Recently I was working on an animation in which I had to use an angle mate. The angle dimension varied with time in the animation.

Up till then I had thought my problems with angle mates was because I hadn’t bothered to read up on them properly. Have been using SW since 1996 and found angle mates iffy back then, so never bothered with them much. Well, a quick search here quickly informed me that I was not being completely stupid and that SW (to put it nicely) is somewhat less than diligent on correcting these problems.

Yes I was having the problem of the angle randomly flipping and this stood to ruin the animation concept I was working on. My sense of humour failure was quite abject. So I came up with this work around which seems to be stable.

Basically I drove the angle in a sketch with a distance mate using an equation. Working on the theory that 2D sketch angles are reasonably stable and you can’t directly make simulations change part dimension values.

See attached assembly (all its parts are internal)