Issue with Cylinder

Hi All,

I am about to cut out a shape from a cylindrical solid. I have tried splitting surfaces, boolean, wirecut, explode/trim so far, non works.

Boolean ops fail because the cutting surface does not reach over the corresponding solid surfaces. (?)
Wirecut could seemingly work if I could set the cutting angle (a little to Y, Z axis movement).

Could somebody advise, pls?

Hi Gabe- please post the input object - it is not clear to me what you’re starting with and what you want as a result.



Hi Pascal,

I have uploaded an image of 2 objects - the right one is what I want to make from the left one.

I found a link - - showing an istance of cuttling massives, still, no hint of the name of the tool, and I am not sure it would work with a cylindrical object.

many thanks for your prompt feedback!

Hi Gabe -It really would be much better to have a Rhino file. Your objects look a little suspicious to me…


Box.3dm (105.4 KB)

Hi Pascal,

hope they open and will be of help.

1st image is a box as instance.
2nd image is the cylinder fragment with the contours of the cut intended (upper right corner of the cylindrical object should fall out).

gabeCylinder fragment.3dm (566.3 KB)

Hi Gabe - a plane that corresponds to the two lines on your object does not intersect the cylindrical surface the same as that curve you have there - so either the cutting surface is not planar or the shape it makes is not the same - in any case, BooleanDifference the plane in the attached file from the solid - is that about right?

Cylinder fragment_PG.3dm (416.7 KB)


Hi Pascal,

the red curves are the solution. Boolean operations still don’t work but extending the plane does.

thx again!

Hi Pascal,

when I have something else to ask about, am I suposed to open a different dialogue or I may go on with this one?
Anyway, the question is as follows -

I would like to construct a pyramid with possibly even figures for the crease angle dimensions (the four sides of the pyramid.
I extrude the base curve to point and get the solid - is there any means to track or set the angles during the operation?

thx, gabe

Hi Gabe - no there isn’t - I guess I’d work out the angles ahead of time and make the height and size of the base accordingly,