# Subtracting groups **URL:** \ **Category:** SketchUp\ **Created:** [November 9, 2023, 12:56pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662 "2023-11-09T12:56:39Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![TwistedBrain](https://avatars.discourse-cdn.com/v4/letter/t/a88e57/32.png) [@TwistedBrain](https://forums.sketchup.com/u/TwistedBrain)\ **Post date:** [November 9, 2023, 12:56pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/1 "2023-11-09T12:56:39Z")
Hello all, I made a rod cylinder and also as base made from rods. I put the base into the cylinder and try to cut it, so I only have the inner with the slope plus the cylinder around it? Any idea how to do it. Cutting faces don’t work. ![Bildschirmfoto 2023-11-09 um 13.55.33](https://global.discourse-cdn.com/sketchup/original/3X/5/f/5fffcb1b5fa2620b982135304a43c7e2ab2a7ec0.png) _[File is here](https://file.io/wYm1rNChRN4c)_ ---
**Author:** ![DaveR](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/daver/32/7601_2.png) [@DaveR](https://forums.sketchup.com/u/DaveR)\ **Post date:** [November 9, 2023, 1:07pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/2 "2023-11-09T13:07:03Z")
It won’t work to use the vertical tubes to cut the floor because the tubes don’t intersect completely. ![Screenshot - 11_9_2023 , 7_03_11 AM](https://global.discourse-cdn.com/sketchup/original/3X/e/d/ed79377aa6a9ada40d5f8b97a0dc58f327109d11.png) If I were doing something like this I would make a _solid_ object (group/component) of the tubes for the floor and then draw a circle to the inside radius of the cage, extrude that through the floor object, and use the Intersection tool from Solid Tools or from Bool Tools 2 to trim the floor rods to fit. ---
**Author:** ![TwistedBrain](https://avatars.discourse-cdn.com/v4/letter/t/a88e57/32.png) [@TwistedBrain](https://forums.sketchup.com/u/TwistedBrain)\ **Post date:** [November 9, 2023, 1:09pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/3 "2023-11-09T13:09:41Z")
Thank you. That sounds complicated. How should I draw the circle inside the cage with an angle? Or just a circle and then tilt it? ---
**Author:** ![DaveR](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/daver/32/7601_2.png) [@DaveR](https://forums.sketchup.com/u/DaveR)\ **Post date:** [November 9, 2023, 1:11pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/4 "2023-11-09T13:11:07Z")
The circle shouldn’t be at an angle. It should be aligned with the vertical axis of the cage so you wind up with an elliptical floor. I’m making an example. Sit tight. ---
**Author:** ![DaveR](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/daver/32/7601_2.png) [@DaveR](https://forums.sketchup.com/u/DaveR)\ **Post date:** [November 9, 2023, 1:16pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/5 "2023-11-09T13:16:56Z")
From left to right. Floor as a solid object. A cylinder drawn to fit inside the cage. And on the right, the floor after using Intersection. ![Screenshot - 11_9_2023 , 7_14_44 AM](https://global.discourse-cdn.com/sketchup/original/3X/b/4/b47c476d633690654417eddbacdfbaca0bcd3ae0.png) By the way, depending on how close to reality you need to model this thing, you might need to give some thought as to how the floor would be attached to the cage. since the floor rods won’t line up with the vertical rods maybe there needs to be something like a ring welded to the vertical rods for the floor rods to be attached. Don’t be too quick to lose the cylinder because you can use it and a rectangle with Intersect Faces to create a Follow Me path to make a ring for the floor to sit on. ![Screenshot - 11_9_2023 , 7_37_08 AM](https://global.discourse-cdn.com/sketchup/original/3X/f/1/f1d70dc6a0a58eb9c195a902fadea8e16b7baf77.png) Now I want to model a BBQ grill. 🤪 ---
**Author:** ![TwistedBrain](https://avatars.discourse-cdn.com/v4/letter/t/a88e57/32.png) [@TwistedBrain](https://forums.sketchup.com/u/TwistedBrain)\ **Post date:** [November 9, 2023, 1:37pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/6 "2023-11-09T13:37:23Z")
Wow…you are a wizard! I will try to follow your instruction and get back ---
**Author:** ![DaveR](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/daver/32/7601_2.png) [@DaveR](https://forums.sketchup.com/u/DaveR)\ **Post date:** [November 9, 2023, 1:38pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/7 "2023-11-09T13:38:05Z")
Thank you. Let us know how you go. ---
