Why Do I Have Two Instances Of This Component?


Please can anyone look at my model and tell me why I have two instances of the component: “4x4 Lintel D-R” in my inventory? If I delete either one, the system warns me that all instances of that component will be deleted (of which there are x2). How can SketchUp be using both components at once to create one instance? I don’t understand and it’s bugging me. I want my component window to be streamlined and meaningful at all times. Maybe not so important here and now - but not understanding why this is happening here, could end up confusing the hell out of me and costing time in a more complex model down the line.Shedbuild 2020~~.skp (2.3 MB)

Many thanks in advance.


You have two instances of this component, one on the ‘left’ of the model, one on the ‘right’ in the view that opens when I open the file.

The component has an extra and unnecessary ‘wrapper’ around another level of component - “Component#1”. You should explode Component#1. But it makes no real difference to what you describe.

If I highlight one of the components in the drawing (or in the Outliner) and press the Delete key, or use the Eraser tool, I only delete the selected instance - exactly as I would expect.

I think that what you are doing is using the Component window with the component 4x4 Lintel D-R highlighted, then using the R-click menu there to select Delete.

That is deleting the Component Definition, not just one of the two Component Instances in the model, so all instances will be deleted if the Definition is deleted.

Does that clarify things for you?

1 Like

No, it has clarified nothing and makes absolutely no sense - but I do not wish to sound ungrateful. I did what you said - clicked on ‘explode’ for one of them and everything is exactly how it should be (how I intended). So thank you very much - you’ve solved my probem, even though I have no idea how. What is the ‘explode’ command for? (Not to worry, I’ll look it up - cheers!)

How can I avoid this problem occuring again?

Again - many thanks!

There are two instances of the component in your model. They are shown selected.

There’s nothing wrong with that. In fact that sort of thing is good. It’s two instances of one component definition.

If you are deleting the component from the In Model component library, you’ll get the message you indicated. If you want to keep the component, don’t delete it from there.

As John said, your 4x4"Lintel D-R component is nested. It contains a component called Component#1. Think of creating a component as putting a transparent wrapper around some stuff. In this case the Component#1 wrapper contains the edges and faces you see as the 4x4 and that component is wrapped up again in the 4x4"… wrapper. There’s no benefit to double wrapping like that. By following John’s instructions, you discarded the Component#1 wrapper.

If you want to keep your Components window streamlined, avoid things like unneeded nesting. After you’ve removed any unneeded nests, go to the Components window, click on the Details menu and choose Purge Unused.

The component called Constructional Aid Brace 1 is nested the same way as is the one called Wood bolt…

Think of a Component Definition as a master pattern, or cookie cutter, and Component Instance(s) as one or more cookies whose shape is defined and cut out by that cutter.

When you first create a Component, you in effect do two things at once: you define the cookie cutter, which is saved in the Component Tray as a Component Definition, AND at the same time, you cut one cookie, which you display in your model wherever you have placed or created it.

When you then copy the instance in the model, or drag out the component from the Component Tray, you are creating another component instance (or cookie) from the same component definition (or cookie cutter).

But if you Delete the Component Definition (or cookie cutter) from the Component Tray, it removes ALL the component instances made by that cutter - they can’t exist any more without the definition of the pattern.

Does THAT analogy help any better? Throw away one cookie (delete one instance) and all the remaining cookies of that pattern remain, unaffected. Throw away the cookie cutter (delete the definition from the Component Tray) and you can’t have those components anywhere in the model any more, or make any more of that shape of cookie.

To avoid having the problem again, DON’T delete a component definition from the Components Tray while you still have any of those components that you want to keep in the model. Just delete any unwanted Instances in the model.

Then from time to time, do as DaveR suggests: run the Purge command from the Component Tray (click on the broad arrow at the right, above the list of component definitions in the model.) That will remove any definitions that are not currently being used.

I’ve just realised that neither DaveR nor I quite gave a direct answer to the question in your topic title: “Why do I have two instances of this component?”

Because you created two, is the answer - one on the left, one on the right, of the shed. You either copied one to the location of the other, or dragged a second copy out from the Component Tray, and placed it at the other end of the shed from the first one.