When I explode it Disappears!

[nodnud]

CAD Users,

 

I have recently upgraded to Autocad Mechanical 2009 and have created a range of "Generic" type arrangements and saved them as DWG files.

 

I then insert the "Generic" arrangements by using the "Insert block" feature and selecting the saved DWG file.

 

When I try using the explode feature, it disappears all together. I try zooming extends and nothing is there!

 

Anyy suggestions would be appreciated!

 

Cheers

 

JD

[rkent]

CAD Users,

 

I have recently upgraded to Autocad Mechanical 2009 and have created a range of "Generic" type arrangements and saved them as DWG files.

 

I then insert the "Generic" arrangements by using the "Insert block" feature and selecting the saved DWG file.

 

When I try using the explode feature, it disappears all together. I try zooming extends and nothing is there!

 

Anyy suggestions would be appreciated!

 

Cheers

 

JD

 

First thing to try, thaw and turn on all layers, zoom extents.

[nodnud]

Hi rkent,

 

Can you please explain your advise step by step.

 

Cheers

 

JD

[rkent]

Hi rkent,

 

Can you please explain your advise step by step.

 

Cheers

 

JD

After you explode and it has disappeared, thaw all layers, turn all layers on, Zoom, Extents

[rayg11757]

I just came across this post, as I am having a similar problem. In my case, the hatch scale is set to a very small value, and the hatch disappears when it is exploded. However, if I modify the hatch scale to a larger value, the hatch explodes properly. Personally, I still need to explode and retain the dense hatch objects, even though the hatch explodes to a large number of entities. (Sigh... I miss 2006)

 

I suspect your problem may have to do with the "hatch density" and possibly a low value for the "MaxHatch" environment variable:

 
(setenv "MaxHatch" "10000000")

http://docs.autodesk.com/ACD/2010/ENU/AutoCAD%202010%20User%20Documentation/index.html?url=WS1a9193826455f5ffa23ce210c4a30acaf-65b9.htm,topicNumber=d0e114230

Edited January 11, 2013 by rayg11757

[ReMark]

It is never a good idea to start exploding hatch patterns.

[rayg11757]

Generally I agree 100% - hatch patterns should always be associative, but I think there are exceptions to the rule.

 

In my case I inserted an exploded *line hatch in AutoCAD 2006, where I used the start and end points of each line to do numerical integration in a lisp program. The program no longer works in 2013 because I cannot get past the dense hatching limitations that have been imposed. Without dense line spacing, the accuracy is unacceptable. The hatch command is ideal for my application, as it picks up all discontinuities in the shape.

 

As another exception, I came across an on-line post where the cad operator was using an exploded dense hatch to generate very fine CNC tool paths for a laser operation.

 

I think the MaxHatch environment variable is a great idea for most cases, but I don't think the user should be limited by the software.

[irneb]

I'm just wondering ... can one obtain the anonymous block definition of the hatch (those starting with "*X" as their name)? If so you wouldn't need to explode them at all, simply work with their definition as you would through any other block.

 

And anyway, if it's such a "simple" pattern as lines at a specified offset distance, then it's not too difficult to calculate the lines and derive the intersections with the borders. I would try my damnedest to avoid exploding wherever I can. It tends to break all sorts of stuff. Or alternatively, have you tried the vlax-curve-* functions instead to figure discontinuities?

[rayg11757]

nodnud- Not sure if you are still interested in this topic, but I had lots of luck from this site. I am attaching the two links that solved my problem.

irneb - Thank you for the suggestion. In my case I was looking for hatches that can span odd shapes having breaks or disconntinuities, so the hatch command is ideal. The two things that helped were the system variable HPMAXAREAS

(command "setvar" "hpmaxareas" 0) and the environment variable (setenv "MaxHatch" "1000000000") - courtesy of GP_ and BIGAL. The first variable sets the hatch pattern to "legacy" when set to 0, and the second variable permits extremely large quantities of hatch lines.

http://www.cadtutor.net/forum/showthread.php?76302-LISP-to-get-past-the-quot-Dense-Hatch-Pattern-quot-Dialog-Box

http://www.cadtutor.net/forum/showthread.php?76674-Lisp-code-to-set-the-HPMAXAREAS-variable.&p=517630