BOM Structure Overrides in Assembly

[jmfowler1996]

Consider this situation:

You make a drawing for an assembly, e.g:

You then want to do a separate drawing for an additional component. You want to show how it fits on the main assembly, so you show it as a reference:

The problem here, is that by changing the BOM structure of the main assembly for the second drawing, you automatically change it in the first drawing too. You can't have both drawings at the same time with different BOM structures.

Also, if you were to make an assembly drawing showing lots of components in the assembly, It would affect the views as well as the bill of materials. You might want to show the main assembly in the BOM of some drawings, but not others.

I think it would be helpful if you could have the BOM structure of a part/assembly overridable so that different assemblies can have different BOM structures for the same components.

[kennyjohnson1]

I'm not sure I'm clear on this.

You have your first assembly (the three blocks).

You create a new assembly, insert the first assembly and change it to be a BOM - Reference.  This does not change the original assembly; but on the second assembly it now shows up phantom/uncolored.  You add your new parts to this second assembly.

So for each change of reference, you just need to create a new assembly; for example if you wanted to add new parts to your 2nd assembly, (IE you are building the Block Direction Booklet) you would create Assembly 3, and insert the 2nd Assembly in, change it to Reference, then add your new parts.  Using this method also allows you to pick & choose what is reference; so if you wanted the original 3 parts to not be reference, just insert the first assembly and don't change the BOM.

Consider also, if you are looking at color / rendering results, using the View Reps might be a better option than using BOM - Reference.  You can set up each step / transition to have the previously added items change color/material to fade or wash out.

Hope this helps,

Kenny

[jmfowler1996]

 Actually, what Kennyj says would work.

I thought deriving assemblies would cause problems with the colours:

But looking again, there is actually an option when deriving the assembly which allows you to keep the colour details.

Thanks Kennyj.

[DRoam]

@jmfowler1996, you actually can override BOM structure. In your assembly showing where to put on the little round pieces, right-click the three-brick sub-assembly and click iProperties --> Occurrence tab. Here you can change the BOM structure for just that occurrence to Reference. Everywhere else will keep the Default BOM structure as specified in the Document Settings for the three-brick assembly.

There could be a lot of improvements to this system, though. Please read this discussion and vote for any of the ideas I mentioned there that you think would be helpful: Allow setting of BOM structure from iProperties.

[DRoam]

Also, a quick tip regarding the Derive method (even though you don't need to use it now): in your latest picture you can see that the red color from the red brick bled over onto the side of the white brick. This is because Inventor fused those two co-planar faces into a single face, so it had to pick one of the colors and apply it to the whole face, and it picked red.

You can fix this by choosing the Derive style of "Solid body keep seams between planar faces" rather than "Single solid body merging out seams between planar faces" from the Derived Assembly dialog. This will keep the seam between the two faces and allow both bricks to keep their color. Just a tip in case you do ever need to use the Derive method.

EDIT: You could also opt for the "Maintain each solid as a solid body option" which would give you Visibility control over each body/Part, which might be handy.

[jmfowler1996]

@DRoam

Thanks! That should be really handy. I didn't like the idea of having to create extra files just for particular views. Also, it would be a real pain trying to fix existing views by replacing existing components in an assembly with a derived part and re-constraining everything.

I'll have a look into this.