topic Joint axes are wrong when using Y-axis up setting in Fusion Support Forum

Joint axes are wrong when using Y-axis up setting

hoegge — Fri, 10 Jan 2020 14:01:34 GMT

When you use the Y-up setting the axis settings in joints are wrong. They behave as you are still using Z-up. Seems like the joint tools do not know about and correct for this setting.

Re: Joint axes are wrong when using Y-axis up setting

jeff_strater — Fri, 10 Jan 2020 14:56:39 GMT

Joint axes/coordinate system have no relation to either component or global axes/coordinate system. They are purely local coordinate systems that depends on the geometry selected for the joint origins. If you pick a planar face, the joint origin coordinate system will be set with its Z axis along that plane's normal.

Re: Joint axes are wrong when using Y-axis up setting

hoegge — Fri, 10 Jan 2020 15:25:15 GMT

So they are the imaginary "axes" of the target component face "disc" you select. Makes sense (of course 🙂 ), since this coordinate system is rarely aligned with the global coordinate system). The "joint" coordinate system does not, though, respect the Y-up setting and always have Z-up then. Might be smart to annotate the blue arrows with X, Y and Z.

Thanks for quick answer @jeff_strater

Re: Joint axes are wrong when using Y-axis up setting

jeff_strater — Fri, 10 Jan 2020 23:47:04 GMT

@hoegge - you are correct, and you raise a good point. Calling these things X, Y, and Z is misleading. I've wondered for a while whether we should change these to U, V, W or something...

Re: Joint axes are wrong when using Y-axis up setting

hoegge — Tue, 21 Jan 2020 08:44:55 GMT

@jeff_strater Yes - that would make a lot of sense, or i, j, k (also often used in geometry) - and important - add then to the 3 shown local axis lines on the object, so you can easily see what is what