My approach to drawing this cord was to draw the line longer than I needed, adjust its distance from the tangent, then trim the excess. After I do this (and the trim places dots where the cord appears to meet the circle) and regenerate, I get an intersection and loop error (both unhealable). If I zoom in on the cord ends, I can see they're not on the circle. If I try to trim again it wants to delete the whole cord. What am I doing wrong? Thanks.
Trouble drawing a cord
- Thread starter Involute
- Start date
Thanks for your reply, bigseb. I'm on an iPad at the moment and can't look at your file, but I don't want to trim the circle, just the line ends to get a proper cord. Then I want to extrude the lesser part of the circle normal to the circle. Unless there's a better way to get that result, though I'd still like to know why I can't get the cord.
You need to trim off the larger segment of the circle. In order to create a feature, the outline must be 'closed'. This means that the outline must follow a single track and end at the same point it starts from.
A sketch can contain several closed outlines. They cannot intersect each other so must be entirely independent or entirely contained one within another. Reference lines do not form part of the closed outline.
If the outer circle is needed for the geometry, change it to a reference line. Then add an arc between the chord ends. Use equal and concentric contstraints to ensure that the arc aligns with the reference circle.
Make sure you fully understand the concept of closed sketches. Sketch | Analysis will show where any sketch problems are.
A sketch can contain several closed outlines. They cannot intersect each other so must be entirely independent or entirely contained one within another. Reference lines do not form part of the closed outline.
If the outer circle is needed for the geometry, change it to a reference line. Then add an arc between the chord ends. Use equal and concentric contstraints to ensure that the arc aligns with the reference circle.
Make sure you fully understand the concept of closed sketches. Sketch | Analysis will show where any sketch problems are.
dwc
Alibre Super User
Involute said:
They are not healable because any intersection is not allowed in a sketch. Sketches must be closed, non-intersecting loops in order for them to make an extrusion. Delete both the portions of the line AND the circle that are not part of the figure to be extruded and it will work. I do this all the time.
Don
Just a reference.
http://www.youtube.com/watch?v=373Uh9NZTeU
As is often the case, in the reality, the shown method won't work as intended (by me...)though.
At least, it will not beep saying line is intersecting.... as far as it is concerned. :roll:
http://www.youtube.com/watch?v=373Uh9NZTeU
As is often the case, in the reality, the shown method won't work as intended (by me...)though.
At least, it will not beep saying line is intersecting.... as far as it is concerned. :roll:
Attachments
NateLiquidGravity
Alibre Super User
Looks good Toshi. For what its worth Solidworks and Inventor have had the ability to pick any full loop/regions or profile objects you want and the ability to make multiple features from a single sketch for years. Matter of fact I think it was my first question when I joined these forums back in 2008 and they had it for years at that time: http://www.alibre.com/forum/viewtopic.php?f=10&t=6367
