Joining two complex (rounded) objects?



Hello. I’m very new to SketchUp (3 days?) but was able to search and use Help to solve most of my issues. I’ve run into a problem in trying to create a support pillar for a tube running through my model. I was able to successfully create (and union) the tube and the frame, but I’m going in circles now. I cannot figure out how to join this support strut to my complex/rounded tube.

Worse yet, I’ve now made what was a working, solid object, no longer solid. Which is pretty much the bane of my existence. It’s been 2 steps forward and 5 back.

Any help/advice in finishing this last part would be greatly appreciated!
vaportubev2.skp (1.5 MB)


At this point you could select the geometry where the tube and the frame meet, right click on it and choose Intersect Faces>With Selection. Then you could erase what you don’t want to keep.

I think I’d have been inclined to leave that bent tube as a separate component but it depends on what you plan to do with this thing once you have the model complete.

Is the tube on the top supposed to be centered on the larger cylinder?

One thing you’ve done that will create issues is you haven’t been consistent in dragging out the radii of your circles. This creates issues when vertices aren’t aligned. It’s always best when drawing circles to drag the radii out on axis.


Ideally, yes, but aligning objects in SketchUp has been an issue for me. It doesn’t need to be centered but I’ve been doing the best I can by aligning to the various axis and by eye/hand. I’m finding the UI a bit…challenging…as a n00b.

I’ll try your recommendation re: Intersect Faces and report back.

Model is in mm x10. Previous searches indicated to build big and then scale down.


Would you want to look at it together?


I agree with @DaveR that you could keep more of the parts as separate components.

And nothing is exactly centred or exactly on axis, as Dave has also just commented - is that deliberate?

Your dimensions don’t seem to be whole numbers in either inches or mm. Are they intended to be?

I’d start again, I think, making the larger tube first as a separate component diam 8", the straight upper tube OD 2" also as a separate component, and the bent tube made again as a separate component using FollowMe. Add the ring and cross piece to hold the bent tube.

Then intersect to get the penetration of the bent tube through the walls of the larger cylinder.

Dave, shall I leave this one to you from here?


@DaveR that let me eliminate the intersecting piece inside the tube (progress!) but not the other pieces. The entire plane gets removed.

I really don’t want to start over on my 3rd try…everything was working awesome until I got to the support strut and then just chaos and frustration. But if that’s the recommendation I can.

@john_mcclenahan the bent tube was made as you described and, as you can see, I was able to handle that first intersection with the main cylinder without issues. I guess I need to go back to SketchUp 101 re: components and groups?

For nearly everything I’ve been using (typing in) my measurements in mm x10. So if they’re weird you may not have the right scale set? Should I be working in 1:1 full scale and not blown up by a factor of ten?


Does this look reasonably close to what you’re trying to achieve?

I get that but there are problems related to the way you’ve drawn circles off axis. That’s part of the reason things have gone pear shaped. Starting over would be a whole lot easier than repairing the model as it is.

That’s not a bad thing to do. Personally I would start the model at the size I want it to be. I would make components of parts of the model and then use the Dave Method before doing things that might create tiny faces that would cause problems.


As usual, @DaveR gets there first and most helpfully.

In parallel with his post, I was redrawing your model. I thought the dimensions were (nearly) whole inches for outside diameters, with wall thickness of 0.5in, so drew it that way.

As Dave says, it really IS easier to redraw than to modify, and make components as you go, before doing the intersections.

The only thing I’d add to what Dave has already said is to get and use the Trim and Keep plugin (from the Sketchucation Plugin Store), which doesn’t destroy your original components, and keeps the names, when you intersect them (or rather, choose first a Trim component to use as your cutter, then the second component to be kept, less the intersection(s) with the first).

I find it much easier to use than the Solid Tools, or the Intersect Faces command.


I used Trim and Keep to create the hole in the cylinder for the bent tube and to cut the openings on either side of the support inside. Eneroth’s Solid Tools or BoolTools2 would be other good options.


Yes, @DaveR that’s essentially it. Honestly, I’m not sure how/why items would be off-axis as I emphasized keeping everything on an axis when I created it. There a resource to point me towards to ensure I don’t do this again?

I’ll look into Trim & Keep as well as how Components work vs Grouping and start over.

Thank you.


I’m not sure how you got things off center. Inferencing should help you keep things centered. But once you get one thing off center, it’s easy to be inferencing off the wrong center.

When I drew this, I set up everything so it’s centered on the origin. I drew a profile for the cylinder and used a circle for Follow Me. That’s one component. There’s a centerline path and profile for the bent tube and that is another component.

To cut the D-shaped holes on either side of the internal tube support, I made some “cutter solids” which I also used with Trim and Keep on the solid cylinder.


Okay, I think I’ve muddled my way through it. One very useful piece was seeing how @DaveR approached it by using the profile and Follow Me for a seamless object. Mine was more a merging of multiple rough elements which caused problems. So this is much more elegant.

I tried again, paying closer attention to staying oriented on origin so, hopefully, this is a lot better. I stuck with the default mm scale to keep it easy.

Having already done the bent internal tube and merging it with my previous models I think I can do that again without issue. Right now my problem is cutting out the D-shaped holes. I’m not really sure how to approach that.

But here’s where I am right now and, hopefully, I’m on the right track?

Thanks for the help and advice so far!
vaportubev3.skp (1.2 MB)


I’ll look at your latest file shortly.

For the D-shaped holes, I created the “cutters”, which are solids and then used them to trim the cylinder.

I’m glad you fixed the line about the default mm scale. :wink:


OK. The very next step should be to delete the face skinning the bottom of the cylinder and then correct the face orientation. Select all of the geometry, right click on it and choose Reverse Faces. You want white front faces out, not the blue back faces. Then make it a component. That will protect the geometry from other things you need to do like drawing the D-shaped cutters and the bent tube. When you create the component, look at Entity Info to see that it shows as solid.


Okay, think I’m down to the final stretch. I’m messing with the cutters to do the interior frame. I realize in this version that I have not merged the tube with the main cylinder yet…but that’s the one thing I think I figured out last time on my own using Union and manually connecting some interior vertices. I’ve never used a cutting figure like this before to “edit” out the parts I need so fingers crossed.

Scale is 100s of mm, or x10 the size I need…I’ll be scaling the whole thing down when I’m finished. Hopefully no deal-breakers spotted?vaportubev5.skp (1.4 MB)


Before you worry about cutting the interior frame, make sure you deal with the geometry at the bottom edge of the cylinder. There actually edge of the cylinder is slightly smaller in diameter than the rim there. It’s hard to see and maintain context in a screen shot.

You’ll need to run Intersect Faces on the bottom part of the cylinder and erase the outer edges. Zoom in close on your model and you’ll see what I’m referring to. After that, when you make it a group, it should be solid.

As long as the D-shaped cutters are solid and the cylinder is, too, you shouldn’t have any problems.

Just make sure when you scale it down, you keep it close to the model origin. Since the model is centered on the blue axis, this won’t be a problem. If you’d used the Dave Method from the beginning, you wouldn’t need to worry about scaling down.