Help Intersecting Cylinders

I am trying to create a sort of pipe fitting. I drew the main cylinder here, then drew the four smaller cylinders off to the side. I then moved the smaller cylinders into the larger cylinder, and want to clean up the extra material. I’ve tried intersecting with model and intersecting with selection, but neither seems to allow me to go in and delete the extra material.

test part new.skp (1.2 MB)

Are you using SketchUp Pro? If so, you can use the Solid Tools commands to join them together.

If not, you are on the right path using intersect. Unfortunately, you will have to look inside the pies and delete the “extra” geometry manually. You can do this either by turning on on Xray mode and using the Eraser command to pick the lines that you want to remove, or Hide the end wall of the main cylinder, and user erase to remove the geometry from the inside.

Hope that makes sense!

1 Like

Or you can use a section cut to have a nice view inside…

Edit: little animation


In order to do what you want, you need to do two things. First, you need to have all of the short tubes in the same context as the long tube. They are currently wrapped up in separate components. The edges and faces all need to be within the same component wrapper. The easiest thing to do is explode both components and select everything to make a new component.

Due to the very small size, you’ll have some issues so you need to work on the thing at a larger scale. My preferred method for this would be to make the component as I described, make a copy of the component and scale that copy up by a factor of 100 or even 1000. Open that component for editing and do the intersections and erasures to get the thing looking the way you want it. Then close the component to get out of Edit mode. delete the large copy and return to the original which will be sitting where you left it at the correct size.


I generally avoid unnecessary or arbitrary grouping of objects for no particular reason, especially when these objects are intended to form one, integral “part”. If the only reason for grouping objects is to avoid having them stick together while you maneuver them into position to assemble or merge them, take that as a cue that you should be brushing up your skills with the Move tool. There’s no good reason to get things all stuck together if you plan your moves in advance: if you don’t have a particular strategy for a move, i.e., the point where where you grab an object and the target where you’re going to snap it, don’t even bother with the move. Grouping a bunch of geometry only to explode it a few seconds later doesn’t make much sense either.

You know, since this part, a manifold, consists of repetitive geometry, you might consider modeling one tee element and then using an array (of copies) to create the manifold itself. No real point in modeling the intersection between the run and the branch more than once, since that is the most laborious part of the procedure.


1 Like

So many options!!!

1 Like

Thanks all! No SketchUp Pro for me, but it looks like I have some options nonetheless.