Sweep around a path that is intersecting

muchete

Hey there!

I'm new to Onshape so please excuse the stupid question, but I only want to sweep the triangle around the path that I imported. 



But apparently that doesn't work because the lines touch. Is there any way to solve this?

Greetings Michael

John_P_Desilets

Hello @muchete
 Can you post a link to your Document? This makes it easier for us to take a look at your example. Thanks!

owen_sparks

If you split the path and do two sweeps and then Boolean them together you should be good.

muchete

John_P_Desilets said:

Hello @muchete
 Can you post a link to your Document? This makes it easier for us to take a look at your example. Thanks!

Hey @John_P_Desilets
Sure: https://cad.onshape.com/documents/43783eb9617446f4553741fb/w/f098e9d5aabe3abd2aa981cb/e/395b55ff65488ada90113356

@owen_sparks
i tried this, but somehow it always shows errors when doing the sweep. It seems to be an issue of the surface thats within 

john_mcclary

That may be due to zero length geometry.  Try bumping the arc slightly above the intersection. .001" or so

steve_shubin

@muchete

https://cad.onshape.com/documents/e540f10f3118deac9bf81d59/w/ea376967b0711076de37fe97/e/be1109963c289667a65a1f48

  

muchete

steve_shubin said:

@muchete

https://cad.onshape.com/documents/e540f10f3118deac9bf81d59/w/ea376967b0711076de37fe97/e/be1109963c289667a65a1f48

  

Wow! Thannks a lot @steve@steve_shubin! 
But I don't quite get it. Should I have changed the radius of the L arch slightly? 

Anyway, solved my issue. Thank you.

steve_shubin

@muchete

The curve in the LOOK HERE sketch is too tight (small) for the sweep to work. This is part of the reason why you get the message that it intersects on itself when you try to do a sweep. 

So, I made a new sketch (Sketch 1) which is NOT as tight

I also reduced the width of the base of the triangle that I used in the sweeps from .299 to .28

Doing both of the above allowed me to make what you see in the document that I have a link to, in my above post

Watch the below animation

steve_shubin

@muchete

If you’re going to have the problem of a self intersecting sweep, It’s likely it’s the inside of the curve along the sweep that intersects with itself. Because the inside of the curve is making a smaller or tighter turn then your path, and that’s usually where you start getting these self intersecting problems.

In the below animation, I have it set to do a SURFACE sweep. Now in this animation, I am using your path, which is the LOOK HERE sketch. And I’m also using your triangle as the shape to sweep.

Notice how I select the left side of the triangle first and try to get it to sweep. It fails.

Then I select the base to sweep and it fails.

The two above fail because they’re trying to make a tighter radius then your path has. And as is, your path has too tight of a curve to allow these two segments to make a sweep

But I am able to select the right side of the triangle as it goes counterclockwise around the curve, as this face is making a larger radius and there is no self intersecting that occurs

So, my solution was to make a looser curve, and make the base narrower. And doing these two allowed what you see in my above document