Joining surfaces into one for CNC


Hello everyone,

I was wondering if you could help me out on a project I’m working on.
I am new to Rhino so I’m struggling with this project a lot. This is a model of a ceiling that is supposed to be made into a mold with a CNC and then casted with polyester.
I made each “leaf” with Suface from network curves and tried to fillet surfaces to get a single surface. It didn’t work all the way. I tried using the drape command but it ended up really jagged.
What would be the best way to make this form into one single surface that could be CNC’ed?

One more thing, the surfaces should blend into one (at the top of the image). How could this be achieved?

forum.3dm (731.4 KB)


You would have to first trim the surfaces to each other and then join into one **poly**surface (you can’t have a single surface in this case), but that looks lik it is going to e somewhat complicated… However, depending on your CAM software, you might be able to get away with just running your toolpaths over the unjoined overlapping surfaces. Generally CAM softwar projects the toolpaths onto the surface(s) and ignores anything below the first surface it hits.



It’ll be tough but not impossible… Try ending with a common shape where I’ve marked A. If you can remodel your surfaces so that they sweep/loft/flow into part of all of that cross section you should be able to create a decent attempt at that end.

Try working with a circle in plan where I’ve illustrated B-B you can take a section or ExtractIsocurve using Knot to snap to. From there you can _Sweep1 to create that part - you may have to play with the section there to ensure it’s accurate.

Working in plan when you have your parts use the Intersect command to highlight where the surfaces intersect, - project to Cplane Join and then extend curve either by line or by arc and then trim off the bits you don’t need.

This will get you to a partial working surface - from there you can BlendSrf and/or maybe use the SplitEdge command.