Autodesk Inventor, Creating a coordinated BOM for Large Assemblies
I’ve been creating some pretty huge assemblies with Autodesk Inventor lately, and It’s really been bogging my machine down.
This handy workaround has saved me time and frustration when adding Part number Balloons and Parts lists to my large assembly drawings.
This tip was inspired by this post by Eric Small on MCADForums:
In the Joinery Industry we don’t do many ‘Piece Part’ drawings – one stick of wood is pretty much the same as another right! Almost every drawing we create is an assembly drawing, and no drawing is complete without item numbers and a cutting ticket.
Creating a coordinated BOM
Creating a coordinated ‘Bill of Materials’ (or BOM) with Inventor is pretty straight forward. The usual way is to put all your Parts and Sub-assemblies into one ‘Master’ Assembly. The BOM is created from this ‘Top level’ or ‘Parent’ Assembly, which in turn is used to create the parts list (or in our case – the Cutting Ticket).
Large Assembly management
However this can create some pretty large assemblies which in turn can place a massive load on your computer, increasing file load times and making drawings pretty unwieldy.
Autodesk Inventor’s ‘LOD’s’ (Level of details) are a great tool for managing large Assemblies. The trouble is that, even if you have created your drawings from your carefully constructed LOD’s, as soon as you place an Item Balloon on your drawings Inventor will immediately load in all the parts that you had filtered out with your LOD!
A Large Assembly BOM Workaround
The trick here is to ‘Push’ the item numbers from the Coordinated BOM down to the part level, and it’s pretty simple when you know how!
We will work through the following steps:
- Create Parts and Assemblies as usual
- Name, sort and arrange Master BOM
- Number Parts
- Create a Custom Parts Field
- Copy the Item numbers into your Custom Field
Creating The Master BOM
Begin by creating your parts and assemblies as usual. Place all your components into your Master assembly and fire up the BOM manager.
Assemble Tab > Manage Panel > Bill of Materials
In this example I am using the ‘Parts Only’ representation in the BOM. Follow your usual steps of naming, arranging and sorting the BOM to your satisfaction. Now comes the trick – create a custom iProperty Field and copy and paste your item numbers into it.
Creating A Custom iProperty Field
To create a custom iProperty Field in your Bill of Materials, click on the ‘Add Custom iProperty Columns’ Button in the BOM manager.
In this example I will call our custom iProperty field #ITEM To distinguish it from the standard ‘Item’ Number column.
Tip: Make your custom name something you will remember – we will need it later.
You may need to use the ‘Choose Columns’ button to add your new iProperty column to the BOM manager.
Simply drag and drop your custom column into place in the BOM manager.
Copying the BOM item numbers into the Individual Parts
Now Highlight the Item numbers from your perfectly organised BOM, right click and chose copy…
..and the paste the Item Numbers into the #ITEM Numbers column.
When you save your master assembly the custom field will be written into every part file in your assembly.
You can now create drawing views of single part files and sub assemblies, confident that you can reference this coordinated part number directly from the component.
Creating a custom Item Number Balloon
The final step is to create a copy of your Balloon style that uses your new Custom Item Number field. Create a new drawing and fire up the Styles and Standards manager.
Manage Tab > Styles and Standards Panel > Styles Editor
Right Click on the Balloon style you want to copy and chose ‘New Style’.
The new style will be a copy of the style you picked. In the Pop up box that follows name your new style. I’ve called this one ‘Balloon (ISO) #ITEM’ to remind us of our Custom Field.
In the Balloon style Dialogue – click on the ‘Property Chooser’ Button.
In the Property Chooser Dialogue, click on ‘New Property’.
In the ‘Define New Property’ Dialogue add the name of custom Field – ‘#ITEM’
(I told you that we would need to remember it later!)
Back in the Property Chooser Dialogue, our new Field will have been added to the selected properties list box.
Use the ‘Move Down’ and ‘Move Up’ buttons to re order the list, and the ‘<-Remove’ button to remove the old ‘ITEM’ value that we don’t need any more.
When you return to the Balloon style Dialogue the ‘#ITEM’ value should be shown in the ‘Balloon Formatting Box’.
Close and save the new addition to your Style.
Tip: We have created this new style Locally, don’t forget to save it back to your company standard if you want to share it with others.
Using your new #ITEM Number Balloon Style
To use your new Balloon style click:
Annotate Tab > Table Panel > ‘Balloon’
Tip: Don’t forget to chose the correct Balloon style from the ‘Format’ Tab before you place your Balloons!
A Coordinated BOM from Part, Subassembly and Assembly Files!
You can see from this screen shot of the drawing browser tree that I have created this drawing from a Part, a Subassembly and the main Assembly.
And the parts list is coordinated across them all!
Obviously, this is not a good technique if you are using some of your parts in multiple assemblies, and if your PC is powerful enough to manage your assemblies without resorting to this work around then that’s great!
However, if like me, you have ideas above your station – then this is a good workaround to know about :)
Thanks very much to Eric Small and the crew on MCADforums and the Autodesk Discussion groups. Click on the links to join in the discussion.
Read ‘Assembly techniques for Woodworkers’ for more on dealing with Large Assemblies.