Circles on cyclinders

Question: Can I add a cylinder to an existing cylinder.
When I draw a circle to an existing cylinder the circle does not form to the shape.
See the attached image. I’m currently using SketchUp Pro 2016

I’m using SketchUp Pro 2016.

A circle is a planar object that will never conform to the curved side of a cylinder. But if what you really want is a second cylinder sprouting from the side of the first, do this:

  • draw the circle as per your figure
  • push-pull it away from the first cylinder to form the second cylinder
  • move the new cylinder in until it pierces the first one
  • use intersect faces with to create edges where the two cyls cross
  • delete the extra geometry inside the cylinders

Here is a quick GIF of what @slbaumgartner explained (I am a visual learner)

The only thing missing is deleting the additional geometry on the inside of the pipe.


Very cool Aron.


After I compete this action I cannot push/pull the circle.
Alert: Can’t push/pull on curved or smoothed surfaces.

That is correct. These steps will give you a circle on the side of a cylinder. Once there, it cannot be push/pulled.

I am assuming that you are looking for a different final geometry. Can you explain what you are hoping to create, then maybe I or someone else on the forum can let you know how to model what you need?

Correctly speaking, the shape on the side of your cylinder is not a “circle”. It is a 3D curved surface whereas a circle is planar. Pushpull extrudes a planar face along the face’s normal (perpendicular). What direction is perpendicular to that curved shape? So, as @TheOnlyAaron observes, please tell us what geometry you want to end up with.

Here’s a guess: if you want another cylinder projecting from the side of the original, just follow the steps described earlier, but don’t erase the part of the new cylinder sticking out of the original.

1 Like

Thanks for everyones input and help.
I think I’m rolling.


thanks TheOnlyAaron it worked great for me

Aron- What view are you working in for this tutorial.
When I draw a circle to the side of my cylinder it lies flat on the red axis.


Can you post another screenshot? I’m not sure what you mean… I was in an isometric perspective view.

I’ll refer you back to my previous answer to this question.

An oxymoron.


Here is an example of how to use positional inferencing to achieve what you want. I would normally move around even more than this but I’ve kept it to a minimum as the more you move the larger the gif file becomes.


Dang! Your right…

How’s this; “Perspective camera in a off-axis view”?

Probably just “perspective” would do. The whole point, I think, is that a perspective view is not constrained to any fixed orientation as are orthographic and conventional pictorial (e.g., isometric, dimetric, trimetric, oblique) views. With a perspective view, you can just wheel around until you can see what you’re looking at. A hundred alternative views–off by a degree or two–would do as well. I find it odd how difficult or counter-intuitive some new users seem to feel working in perspective is, considering that’s how they’ve been looking at the world their whole lives.


Tangential question: Box, what is that toolbar at the top of your animation? Is it custom, and if so, how does one make a custom toolbar in SketchUp?