Degrees of freedom for a Cone

[[Ti...]]

A cone removes 5 deg of freedom. As you see below, if you imagine the geometric counterpart of a cone as your fixture, the moment you place the cone in the fixture, the only thing you can do is spin the cone.

GOM is not setting the up and down translation to the vertex point of the cone. This isn't a real problem, but I wanted to ask why this is?

 

[[Ch...]]

Please have an look to the screenshot of the datum system dialog

 

As you can see, if you enable the PT modifier then the apex will be used to restrict the translation.

And yes, the default for this modifier is off. Our expierences is that most of the used cones are cones with a small opening angles (say something below 5 degrees) causing from draft angles during injection molding processes. For such cones the usage of the apex point would be unexpected. Therefore we decide to set the default to off, and indicate it on the auto name

Of course in your example the opposite heuristic would be the correct one, but as I said most cones have only a small opening angle.

Hopefully I understood your question correctly and my short answer helps you.

Best regards
Christoph Schult.

[[Ti...]]

Makes sense. Thanks for the explanation.