Open loops that won't close

[Slinger1010]

I have a part I'm making for a friend and I can't seem to close the open loops in the sketch, can someone have a look and inform me what I'm missing.

 

Ron

ABS Rotor.ipt

[Bishop]

Patterned sketch geometry doesn't always work out as far as closing loops goes.

 

I'm assuming you want to extrude that?

 

Sketch out one section of it, and rather than patterning the sketch, just extrude the one section of it and then pattern the extrusion feature.

[KennyJ]

From what I can see, Your transitions from arc to arc should be tangent and they are not. Also the sketch is fully constrained and in order to close the loops some of the sketch geometry will need to slightly change. The sketch geometry can not change due to the constraints. Edit your sketch, delete the problem constraints or dimensions, Make the arcs transition from one another with a tangent constraint this should fix your problem. Hope this helps!

[JD Mather]

In addition to the other suggestions I recommend that you turn off AutoProject Edges on Sketch Create or at least turn all that to construction before creating your sketch.

[ecshclark]

I avoid patterning sketch geometry like the plague! I pattern features instead. I find patterned geometry does not seem to combine with other geometry well enough too create closed profiles. You end up with multiple sketch points on top of of another, open loops etc... Plus, you can not add new geometry to existing sketch patterns in edit mode. You have to delete the pattern, and recreate it adding the new geometry. A real pain if you find out you missed picking one line. Keep sketches as simple as possible. I would do this area of the part using three features. I would create one sketch with the 3.275 radius as a full circle, and extrude the slotted holes as a cylindrical feature without the outer hole bosses. Then draw another sketch of a boss around one of the outer thru holes. Draw the two .500 radii on each side of the boss using the fillet command. Everything should be automatically tangent (I'm not sure why you used linear dimensions at the ends of the fillets, leaving sharp corners and no smooth tangent points). Extrude the boss, same distance as the prior extrude, or different distance, just because you can now. Then use Circular Pattern on the Boss feature. Done, no muss, no fuss, and you don't have to deal with 50 billion contriansts in a difficult to maintain sketch.

[Slinger1010]

Thanks, I patterned the features instead and it worked out well.

 

Ron