Problem with Fusion offsetting a somewhat complex sketch.

[srunyon13KPGB]

I have a sketch I can extrude the whole sketch fine.

I want to add a 3mm offset and make that a separate extrusion, it fights me, I get maybe three points that are white dots, I have tried so many things to try and fix them. I do not see any breaks in the lines. but it will not select that area. If i start removing and adding lines it just doesn't seem to behave at all. things start moving and jumping around and the next thing i know its a mess. I have some inventor background but very old versions, there are things there to fix sketch problems but I can't find anything here.

If i do a big offset like 18 mm and i have match topology unchecked I can get a section that i can select.  I have spent so many hours on what I think should be easy work but it just isn't

any help would be great.

[g-andresen]

Hi,

1. an offset with activated “match toplogy” is only possible to the extent that there is no self-intersection between vectors.
2. white dots indicate open vectors > breaks
3. the offset can be omitted if you select the “Thin lines” option during extrusion and then extrude the desired sides to “their” height.

günther

[g-andresen]

Hi,

The devide and conquer method helps to detect breaks.

günther

[johnsonshiue]

Hi! Another approach to consider is to extrude the sketch as a surface body. Then create an offset surface from the extruded surface. Or thicken the surface to create the thin wall.

Many thanks!

[srunyon13KPGB]

Thanks but I'm not sure how to do either but I will try.

the thing is I want the gap around that piece so I would extrude only the outer, its like trying to make a box with a gap for the inner piece and then later a lid out out of the same drawing.  I think if i extrude each face it would get really hard to manage.  

[srunyon13KPGB]

When selecting thin line it will not extrude at all. it fails.

I do not have Match topology checked and it still fails except when I make the offset much bigger.

When I zoom in on those dots , yes hey look connected, how do I fix them? Adding new lines just don't work.

What I'm trying to do is to have that gap around the inner piece . 

it just seems so close to doing what I want .

thanks for your help.

Steve

[TheCADWhisperer]

@srunyon13KPGB 

I only completed part of the spline as a demonstration, but I think it will work as one continous spline.  You can adjust handles if needed but first try without adjusting handles.

[srunyon13KPGB · Accepted solution]

Thanks but i ended up working on the dfx file i importated and that may fix the issues