# Subtracting groups

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.

File is here

It won’t work to use the vertical tubes to cut the floor because the tubes don’t intersect completely.

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.

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?

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.

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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.

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.

Now I want to model a BBQ grill.

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Wow…you are a wizard! I will try to follow your instruction and get back

Thank you.

Let us know how you go.

I now have this. But when I cut the two faces and try to erase all the outer parts, it deletes the whole thing??

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.

Draw a cylinder, not a tube and make it a solid object.

Then use the Intersect tool from the Solid Tools set.

Or the same from Bool Tools 2 or Eneroth Solid Tools. to intersect the two objects.

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?

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.

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.

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.

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.

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.

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.

And here I have a group inside of a component.

Will check out the inspector. I now created 4 bottom grills, but every time it stated not a solid.

Here is the file

Thanks for your help. Much appreciated

You’ve got nesting galore! Look at Outliner.

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.

How can I solve that? I made groups of rods and copy them. I think that is the issue?

You’re too quick to make groups. Do exactly what I told you to do.

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