Changing Circles to Points in AutoCAD LT 2010

Do you want to end up with only the center points or you want to change the circumference- line type in dotted line?

Are the circles in a separate layer? Or a specific color?

What version of Autocad are you using?

The version is 2010 LT.

My original idea was to change the circle to be just the centre point. But as it turns out our machine's software will not read a point within the DXF file. It actually needs to have some small dimension/size to it. So instead now i need it to be a very short line (e.g. 2um) starting from the circle centre point.

All of the cirlces are of the same layer and same colour. But it might be better if the points/lines can be created onto a different layer.

The difficulty is just arrising from the number of features that need to be modified.

Thanks.

Could it be the circles are not the problem? Is it possible the chaining was done incorrectly and the cutter comp was set to the outside instead of the inside of the circle? That would explain not being able to make a small hole with the current diameter but being able to do so with a line.

unlike other cad platforms, the starting and ending point can be concurrent (same) in Autocad.

JohnDG #14
has a somewhat good reply....of course you still need a program.

And with the amount of enitities you have, manually is out of the question.

Can you change all the circle radii to some small value?

Would it work if you modified all the circles to have very small radii?

I don't know about LT, but I just tried this with ACAD 2007:

In a drawing with an assortment of lines, circles, rectangles etc.

• Use 'Quick select' to select all the circles (you can select only circles of a specific size if necessary)
  
• Use 'Modify properties' to change all the radii to 0.000001

Thanks for the suggestions guys.

Unfortunately, the machine will follow the profile of the circle causing the resulting hole to actually be bigger and deeper than desired. Reducing the radius of the circle still results in the same size hole being cut. The current circle is already below the smallest capability for the machine to process a circle/hole. But if just a point or very short line then it can produce a smaller hole.

The only way i have found to get the drilled/cut feature close to the size I need (or at least the smallest possible for the machine) is to replace the circle with a very small line at the centre point. Which is where my problem lies as there are 13,000 circles to replace.

That's really weird. Presumably the actual cutting device has a kerf width, or beam/nozzle diameter; call it D. If the device follows a line 2μ long, it will cut a D x D+2μ obround. If it follows a circle of diameter 2μ, the cut will be a circle of diameter D+2μ. Because 2μ is so small, these shapes should be visually indistinguishable.

For similar application I had developed macro program and submitted to one of the clients in Canada as an assignment On similar lines this can be done.

Then can you share , how to do macros in autocad . i will be more useful for many if can explain this by screen shot.

Please explain more about the application/machine tool.

We are all finding it difficult to understand how the "machine" can interpret a very small circle different to a very short line.

I'm a bit rusty in LT but could you you use the BLOCK command to convert all of the circles to blocks. If you then create another block from your small line you can replace all of your circle blocks with line blocks.

I have to admit that I'm struggling to remember the process to replace all of one type of block with another, maybe someone can jump in here to help?

Are the circles actually blocks by any chance? If so just edit the block to whatever you want them to look like and all of them will change automatically to the new block.

In my previous life, I was a CNC programmer, and I had wrote a lisp routine to do just that. Used the points for a canned drill cycle.

13,000 circle..... about a minute....

It puts a node right at the center. PM me with your email and I'll send it to you tonight.

(if you needed changes the node to differtiate to the size of the circle to a different layer or color, I would need to do some adjustments)

I'm back and I just saw your version being LT. LISP does not work, does it.

If you can program (or you've got a friend who can) you could write a bit of code to go though the dxf file, replacing all the circles with lines.

This is the dxf code for a circle (my comments in bold):

0
CIRCLE
5
E5
330
1F
100
AcDbEntity
8
0
100
AcDbCircle
10
170.0 X co-ord of center
20
180.0 Y co-ord of center
30
0.0 Z co-ord of center
40
1.0 Radius

This is the code for a short line starting at the circle center:

0
LINE
5
EF
330
1F
100
AcDbEntity
8
0
100
AcDbLine
10
170.0 X1
20
180.0 Y1
30
0.0 Z1
11
170.00000001 X2
21
180.00000001 Y2
31
0.0 Z2

May take a bit of trial-and-error, but it'll save a lot of time if you can get it going. BTW, the dxf is just a text file, so you could open it in a text editor (e.g. Notepad).

If you select all the circles and then click on "Properties"you should be able to reduce the diameter of the circles to 0.00000001mm diameter. Would that be small enough?

Try this code ....refer....from ....http://www.cadtutor.net/forum/showthread.php?1390-How-to-use-the-LISP-routines-in-this-archive....................

(defun c:test (/ ss n sset)
(if (setq ss (ssget "_:L" '((0 . "CIRCLE"))))
(repeat
(setq n (sslength ss))
(setq sset (ssname ss (setq n (1- n))))
(entmakex (list (cons 0 "POINT") (assoc 10 (entget sset))))
(entdel sset)
)
(princ)
)
(princ)
)

LISP in Autocad LT?