3D sketching causes other parts of sketch to change position/location, when the sketch object resolves

[rgpelkey]

I'm working off of a mostly single plane sketch that I've added some perpendicular sections to. When trying to add further parts to the perpendicular portion, parts of the original sketch either rotate onto a new plane or disappear entirely. These parts are not directly connected to the new bits I'm adding and share no dimensions or are otherwise associated.

Also of note is I can only resolve these sketch objects, circles in this case, if I do not dimension them in creation; Trying to dimension the circles while creating them causes a hang for several minutes then a "Can not solve" error.

Making the circles on a separate sketch does not encounter this issue, but I consider that a workaround rather than proper or desirable behavior.

Sketch before adding circles:

After adding the circle object

The parts that disappear are part of an offset path where the original path had fillets added at the corners.

[g-andresen]

Hi,

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@rgpelkey wrote:

Making the circles on a separate sketch does not encounter this issue, but I consider that a workaround rather than proper or desirable behavior.

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1. This is not a workaround but the standard method.

    In principle, sketches should be made on separate planes
2. If you show on a real object what is to be created in the end, one could give better hints.

günther

[TheCADWhisperer]

I recommend that you fully define all of your geometry for robust and predictable results.

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

[rgpelkey]

The first sketch is the one I was working on, the second sketch is the one I had to make in order to place a few circles onto points that were already on the first sketch but kept causing issues elsewhere in the sketch.

[TheCADWhisperer]

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@rgpelkey wrote:

The first sketch is the one I was working on...

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First thing I notice is that your sketches are not fully defined - so I will have to start over from scratch.

It might be a while...

[TheCADWhisperer]

Second thing I notice is a lot of repetitive geometry that would be more efficiently created as feature patterns rather than as sketch patterns...

[TheCADWhisperer]

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@rgpelkey wrote:

The first sketch ...

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My restart is with Symmetry about the Origin (see Attached).

Not that the sketch is fully defined.  No blue lines, no white dots.

[TheCADWhisperer]

Keep sketches simple (and fully defined).

[TheCADWhisperer · Accepted solution]

See Attached.

I'll let you finish it up.

Whenever possible and practical - create sketches ONLY on the origin planes, not on faces.

[TheCADWhisperer]

I wasn't sure where you were going with this since you did not also attach the failed state part.

You might also notice that I added a bit of clearance for the lid "lip" as we cannot manufacture perfect parts in the real world.  (You can add the Chamfers and Fillets.)

[rgpelkey]

I appreciate the effort and I'll look into applying what you've said. I still think the behavior noted in my original post is unexpected and shouldn't occur, but I'll accept avoiding it as an answer for the time being, and hope that 3D sketching becomes more refined over time.

[TheCADWhisperer]

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@rgpelkey wrote:

I still think the behavior noted in my original post is unexpected and shouldn't occur...

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Attach the file in the failed state.