[oorst]

Recently began looking into signs and other abstract pieces after having only done rectangular pieces for cabinets and furniture. Was also approached to produce internal elements of upholstered furniture (which require various curves).

Someone who wanted some signage produced supplied me with a DXF file that was created in Adobe Illustrator. Biesse Works did not like it.

After some tinkering and research, I discovered that bezier, spline and b spline curves are not readily machinable. Presumably this is because these types of curves are not mathematically defined (at least not usefully mathematically defined).

How then can one machine these irregular curve types? There must be a way. Do the curves that are readily machinable have a collective name or category that they belong to? Is there a way to convert bezier, spline curves, etc. into machinable curves? What have people been doing in order to create abstract shapes on a cnc router?

Thanks for your help.

[Dylwad]

I have to explode them into polylines, and you should be able to set the segment length of the polyline in cad when you explode, so the curve becomes small lines, small enough that you don't notice them in the finished product. Can be very frustrating though! Seems the more expensive cam software handles it better. This can also cause issues when cutting depending on how your machine controller handles things, like constant velocity vs exact stop mode.
Sometimes you can make the curve into a series of arcs blended together too, but it's tedious.

Doing text work without dedicated engraving/sign making software can make your head spin. I do a lot of single line text engraving and had to trace over the text in cad to get good results, and keep an alphabet file handy, and do the typesetting manually.

[ger21]

After some tinkering and research, I discovered that bezier, spline and b spline curves are not readily machinable. Presumably this is because these types of curves are not mathematically defined (at least not usefully mathematically defined).

Because there is no g-code for them, so they need to be converted to short, straight line segments or regular arc segments.

How you deal with them depends on what software you have available to you. My preference would be to redraw them using arcs in AutoCAD. These cut much better on our MOrbidelli than short straight segments.