**Author:** ![TwistedBrain](https://avatars.discourse-cdn.com/v4/letter/t/a88e57/32.png) [@TwistedBrain](https://forums.sketchup.com/u/TwistedBrain)\ **Post date:** [November 9, 2023, 1:49pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/8 "2023-11-09T13:49:54Z")
![Bildschirmfoto 2023-11-09 um 14.49.15](https://global.discourse-cdn.com/sketchup/original/3X/5/b/5b4787e55819f113a5da1a6880b1192f35033a2b.png) ![Bildschirmfoto 2023-11-09 um 14.54.14](https://global.discourse-cdn.com/sketchup/original/3X/6/4/643d4446e65df551d624ef9489ddd2e27280117f.png) ![Bildschirmfoto 2023-11-09 um 14.54.20](https://global.discourse-cdn.com/sketchup/original/3X/f/7/f76ddcb6e217d6511b8790bc60e6877a43974420.png) I now have this. But when I cut the two faces and try to erase all the outer parts, it deletes the whole thing?? ---
**Author:** ![DaveR](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/daver/32/7601_2.png) [@DaveR](https://forums.sketchup.com/u/DaveR)\ **Post date:** [November 9, 2023, 1:57pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/9 "2023-11-09T13:57:50Z")
I think you aren’t doing what I directed. Make sure the floor rods are a single group/component and it is shown as solid in Entity Info. ![Screenshot - 11_9_2023 , 7_54_48 AM](https://global.discourse-cdn.com/sketchup/original/3X/5/4/5423810a76981e6ba31117da0d88d1a33ac569f7.png) Draw a cylinder, not a tube and make it a solid object. ![Screenshot - 11_9_2023 , 7_55_42 AM](https://global.discourse-cdn.com/sketchup/original/3X/7/0/70c0200834a5cf73556e20ce1bd96ef641216ed0.png) Then use the Intersect tool from the Solid Tools set. ![Screenshot - 11_9_2023 , 7_56_59 AM](https://global.discourse-cdn.com/sketchup/original/3X/6/1/61c99ac700a15bf064886458f9fef4d1dc6952df.png) Or the same from Bool Tools 2 or Eneroth Solid Tools. to intersect the two objects. ---
**Author:** ![TwistedBrain](https://avatars.discourse-cdn.com/v4/letter/t/a88e57/32.png) [@TwistedBrain](https://forums.sketchup.com/u/TwistedBrain)\ **Post date:** [November 9, 2023, 2:05pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/10 "2023-11-09T14:05:32Z")
I don’t know to make it a solid. Commands said one object is not a solid. My bottom plate. But i don’t know how to make it a solid. I grouped it and made it a component? ---
**Author:** ![DaveR](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/daver/32/7601_2.png) [@DaveR](https://forums.sketchup.com/u/DaveR)\ **Post date:** [November 9, 2023, 2:17pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/11 "2023-11-09T14:17:17Z")
In order to be considered solid a group or component must contain only edges and faces. Every edge must be shared by exactly two faces. So no stray edges, no holes in surfaces, and no internal faces. Solid can only apply to bottom level groups and components. Nested groups/components will not be solid because they contain groups and/or components. If you model one rod as a long cylinder and use Move/Copy to make the rest of them, select them all and create a group or component, the result should be a solid group/component. > [@TwistedBrain](#): > > I grouped it and made it a component? I don’t understand what you mean. Did you make it a group and then convert it to a component or did you make a group and put it inside a component? If the former, there’s no reason to first make it a group if you’re going to then make it a component. Just make it a component from the git go. If the latter, the component won’t be a solid even if the group inside is solid. In that case, explode the top level component leaving just the group. Edit to add: Here’s an illustration of the solid thing. ![Screenshot - 11_9_2023 , 8_31_04 AM](https://global.discourse-cdn.com/sketchup/original/3X/1/3/13eacd7c9dfe6ff4677955b3c83a579b08f6161e.png) ---
**Author:** ![TwistedBrain](https://avatars.discourse-cdn.com/v4/letter/t/a88e57/32.png) [@TwistedBrain](https://forums.sketchup.com/u/TwistedBrain)\ **Post date:** [November 9, 2023, 2:38pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/12 "2023-11-09T14:38:22Z")
Yes! Thanks! My bottom plate is the problem. I don’t get it. I started a new grid. Made one rod and checked if this was a solid. It is! Then I copied this rod along a line. In the end, I made it a component. But then it is not a solid anymore. I don’t know why? I am getting nuts with those solids issues. ---
