3d Model Cone

Hi, Wondering if anybody would be so kind as to show me how to cut
holes in a cone , I can draw the cone and its a solid cone for 3d printing, but
when i go to cut holes, i draw a cylinder and intersect faces to model, then when i go to
erase the cylinder out , it leaves open faces to the inside of the cone… Hope somebody can
understand me, and help… thank you in advance , so the end game would be a 3d printed cone , with 4 holes on each side of the cone ,

Make sure the cone and the cylinder are in the same context. That is, if the cone geometry is in a component or group, put the cylinder in the same component or group and then use Intersect Faces. erase the unneeded parts of the cylinder and delete the faces skinning the hole. You’ll wind up leaving part of the cylinder inside the cone.

Or, since you are using SketchUp Pro, make a cylinder group and use Subtract from the Solid Tools to cut the hole through the cone.

Thank you very Much… I got it with intersect faces, but i could not make solid tools work for me…
I tried but i’ve never worked with it, so im not familiar with solid tools.If your feeling Generous, Could you show me how the solid tools would work in this Situation , from modeling the cone to deleting the cylinder…Thank you for your Valuable time…

How big is this model ?

The problem might arise because of some tiny faces created by the intersection that have one or more of their bounding edges that are shorter than the lower threshold of SU (about 0.001 inch).

The solution is to scale up the model before doing the intersection or subtraction with the Solid Tools, then scale down when done.

It’s good that you got it sorted. I did a video showing how I would do this with the native solid tools starting from making the cone. I’ll send you the link in a PM.

As for the modeling for 3D printing, modeling at a larger scale as @jean_lemire_1 indicated makes sense. There’s really no need to scale up and scale back down, though. I just model as if meters are millimeters, export the .stl as meters and import into the slicer with the units set to millimeters. From a recent print job:

The model as exported to .stl.

The 3D printed parts. The belt is 20mm wide.