axis endpoints on it should say what end is where. Add a Form callout so they know if it's the position only, or just the form. And while I was at it I would add perpendicularity. And I would use CAD evaluation to communicate what was out and where. MEGO often happens when just numbers are used. Graphics are the best way to communicate. Good luck. Link to comment Share on other sites More sharing options...
[An...] Posted March 4, 2021 Share Posted March 4, 2021 _ Link to comment Share on other sites More sharing options...
[Jo...] Posted March 4, 2021 Share Posted March 4, 2021 Please sign in to view this quote. I'm curious about the design intent. .005" profile is not very good at controlling perpendicularity, angle, or form. It is also terrible for controlling a diameter. This is an inch drawing ? A gage diameter would vary greatly within that bilateral zone. If my calculation is right, your angle could be off .45 degrees per side and still be in tolerance along that length if location and perpendicularity were correct. Link to comment Share on other sites More sharing options...
[Am...] Posted March 4, 2021 Author Share Posted March 4, 2021 Please sign in to view this quote. This is kind of what is confusing me here, in this scenario how can the actual diameter be at .272 and the profile be well within tolerance at .0026? The main reason I posted this is to see if I understood the tolerance zone created by this callout and I feel like if angle and center is perfect the part should still not be able to be .008" from the basic .280. Can you explain this to me? Link to comment Share on other sites More sharing options...
[Ro...] Posted March 4, 2021 Share Posted March 4, 2021 This is based on your picture. There is a chamfer at the bottom of the cone in your photo which I don't know the size of. The basic is coming from that, so I just used .630 for the diameter sizes. In other words, if you do a sanity check and the .280 comes from the intersection of the cone and the .630, you need to compensate for the chamfer on the diameter check. Link to comment Share on other sites More sharing options...
[Am...] Posted March 4, 2021 Author Share Posted March 4, 2021 The chamfer is .035 I believe, I think right above the chamfer its supposed to be around .281 if I remember the calculation I did. Link to comment Share on other sites More sharing options...
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