topic Help with open loop, cant find problem with "check sketch" in Fusion Design, Validate & Document Forum

Help with open loop, cant find problem with "check sketch"

Cave_Master — Wed, 29 Nov 2017 20:50:01 GMT

I usually use AutoCAD for similar sketch features but decided to give Fusion a try for this because I know it could save me a lot of time.

Anyway I have completed my sketch, used "check sketch" feature to locate any errors in the loop. I closed all the openings with trim and/or extend.

Now the check sketch says there are no open loops, however I can't extrude and the sketch behaves as if it is open still.

Also, unfortunately not in the screencast but maybe a clue - the offset feature is treating the loop like one continuous loop.

Re: Help with open loop, cant find problem with "check sketch"

davebYYPCU — Wed, 29 Nov 2017 20:58:20 GMT

2 things to check for,

Return to the sketch in Edit mode,

1. Is Show Profile ticked in the sketch pallete?

2. With all the sketch items selected, right click, is there a menu item Move to Sketch Plane,

if so click that.

Might help....

Re: Help with open loop, cant find problem with "check sketch"

jeff_strater — Wed, 29 Nov 2017 21:45:06 GMT

Also, use this technique: find-leak-in-sketch-geometry, which can reveal where the problem might be.

Re: Help with open loop, cant find problem with "check sketch"

jasonhomrighaus — Wed, 29 Nov 2017 22:03:21 GMT

Can you attach your model?

Re: Help with open loop, cant find problem with "check sketch"

Cave_Master — Wed, 29 Nov 2017 22:40:45 GMT

Sketch profile is turned on in sketch pallet.

I used the Hughes tooling leak detection method described in that other thread. I dont get consistent results with it and it causes erratic sketch behavior (when clicking a line it inverts the elliptical section of the curve. You can see this when I zoom out.

Unfortunately I can't attach the model. Normally I am OK with uploading models, but this one contains some proprietary geometry.

Re: Help with open loop, cant find problem with "check sketch"

jeff_strater — Wed, 29 Nov 2017 23:18:53 GMT

A couple of things: First, can you click on the warning you get here:

I'd like to know what that says, although I suspect I have an idea.

This definitely looks like a Fusion bug, and it seems to be around that top line:

Also, I noticed at several points in the video that there appear to be construction curves nearly coincident with the top and bottom curves:

I'm not certain that this is related to the problem, but it might be.

I'm also suspicious since you mention elliptical curves, and especially so when you show the inversion that happens. This seems bad.

But, to further diagnose, we'd have to see the design. You can either share it with me privately, via PM, or you can trim down the design. Does this sketch contain proprietary information as well? Because you can roll back the timeline to just after the sketch, and right click, and choose "delete all features after marker", so that the design contained only this sketch, and share it.

Jeff

Re: Help with open loop, cant find problem with "check sketch"

Cave_Master — Wed, 29 Nov 2017 23:54:25 GMT

OK, I will click the warnings and see what they are.

The construction curves are coincident. They were the original lines for the design, this design is 2mm wider than the original. Everything in the timeline is dependent on this sketch. I went backwards to modify the sketch and everything downstream.

I can share the design privately, I just dont want to post it in a public place. I will PM you a copy

Thanks

Re: Help with open loop, cant find problem with "check sketch"

lichtzeichenanlage — Thu, 30 Nov 2017 06:45:31 GMT

Perhaps the script can't handle the overlapping construction lines?

Re: Help with open loop, cant find problem with "check sketch"

jasonhomrighaus — Thu, 30 Nov 2017 16:16:54 GMT

If you would like to send me a copy I would be glad to look at it for you.