topic Re: Flattening solids for cnc in AutoCAD Forum

Flattening solids for cnc

sfiforeman — Tue, 24 Oct 2017 20:37:44 GMT

ok so i'm drawing exclusively in 3d. so much better workflow. the problem is when i flatten a curved solid it gets converted to a polyline. not a good thing when i send it out to get cnc routered and the piece comes back all faceted and not smooth. is there a way to keep the smooth curves when i flatten a solid? It would be stupid to recreate my parts in 2D just to get stuff cut out.

Re: Flattening solids for cnc

john.vellek — Tue, 24 Oct 2017 20:54:04 GMT

Hi @sfiforeman,

Are you able to share a sample file that contain your curved solids as well as a file that shows how it gets flattened into polylines? I would like to explore some options to see if this process can be improved for you.

When I flatten a curved solid and get polylines, I can select the polyline, rt-click and select SPLINE Fit.

Re: Flattening solids for cnc

sfiforeman — Tue, 24 Oct 2017 21:03:42 GMT

file attached. seems like converting to spline works, I didn't know of that as a solution. In the situation in my file, it looks like I have to FLATTEN, BREAK at the vertices, PEDIT, convert to spline, then LINE to connect the two arcs. Maybe there's a better method. It adds a lot of commands, especially when I've got a lot of little weird pieces to get cut out... second file is what I just had cut out, not realizing it was a polyline. Luckily we were able to make it work with the facets. Still a pain though...

Re: Flattening solids for cnc

Anonymous — Wed, 25 Oct 2017 17:24:40 GMT

have you tried FLATSHOT? That will convert the curves into arcs which should be fine for CNC...

Re: Flattening solids for cnc

john.vellek — Thu, 26 Oct 2017 17:48:08 GMT

HI @sfiforeman,

I took another look at your model this morning. While Flatshot might work in my experience it usually ends up sort of crude and messy.

Sine you are working with solids, try using XEDGES to grab the edges. They show up as arcs on my side. I can then use flatten and overkill and still end up with 2D arcs.

I made a quick video showing this process. Does this do what you are looking for?

Please select the Accept as Solution button if my post solves your issue or answers your question.