Redesigning, Simply differencing two solids and solid infill

I am new to Rhino however I have been managing it alright, until now. I am trying to redesign a plastic piece for my dirt bike, it fits on the handle down tube and lubricates to make for easy turning. It is a very simple piece, I started by making a solid square the size of the object. I then made a cylinder and differenced out the centre. There is a channel running perpendicular to the direction of the cylinder that disperses oil onto the down tube.

  • I am having issues differencing two solids, i.e removing a cylinder solid from another solid.
  • Cutting a object in half, I know its simple but I think im making it more difficult then it should be
    -Is there an easy way to just infill a solid that is hollow, like a 3D paint bucket tool?
  • any advice on creating perfectly interlocking pieces would also be great .

Thank you in advance!

MakeHole will cut a hole in any solid from a planar closed curve. Just specify a circle hovering over your solid, select MakeHole and specify a cutting depth. Theoretically you should be able to use Boolean Difference as well, but I am regularly having difficulties with that command.


thanks max, Im trying that now, any advice on joining two solids to make one, i.e two cylinders that are slightly different diameters with one inside the other and gap that is between them? Is there a simple way to just fill that gap with a solid so that it is one cylinder with an open centre and no gap between the outer and inner walls?

There are no real “solids” in Rhino, but a polysurface fully enclosing a space without any leaks is labelled that way. So you can make your tube-with-wallthickness in a number of ways. I would create a single tubular surface by extruding a circular curve (do not use the “solid” option), and then use OffsetSrf to create a second surface parallel to the first. This time do use the option “solid”, which will create the end surfaces and join the lot to make a polysurface, your “tube”.

Another way is to create the end annulus first by creating two concentric circles, select both and use the ExtrudeCrv command with the “solid”-option ticked.


Rhino solids are the same as solids in all major CAD programs. The difference is that the UI in most CAD products do not allow “open” solids.