Which tool or extension? complex shape STL

I have a complex math shape that I’d like to create a base/plinth for… conoid.stl (1.4 MB)

Is there a tool I can create a face that wraps around the underneath shape?

You don’t really need an extension for that. You could model a cylinder and extrude it up through the surface, intersect the cylinder with the surface and then erase the part of the cylinder that extends above the surface.

Here’s the sketchup file… shape simplfied.
I would like the base to sit flush up to edge of wavy shape. Fountain02.skp (1.0 MB)

Thanks for your response Dave,
I’m new to sketchup… I cant find a way to create the wave shape on top of cylinder…
I’ve attched the sketchup file… any help would be appreciated.

Pull the cylinder up through the surface something like this.

Right click on the side of the cylinder and choose Intersect Faces>With Model. Then you should be able erase the cylinder above the surface.

You will need to work on this at a much greater scale than you currently have. There are so many tiny faces that SketchUp will create holes if it’s too small. since you are new to SketchUp, you should probably start with a much simpler model to learn how to use the the tools correctly before you dive into this one.

Dave has shown you how to make the shape, it’s quite simple. But the physical reality of the shape makes it basically impossible to construct in real life.
The center is a zero point, which doesn’t allow for the two parts to fit together. You may need to adjust the mathematics so the wave form isn’t vertical/horizontal.

Thanks Dave,

Should I reduce the number of polygons in the STL file? Computer is struggling… and what is the best way to do this?

I selected the outer edge of the shape and used vector push pull to get an accurate knit of the resulting cylinder to the original shape’s edge . My of been the size it came in at (1") but there are a number of repairs needed to the inner mesh.

Hi Dave,

I cant seem to delete the cylinder above??? Could you please send me your file? i’ll try and figure out what is happening…

I recreated your shape to eliminate the holes in the center. Maybe this will help.


conoid.skp (364.0 KB)


Thanks so much! Great help!

Sorry. I didn’t keep it. Looks like Jim has you sorted, though.

Reducing the number of polygons would certainly be a good idea.

I made an extension that covers most scenario…

instal using extension manager…

jcb_sine_circle.rbz (1.8 MB)