Sketch Mirroring. Timeline/objects. Why are there so many objects to mirror in simple sketch?

[ashydlyk]

Hi there

I'm new in Fusion 360 so maybe there is a simple way to manage my issue.

What we have: a sketch (pic.1-2-3 --1) with 200+ changes in the Timeline. Summary 20+ lines, 10+ circles, 10+ Fillets. Simple, nothing complex.

Issue: When I select Items to Mirror Fusion360 Mirroing windows shows me 1500+ objects (pic.1-2-3 --2)! And of course when I select line to mirror system hangs up or crashes.

results of Mirroring - q-ty of objects duplicated (pic.1-2-3 --3).

Test sketch made just for testing without dimensions etc with +/- same q-ty of circles/lines/fillets shows q-ty of objects = 169 (pic.4, pic.5).

Questions:

1. Why Fusion shows me so many objects to mirror?

2. Where can I manage these objects to decrese its q-ty?

3. Are there any way to copy Sketch with dimensions but without timeline to the new file/project to decrese such big q-ty of objects?

4. Are there any way to 'refresh' timeline but to keep sketch' dimensions?

thank you in advance

[jhackney1972]

Please attach your model containing the sketches.

If you do not know how to attach your Fusion 360 model follow these easy steps. Open the model in Fusion 360, select the File menu, then Export and save as a F3D or F3Z file to your hard drive. Then use the Attachments section, of a forum post, to attach it.

[davebYYPCU]

Fusion is bogging down because that sketch is excessively complicated.  

Blue, orange and white objects are not recommended.  Black purple or green way better.

if you are mirroring in the sketch, then don’t, mirror solids will help immensely.

If filleting in sketch, consider fillets in the modelling, at end of timeline.

2. Break that sketch up into several, one sketch per feature, is recommended for new people.

Outline, Extrude, (no sketch fillets)

cavities, Extrude > Cut

holes, with modelling hole tool.

fillets - modelling type, at end of timeline.

1.  Fusion courts all the articles, end points and centre points, etc.

3. Save copy as, 

4.. No idea what you mean.  Sketches have no timeline, many sketch articles will be in one timeline icon.

Post the file, could be you are even making one sketch per article, for the non shaded sketches.

Might help….

[ashydlyk]

Please check you DM for details.

[ashydlyk]

Sorry but I don't think that this sketch is excessively complicated. It consists of few simple elements that where changed (dimensions/position) many times. I see that every chang I made somehow somewhere saved in the project and when i select the sketch it selects these changes too and show them as Objects. That's why i have so many object to mirror in such simple sketch.

Please provide more info about or where i can read baout "Blue, orange and white objects are not recommended. Black purple or green way better."

If filleting in sketch, consider fillets in the modelling, at end of timeline.
This should not effect on my issue.

Fusion courts all the articles, end points and centre points, etc.
Even if to count all these there should be 200+ objects but not 1500+.

Additionaly I found next: Sketch - Mirror operation - Delete Mirroring result - Add some elements on existing sketch (2 circles were added) - Mirror - q-ty of objects will be increased (in my case from 1577 to 2910).
So something added but where? Sketch is the same but with 2 more circles in it.

No idea what you mean. Sketches have no timeline, many sketch articles will be in one timeline icon.
Then let's try to find out why Fusion calculates so many Objects. And where it is possible to check/view these objects.

[jhackney1972 · Accepted solution]

I have returned my response.

[jeff_strater · Accepted solution]

"Why Fusion shows me so many objects to mirror?"

"Why are there so many objects to mirror in simple sketch?"

This is just the nature of sketching in a parametric CAD system.  Take a "simple" rectangle:

In this rectangle, there are:

• 4 lines
• 4 points
• 2 dimensions
• 4 horizontal/vertical constraints
• 8 coincident constraints (one constraining each corner point to one of the lines)

When you use sketch mirror, every one of these objects needs to be duplicated.  In addition, each pair of duplicated geometries also gets a symmetry constraint added, to enforce the mirror.

You refer, in your post, multiple times to "changes in the timeline".  Can you elaborate what you mean here?  The timeline in a Fusion design is the row of features across the bottom:

all sketch operations will be contained in a single timeline entry.  Maybe this is just a terminology question.  Do you mean "changes to the sketch"?

Finally, it is best practice, most of the time, to mirror using solid features (body or feature mirror), not sketch mirror.  Sketch mirror is useful in some small cases, but for anything significant, sketch mirror will be very slow.

[ashydlyk]

Thank you

Still have questions:

When you use sketch mirror, every one of these objects needs to be duplicated.  In addition, each pair of duplicated geometries also gets a symmetry constraint added, to enforce the mirror.

So every time I mirror the sketch, return to it, edit it, mirror again and so on Fusion duplicates geometries (adding objects) and there is no option to clear such 'mirroring' duplications. That's why I have so many objects. Any ideas how to clear these duplicates and as a result to decrease number of objects?

Also there is no option to copy existing sketch without other hidden information (objects) or to clear this hidden information (objects). If I copy my sketch to another project it copying all these duplicated objects will be moved to the new file.

You refer, in your post, multiple times to "changes in the timeline".  Can you elaborate what you mean here?  The timeline in a Fusion design is the row of features across the bottom:

Sorry for my English) I mean to make changes in sketch/mirror/make changes/mirror this 'timeline'.

[davebYYPCU]

I am unable to make further comment, without access to the data you are referring to.

At the time you edit a sketch, you can not replay how it‘s articles were created.

Black, purple, and green articles can not be click dragged from their location, stability is paramount, 

blue, orange and white articles are not stable.

Sorry but for each sketch fillet, placed in the sketch, does add to the count,  a new curve, centre point and end points.  Alters the old corner.

Might help….

[TheCADWhisperer · Accepted solution]

---

@ashydlyk wrote:

When you use sketch mirror, every one of these objects needs to be duplicated. 

So every time I mirror the sketch, 

---

@ashydlyk 

It is almost never necessary to Mirror a sketch - this is computationally expensive.

There are more efficient techniques.

Mirror Component.

Mirror Body.

Mirror Feature/Faces.

[jeff_strater · Accepted solution]

"So every time I mirror the sketch, return to it, edit it, mirror again and so on Fusion duplicates geometries (adding objects) and there is no option to clear such 'mirroring' duplications. That's why I have so many objects. Any ideas how to clear these duplicates and as a result to decrease number of objects?"

besides the recommendations by myself and @TheCADWhisperer to try to avoid using mirror in sketch if you can, the answer to your question is:  yes,  if you execute multiple sketch mirror operations, then each one will duplicate the selected objects.  The question is:  why are you executing multiple sketch mirror operations?  Mirror should be considered a "one time" command - it creates the mirrored objects.  From then on, if you need to change the sketch, the symmetry constraints will update the mirrored objects.  For instance, if you change a sketch dimension, the mirrored object will update.  If you add new sketch geometry that needs to be mirrored, just use Sketch Mirror on those new elements, to prevent re-mirroring existing elements.