What's making this geometry overconstraind?

[karl]

In the attached file (and this screencast), I'd like to move the four holes and two cutouts (for a fan) .3" left to prevent the crash near the upper-right hole.  When I try to add a dimension between the left edge of the sketch and the center of the hole/cutout geometry, Fusion tells me the geometry is overconstrained.  I've tried fixing/unfixing the center point, but to no avail.  I can't see what else would be preventing this dimension.  Thanks for any tips.

[billbedford]

There is a locked sketch point at the centre of that square. 

[TheCADWhisperer]

I would significantly simplify this design, starting by breaking this up into at least 2 sketches, probably 3, maybe 4 sketches.

Use sketch points for hole locations and then place Hole Features.

[karl]

> There is a locked sketch point at the centre of that square. 

I gather that the way to unlock a point is to delete the coincident constraint.  When I do this, though, I'm still unable to add a dimension to the left edge of the sketch, even if I delete the constrains five times.  In any event, I want those points to be coincident so all the geometry moves together.  Is there another way to unlock the point?

[karl]

> I would significantly simplify this design, starting by breaking this up into at least 2 sketches, probably 3, maybe 4 sketches.

I'm happy to do that, but what's the advantage?  I'm still a newb, but when I was first starting out with Fusion I was criticized for breaking my designs into too many sketches.  What's the rule (or rule of thumb) for deciding when to "Finish Sketch?"

Also, how do I break up an existing sketch into multiple sketches?

> Use sketch points for hole locations and then place Hole Features.

I won't be extruding this sketch (except to get a sketch free of construction lines from which to make a DXF).  What's the advantage of using Hole Features over circles?

[TheCADWhisperer]

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@karl wrote:

...when I was first starting out with Fusion I was criticized for breaking my designs into too many sketches. 

I won't be extruding this sketch (except to get a sketch free of construction lines from which to make a DXF).  What's the advantage of using Hole Features over circles?

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Do you have a link to that reference?

OK, in that case I would probably create the solid body (any thickness).

Project the face into a new sketch and Save as dxf the projected sketch...

[TheCADWhisperer]

BTW - I saw several other "errors" in you sketch.

[karl]

> Do you have a link to that reference?

If you mean the criticism I mentioned, unfortunately it's buried in my post history.  It made sense at the time as my timeline was very long, so I thought a shorter timeline would be cleaner.  Maybe I'm overdoing it.  I've noticed that some operations (e.g. dimensioning) take several seconds to complete.  Would these speed up if I used more sketches?  I can imagine the calculations only being performed from the previous sketch instead of from the start of the timeline, which would make things faster, but, of course, that's just a guess as I have no idea what's going on under the hood.

> OK, in that case I would probably create the solid body (any thickness).  Project the face into a new sketch and Save as dxf the projected sketch...

Which is what I'm doing, so I guess I can skip Hole Features?

[karl]

> BTW - I saw several other "errors" in you sketch.

Please share.  You won't hurt my feelings.  😉  I'm here to learn.

[TheCADWhisperer]

Examine the Attached example.

I keep each sketch relatively simple and easy to edit.

Another difference that I might make is to use a single datum (generally the Origin) for most if not all positioning dimensions.

[TheCADWhisperer]

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@karl wrote:

> BTW - I saw several other "errors" in you sketch.

Please share.  You won't hurt my feelings.  😉  I'm here to learn.

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Missing Tangents on your slotted arcs.  In fact, if you use the sketch Slot command to create these - Fusion will do this for you.

[karl]

Aah, thanks for pointing out that tool.  That'll save a ton of time in the future.

[karl]

> Examine the Attached example...

Got it.  How'd you convert my single sketch into multiple sketches?

[TheCADWhisperer]

I never trust someone else’s work- I started over from scratch.

[karl]

Oh, jeez.  I'm embarrassed you invested the time, however short it might have been.  Thanks so much.  Still, is there a way to split up an existing sketch into multiple sketches, just in case someone didn't want to recreate everything (asking for a friend)?

[etfrench]

There is no need to use a point there.  All of the circles or arcs have center points which can be used in the same manner as a single point.

I can't see any reason to make this into multiple sketches.  It just has a lot of holes and a couple of cutouts. Turning off the visibility of constraints and dimensions will make it less cluttered and show that it really isn't that complex.  There are quite a few extraneous construction lines which could be removed.  Note: Construction line end points will need to be dimensioned in order to fully dimension the sketch.

@jeff_strater: I can find no horizontal dimension or constraint for that geometry, so I would suspect file corruption or bug.

[karl]

> Turning off the visibility of constraints and dimensions

How do you do that?

[karl]

> There is no need to use a point there. 

Where?  I don’t know what you’re referring to, I’m afraid.

[TheCADWhisperer · Accepted solution]

[etfrench]

I missed the locked point 😣 I'll change my assertion of a bug on a horizontal constraint to a UI bug on only exposing properties of geometry with color, especially on points.  One should be able to see the properties like X,Y, Z position, Fixed/Unfixed, constraints, etc. in a dialog.