Open loop - multiple sketch points

[stevensarns]

Any help greatly appreciated...

 

Using Autodesk Inventor 2009 SP1 - I draw a square using the line tool and clicking once at the beginning and then once at the end of each segment. Finish Sketch. Then I try to Extrude. Extrude fails to recognize the square because it finds "open loops". The sketch doctor tools says"

 

"Multiple sketch points exist at the same location. Use Combine Sketch Points to create a single sketch point at each location."

 

Each of the 4 line segments appear to have multiple sketch points at the endpoints. After combining the multiple sketch points (using Sketch Doctor), the extrude works.

 

This problem has manifested after many drawings. I suspect that I have messed up some setting in the system, but I have been through all of the options that I can find and cannot figure out what has changed.

 

This is first time I have posted to a forum, so please excuse any dummies on my part.

[kencaz]

I draw a square using the line tool and clicking once at the beginning and then once at the end of each segment.

 

It should only take five points to make a closed square in your sketch using the line tool. Are you using more points then that?

 

Also, check that you don't have snap to grid "on" or you may not be snapping to the lines end points.

 

Secondly, if your making a square it's easier to either use the rectangle tool or make a 4 sided polygon then you'll be sure that it's closed.

 

KC

[JD Mather]

Constraint Persistence F1

[stevensarns]

Thank you both for the replies.

 

"I" am not using any points. I am using the line tool to draw a continuous line depicting a square (or better - a triangle). I click only at the end of each segment before I start off in a new direction on the next segment. A triangle takes 4 clicks; one to start and one at the end of each segment. (note - I say left mouse clicks, you say points)

 

I do have snap to grid on, but the line segments are not drawn in an individual manner. However, I turned "Snap to grid off" and nothing changed. An extrusion still cannot be made until the multiple sketch points are combined.

 

(using the Rectangle tool creates a figure that extrudes successfully)

 

"Constraint Persistence F1" - I attempted this as well, turning on/off Constraint Persistence and Constraint Inference (4 combinations) using the buttons on the sketch toolbar - no change. I do not think this is applicable because of the previous experiment wherein I drew a triangle with snap turned off whose sides bore no relationship to one another. This also failed to extrude.

[JD Mather]

This also failed to extrude.

 

See this

http://www.cadtutor.net/forum/showthread.php?t=44527

then attach your file here.

 

I have never used snap to grid since 1987. In fact I do not even use a grid.

http://home.pct.edu/~jmather/AU2006/MA13-3%20Mather.pdf

[stevensarns]

J.D. !!! Thanks. The thread you suggested illustrated what had happened to me - all constraint options were cleared. Select All in Constraint Options solved the problem.

 

I will consider your point about grids. Thank you again.