**Author:** ![DaveR](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/daver/32/7601_2.png) [@DaveR](https://forums.sketchup.com/u/DaveR)\ **Post date:** [November 9, 2023, 2:43pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/13 "2023-11-09T14:43:09Z")
> [@TwistedBrain](#): > > Made one rod and checked if this was a solid. It is! Then I copied this rod along a line. In the end, I made it a component. > But then it is not a solid anymore. This makes it sound as if you’ve created a nested component of the rod group. Try doing it the way I described instead. Draw one cylinder. Do not group the geometry. Copy the cylinder with Move/Copy. Select all of the cylinders and make a group or component. ---
**Author:** ![TwistedBrain](https://avatars.discourse-cdn.com/v4/letter/t/a88e57/32.png) [@TwistedBrain](https://forums.sketchup.com/u/TwistedBrain)\ **Post date:** [November 9, 2023, 2:44pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/14 "2023-11-09T14:44:27Z")
Thank you, I will try that. It is getting frustrating. One mistake and its not a solid anymore. And to find out why nearly impossible. ---
**Author:** ![DaveR](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/daver/32/7601_2.png) [@DaveR](https://forums.sketchup.com/u/DaveR)\ **Post date:** [November 9, 2023, 2:49pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/15 "2023-11-09T14:49:45Z")
Maybe start with something more basic like the box I showed as an example. Think about what I described for what it takes to be a solid and make sure you meet those requirements. You could be using Solid Inspector 2 to help you identify what is preventing an object from being a solid. Here I’ve combined the three main things that prevent an object from being solid. ![Screenshot - 11_9_2023 , 8_48_02 AM](https://global.discourse-cdn.com/sketchup/original/3X/f/c/fccf32bbae2628b0566409b771ac6f91b76a5cb3.png) And here I have a group inside of a component. ![Screenshot - 11_9_2023 , 8_49_22 AM](https://global.discourse-cdn.com/sketchup/original/3X/c/3/c3ce2eff9116b6f655d7fba1deb9a97bb39ba0db.png) ---
**Author:** ![TwistedBrain](https://avatars.discourse-cdn.com/v4/letter/t/a88e57/32.png) [@TwistedBrain](https://forums.sketchup.com/u/TwistedBrain)\ **Post date:** [November 9, 2023, 2:58pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/16 "2023-11-09T14:58:32Z")
Will check out the inspector. I now created 4 bottom grills, but every time it stated not a solid. [Here is the file](https://file.io/C2HaBTWdQAhJ) Thanks for your help. Much appreciated ---
**Author:** ![DaveR](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/daver/32/7601_2.png) [@DaveR](https://forums.sketchup.com/u/DaveR)\ **Post date:** [November 9, 2023, 3:02pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/17 "2023-11-09T15:02:04Z")
You’ve got nesting galore! Look at Outliner. ![Screenshot - 11_9_2023 , 9_00_38 AM](https://global.discourse-cdn.com/sketchup/original/3X/e/0/e06c04bb23d475518ba22da3c79c440bf73fd58b.png) Again, there can be **no nesting**. Just the edges and faces in a single group or component. I’ve exploded all of your groups except the top level. It’s just the edges and faces inside a single group. Look at Outliner here. Entity Info shows it as solid now. ![Screenshot - 11_9_2023 , 9_03_19 AM](https://global.discourse-cdn.com/sketchup/original/3X/8/6/865b9aa754da16841b81d7f183df340d04e7b00a.png) ---
**Author:** ![TwistedBrain](https://avatars.discourse-cdn.com/v4/letter/t/a88e57/32.png) [@TwistedBrain](https://forums.sketchup.com/u/TwistedBrain)\ **Post date:** [November 9, 2023, 3:04pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/18 "2023-11-09T15:04:00Z")
🥶 😥 How can I solve that? I made groups of rods and copy them. I think that is the issue? ---
**Author:** ![DaveR](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/daver/32/7601_2.png) [@DaveR](https://forums.sketchup.com/u/DaveR)\ **Post date:** [November 9, 2023, 3:05pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/19 "2023-11-09T15:05:18Z")
> [@TwistedBrain](#): > > I made groups of rods and copy them. You’re too quick to make groups. Do _exactly_ what I told you to do. > [@DaveR](#): > > Draw one cylinder. Do not group the geometry. Copy the cylinder with Move/Copy. Select all of the cylinders and make a group or component. ---
**Author:** ![TwistedBrain](https://avatars.discourse-cdn.com/v4/letter/t/a88e57/32.png) [@TwistedBrain](https://forums.sketchup.com/u/TwistedBrain)\ **Post date:** [November 9, 2023, 3:07pm UTC](https://forums.sketchup.com/t/subtracting-groups/247662/20 "2023-11-09T15:07:49Z")
Okay, I will do that later. Thank you for your patience. I have to dry my tears first because all my work for nothing. But I am getting closer