how can I convert a 3dspline into a pline?

[stenews]

Hi guys,

what I need to do is to flatten a spline into a pline because I need to measure its diameter.

I know how to it with a 2d spline but how can I manage in case I have a 3d one?

 

thanks a lot,

Stefano

 

P.S. for some unknown reason I can't attach my draw any more

[ReMark]

FlattenSpline.lsp by Joe Burke contained in message 4 of 15.

 

http://forums.autodesk.com/t5/Visual-LISP-AutoLISP-and-General/Flattening-3D-splines/td-p/1200164

 

Flatspline.lsp by kpblc in this thread.

 

http://www.cadtutor.net/forum/showthread.php?9615-3D-spline-to-2D-line&highlight=flatspline

[stenews]

Hi ReMark,

thanks a lot for your help, I'm really appreciating that

 

I'm not so confident with lsp routine...so be patient with me, please.

BTW, what I did is to copy and paste the kpblc's code in a note pad file and then I saved it like .lsp extension

Later that I loaded it from Tools>>AutoLisp>>Load application, searched for its location in my hard disk, and called it with the line command flatspline...I'm right??

 

Anyway it produce and error like this

Select objects: 1 found

 

Select objects:

; error: ActiveX Server returned an error: Invalid index

Where I'm wrong?

 

Thanks again

[ReMark]

You haven't done anything wrong. Did you notice however that the routine does work?

[stenews]

well...it does not seem to work...it deletes the spline

[ReMark]

For you maybe but not for me. It flattens it. I had to do a zoom extents to find it though.

[stenews]

I tried it...but I'm still in a trouble:(

 

Could you give me one more help?

[ReMark]

What kind of help? Did you try the other routine?

[stenews]

no...because I wasn't able to properly read its code.

 

P.S.

I'd like to post you my draw but I can't attach anything...I don't know why

helix_step.dwg

Edited January 13, 2012 by stenews

[ReMark]

What seems to be the problem with attaching a drawing? Can you at least upload it?

[stenews]

watch out the draw, explode it and try to convert the splines into a poli lines

[ReMark]

Is this what you wanted?

 

Helix Z at Zero.dwg

[stenews]

well...not really,

I just need to have a measure of the diameter of the rounded part of that helix steps

[ReMark]

I guess I assumed that since you specifically mentioned you needed to have a 3Dspline flatten that you were working with a 3Dspline and not a solid.

 

When I did my test of the lisp routine found here at CADTutor I used a 3Dspline and it did indeed flatten.

[ReMark]

The radius is 155. The length of the outermost arc would be 48.6947.

[eldon]

Am I being too simplistic about this? The aligned dimension (of the radius) is from the Centre of the arc to Perpendicular to the arc, using the drawing as is.

[ReMark]

Great minds think alike Eldon.

[stenews]

okay...you're nearly got it and now what about the radius of the lower part?

I mean the one that is underneath the 155 radius?

 

P.S.

I'm so sorry...I really did a terrible explanation

[ReMark]

The wall is the same width throughout its height. Shouldn't the radius remain the same?

[stenews]

have a look at this draw.

 

My CNC machine needs to know the radius of the surface that I used to slice the step underneath the tread of this step.

And it's a spline when I try to explode it....

helix_step.dwg