topic Sketch Dimension Flipping Sides in Fusion Design, Validate & Document Forum

Sketch Dimension Flipping Sides

tookemtoni — Mon, 29 Nov 2021 16:38:31 GMT

Hi, I am using this feature for part name engraving on all of my components but the constrained text block keeps shifting. I normally just correct it but it keeps on happenings since the design dimension are changing for each assembly. How can I better constrain this text block? f3d file attached.

Re: Sketch Dimension Flipping Sides

jeff_strater — Mon, 29 Nov 2021 21:29:54 GMT

I'm looking at this. Thanks for sharing the model. Most likely this is a solver bug, but I have not yet untangled all the parameters.

[edit] certainly seems to be a sketch flipping bug - created FUS-95004 to track it. Thanks for sharing the model.

Re: Sketch Dimension Flipping Sides

tookemtoni — Fri, 03 Dec 2021 05:47:32 GMT

Great thanks and you are welcome. 😎 In the meanwhile I did this and it is working so far. See attached photo

Re: Sketch Dimension Flipping Sides

jonrbloom — Fri, 03 Dec 2021 16:10:04 GMT

This is the one remaining area of sketches that is still a mystery to me. How does Fusion determine the 'correct' direction for such dimensions? Technically, such a sketch is not fully constrained, because there are two solutions - And that's not a criticism of this specific sketch. If you attempted to add another dimension to fix the right hand side of the text to the back of the model, Fusion would likely complain that it's over constrained.

What's especially frustrating is that to FIX these kinds of inversions (where one day the sketch suddenly decides to flip for no obvious reason), you have to start dismantling the constraints/dimensions (which may be complex formulas), so that you drag the geometry back to the correct side, and then reassemble the constraint's.

It feels like there is a bit of cheating going on behinds the scenes for Fusion to be able to 'choose' the correct solution to such sketches following a recompute 🙂 Is there really no way to make this less fragile (e.g. signed dimensions, or a new constraint type to define the direction/side)?