close contour

[ben_mtl]

Hi there,

 

I've been looking here and there to find a solution to my problem, found lots of things but none worked for me !

 

here is my problem :

I want to have some parts CNC machined, the guy wants DXF file. The thing is I'm used to work with Catia (all parametric design) so I modeled my parts in 3D with Catia, them made a 2D and converted this 2D into a DXF file. The pieces are templates to cut ski parts so it's basically the top view of a ski, meaning lots of tangent curves.

I know the 2D in Catia are not perfect (some approximations when going from 3D to 2D I guess) so my profiles are not closed or sometimes lines are overlapping (only visible when zoomed at maximium)

 

Anyway when I have my DXF I tweak it a bit, moving points here and there to have a continuous contour. The thing is my contours are never closed, even if visually I can see no gap at all, and that gives trouble to the CAM software at the CNC shop.

 

On my end, to check for closed contours I try to apply hatching to the contour by picking a point inside, it always return the "open contour" error.

The problem is I can't see where the contour is open.

 

Is there a way for AutoCAD to show that to me so I can fix it ? (I use AutoCAD 2006, and I'm also giving a try to 2010 as I like the parametric design feature... still have to get used to it though..)

Is there a command to close a contour or create a line linking the ends of 2 curves ? (even if visually they're already linked)

 

Any help would be very appreciated, I've been trying to fix that for 2 days and start to be out of ressources...

I can provide the faulty DXF file if some wants to have a look.

 

Thanks a lot !

Ben

 

(sorry for my english it's not my first language..)

[Patrick Hughes]

Closing contours can be labor intensive, one approach I've taken is select an item using grips, zoom in tight to the gripped endpoints and then stretch to the nearby endpoint. A better approach may be to search for a lisp file that can "weed" the linework joining endpoints based on a fuzz factor. Also examine the linework to see if you are dealing with linework of varying Z values.

 

If these are not polylines you can attempt to convert one of the objects into a polyline then join the other members. You will receive feedback as to how many objects were added to the polyline - if the number of items is fewer than what you've selected you can visually see which objects were excluded by selecting the newly created polyline and observing the non-highlighted segments. You may need to perform this sequence several times, sometimes exploding the polyline and repeating.

[ben_mtl]

hum interesting, I didn't even suspect having lines on different z axis... I'll check that as soon as i'm back home !

Thanks for all the other inputs, I already tried moving the grips, it worked visually but it's not fixing the problem...

I'll investigate a bit more on polylines but my lines are arcs, I'm afraid I'll end up with lots of straight lines whic approximate my curve...

Thanks !

[Patrick Hughes]

Polylines can consist of arcs, you should be ok there.