3D Sketch behaving strangely

[laurent.vidonne]

Hi folks,

I'm working on a design where I use a 3D Sketch to model the end of a 'fork'.

In the screenshots below, after I've done quite a lot of work in the sketch, you can see that it's fully defined (lock icon on Sketch8 in the browser) :

So far, so good. Now, I need to set two points as the basis for further items. I place these points on 2 segments, and set them in place by defining their distance to some segments. The 1st one goes OK (blue mark), the sketch is not fully defined yet, as the distance for the 2nd (red mark) is not yet set :

This is when things go badly wrong : as I set the distance from the 2nd point to a segment, most of the sketch turns blue, as though most of the constraints had suddenly disappeared. I repeat for clarity : the only change I make from the image above to the one below is setting a distance for a not-yet-fully-defined point :

Does this make any sense ?

This is the second time I build this 3D sketch : the 1st one went OK, but I needed to change a dimension, and Fusion 360 simply refused to do it, claiming it was unable to compute the change. I'm now trying to rebuild another sketch to work around this, and I stumble on another roadblock....

Thank you for your help.

[jhackney1972]

Please post your model so the forum users can take a look and try and troubleshoot your issue.

[laughingcreek]

There are still kinks to be worked out of the 3d sketching tools.  This is one of them.  It's possible that the AD team will want to look at your model so they have another example of this issue, so please do post it.  I'm not sure who the best person at AD is to tag on this, but maybe @jeff_strater  will come along and notify the  right group.

[davebYYPCU]

Much quicker to do that with one rectangle, Extrude the block and fillets to finish.

[laurent.vidonne]

Hello,

Thank you for taking the time to look at this.

@davebYYPCU: agreed, there is always more than one way to skin a cat, for some reasons this is the way I chose in this case, maybe not the best but... My question was about 3D sketch behavior, not the best way to do this.

@laughingcreek  and @jhackney1972 : thank you for your suggestion, I've attached a cleaned up version of the file here.

[jeff_strater · Accepted solution]

Thanks for the model.  The Fusion bug is FUS-69002

Certainly does seem to be incorrect behavior...

[laurent.vidonne]

>Thanks for the model.  The Fusion bug is FUS-69002

Noted, thank you