ARC Converions in Rhino

Hi creating some files which will be used manufacture parts on a CNC Punch. The punch software reads the circle size imformation to punch the correct hole and position on the part. I used an illustrator effect to create the hole positions which I imported into rhino. If your turn control points on for the geometry you can see they come as splines rather than circles - if I use the convert to arc command some convert perfectly while others convert randomly and this varies even according to size.

If someone could offer any advice would be great.

ARC Conversion.3dm (2.9 MB)

Hi Alex - see how this quick script works - To use the script, extract and save the .rvb file from the attached zip archive, then drag and drop the saved rvb over an open Rhino v5 window. This will load the script, set it up to load on startup in the future and register the alias


that will run the script much like a regular command. An alias can be typed or added to a toolbar button or keyboard shortcut (F-key). Note: This is a very quick hack that looks for exactly the type of curve that you’re getting from AI, it is not a general fitter of circles to approximate circles. (623 Bytes)


Hi Pascal,

  Many thanks for the script worked a treat - opens up the toolbox
  to a wider array pattern generators.

  Here is some of our work all generated and output through rhino.


  ^ Metal Stone Wood

46 Coopers Lane South
Main Arm 2482 NSW Australia
p+ 612 6684 5069
m+ 0428 606 006
f+ 612 8569 0511

Hi Alex- good, I’m glad that worked out-

It looks like you might want to take a look at Grasshopper, if you have not already tried it -