Explode Sketch Curves/lines

[matthewrjacobs]

I have a Lute Rose  that I've sketched,  however I'm getting weird faces/grouping of curves,  that make extruding the piece useless.   Ultimately I'd like to extrude the "strips" and cut anything in between.   

I'd like  to get the faces to "explode".  I tried breaking all the lines and selecting the lines of the boundary I want but it hasn't worked.   Is there an explode command?

Here is a pic of the faces that it's forming.

[wmhazzard]

See all these white dots on your sketch, they mean that the lines are not connected, you can grab them and move them so they will only extrude where they are connected. For what your are doing, I assume that dimensions are not critical, you should edit the sketch and use the fix command and fix the lines, but not the end points, you can then use the coincident constraint to fix the end points of the lines to their respective lines. 

[wmhazzard]

On a side note, that is a bad way to sketch. Sketches should be kept as simple as possible and when you have something like you have where there is a repeating pattern, you should sketch the absolute minimum, extrude and use a circular or rectangular pattern on bodies and then combine. You should also fully define your sketches so all the lines are locked down and turned black in your case. 

[matthewrjacobs]

I must have uploaded a version of the file after I broke all the lines.  below is the version I have saved.   the lines a are black, so I thought I was fully constrained,  but I still have a bunch of white dots  so I guess not.

I tried to extrude first and then do a circular pattern,   but I couldn't get it to work.  probably because it wasn't really constrained.    I'll take a crack at it and see if I can get it to work this time.

Thanks

[wmhazzard]

Autodesk calls a line fully constrained even if the ends are free to move, that is why your lines are black even when the lines are not connected to each other. I disagree with their logic but my opinion doesn't really matter. I say if the end points are free to move, then the sketch is not fully constrained. 

[jeff_strater · Accepted solution]

@matthewrjacobs - I spent some time with the design you posted.  I found several problems:

1. the white dots that @wmhazzard pointed out.
2. overlapping geometry - Lots of duplicate lines and arcs on top of each other.  This can really confuse the profile algorithm in Fusion
3. a few cases of "degenerate lines", where points had collapsed onto each other

after cleaning all this up, it seems like all the profiles are correctly identified

the fixed model is attached, if you are interested

[matthewrjacobs]

@jeff_strater ,   you're a saint!   Thanks so much.

I have a couple of questions:

1.  Is there a way fusion will tell you if you have overlapping-duplicate lines, and a way to select only the duplicates?   I thought the black dots represented stacked geometry,  but when I tried to erase those lines most of the time it erased everything.

2. You must have added the arc (runs from 11 o'clock to 7 o'clock) back into the drawing, it crossesover over in some places where I don't want it (green circles).  If I trim them it breaks everything back up and I can't extrude anymore.   Any fixes?

Cheers!

[g-andresen]

Hi,

I am not aware of any application that can perform such tasks at the push of a button or with minimal effort.
The example of double lines can be used to explain one reason.
If two neighbouring geometries each have a boundary line at the same position, these cannot (must not) necessarily be regarded as double lines.
The question then arises as to the definition of "double line".

günther

[laughingcreek · Accepted solution]

the sketch engine in fusion doesn't lend itself to large freeform type sketch practices.  that's b/c it is the bases for parametric modeling.  simpler sketches perform better.  the are also "simpler" to sketch.

IDK what your end game here is, but if you want the ability to able to easily adjust the model, or to do fancier stuff with it later (like making a weave pattern) embracing the approaches required for parametric modeling in fusion would be a good idea.

look at the attached model.  the first sketch just took a few moments to make, and is easily adjusted by changing the 3 dimensions circled in the pic below (you don't have to edit the sketch to change dims.  just double click on it right in the modeling environment, make a change, watch the result)-

[jeff_strater]

@matthewrjacobs - there is no automatic tool that will repair these kinds of problems.  It would be good to have, certainly.  When I was working with your sketch, I was admittedly not all that focused on getting the "right" answer, so not surprising I missed some things.  I recorded the screencast below to try to help illustrate the kinds of things I did to repair the sketch.  The main technique I use to find duplicates is Select Other - hold down the left mouse button for about  1/2 second, and it will pop up a dialog with all the geometry that is under the cursor.  As you scroll through the list, you can see that they overlap.  I deleted one unnecessary arc, and then used Coincident to hook back up a few adjoining lines, then was able to trim off the small segment - overlapping curves also confuse Trim.

[matthewrjacobs]

Hi @laughingcreek,

Thanks for all the help.    I really struggled with getting the bare minimum sketch that would result in the complete design when C-patterned,  so kudo's to you.

I noticed that you created a projection of the patterned design (sketch 9),  I'm not sure why it's there,  I'm guessing it's so I could draw lines for a weave pattern.  Am I correct?

[matthewrjacobs]

Hi @jeff_strater,

I guess it didn't occur to me to us the hold down the left button in the sketch environment,  I use it all the time elsewhere.   Thanks for the tip.  

[laughingcreek]

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@matthewrjacobs wrote:

Hi @laughingcreek,

Thanks for all the help.    I really struggled with getting the bare minimum sketch

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That skill is needed to unlock the abilities of fusion.  with out good simple sketches, fusion's not much more than a fiddly direct modeler that tends to break because of the timeline tuff.  looking at a pic of that desing it was pretty apparent what needed to be patterned.  not much differn than the original designers did it.  just different tools.  a computer instead of a wood pattern and chalk 

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I noticed that you created a projection of the patterned design (sketch 9),  I'm not sure why it's there

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The reason it's there should become apparent if you step through the timeline and examine what's been done.  that sketch is there to define the profiles for the extruded arcs around the edges, that then also get patterned (though in hind site it would have been simple enough to just manually extrude them all)-

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