In SolidWorks, it use to be that all geometry in a part had to be one body. Then we got the ability to create multiple bodies in a part with only one material. Now, by a stroke of genius, SolidWorks has bequeathed upon you the ability to add multiple materials to multibody parts. We’ll explain how to do it, how it’s different from regular parts and what’s shakin’ out in beta.
Why Create Multibody Parts instead of Assemblies?
Originally, multibodies in parts were intended for welded materials – angles and such that are all common in material type and density. However, as laziness ensued and people, like myself, used parts to create quick ‘assemblies’ of similar materials, it became clear there was some power behind multibody parts. The only thing missing? Multiple materials.
Multibody parts can make layouts go quicker. You’re working in a single part file rather than an assembly with multiple parts. You don’t have to worry about circular references or a file missing either. For assemblies that use the same or similar materials it can be a big time saver. You’ll still have the potential for missing relations and making modifications can be more difficult since you’re working with a history tree of features rather than a stack of part files.
Quick Intro to Multibody Parts
If you know how to create multibody parts, skip to the next part. Basically, each separate contour you create withsketches in a part is a body. Now you can apply a material to each of those bodies. In the example below, you’ll notice there’s only one feature (Boss-Extrude1) in the FeatureManager tree. Above, you will see a Solid Bodies(2) folder. This shows you how many bodies are in the part.
To create bodies, you can either create multiple contours in one sketch or you can create multiple features and de-select Merge Results when you extrude the sketch.
How to Add Different Materials to Different Bodies
If you use the SolidWorks Material Database to add materials to regular parts, it’s done exactly the same way for bodies. The only difference is that you’re selecting the body instead of the part. Here’s how to do it.
- Expand the Solid Bodies folder
- Right-click on a Body
- Select Material, Edit Material
Apply Same Material to More than one Body
You can apply materials to multiple bodies by holding down Ctrl, selecting the bodies and editing the material as above.
Create your own material database
You can add to the Custom Material Database or copy the SolidWorks Material Database (solidworks materials.sldmat located in C:Program FilesSolidWorks CorpSolidWorkslangenglishsldmaterials) and modify it as required.
Material Properties for Multibody Parts
Note: In SolidWorks 2010 Beta 2/3 the material will not appear in the Custom Properties or in a Drawing BOM (a Cut List). When the issue is resolved the post will be updated.
Setting up Material Properties for Multibodies is a bit more of a process. To keep it simple, just follow these steps:
- Turn the Solid Bodies into a Cut List by Inserting a Weldment Feature (Insert, Weldments, Weldment…)
- Right-click on Cut list in the FeatureManager and select Update
- Right-click on a Cut-List-Item and select Properties…
Now you can add Custom Properties as you would for a part. For Material, Enter the Property Name and select Material from the Value/Text Expression pull-down.
What about automating Custom Properties for Multibodies?
Many companies have automated ways of assigning Custom Properties, including materials, to Parts via the SolidWorks API. I have yet to find a way to automate Custom Properties into Multibodies without saving the bodies out as separate parts. For the time being, Custom Properties for Bodies will need to be assigned as mentioned above.
Are Multibodies Better?
While it’s incredibly nice to have the ability to set materials on separate Bodies, there’s a bit of functionality still missing. For one, you need to be able to show the material in the Cut List. As I mention above, this should be resolved in Beta. Creating custom properties for multibodies isn’t as simple as it is for parts. But hey, we have materials for bodies now. But, since we have this, the idea of ‘Weldments’ needs to just go away, or at least be moved. The addition of material for multibodies opens up a lot more applications beyond just using them for welded parts. Removing the requirement to turn them into Weldments to have a BOM created would make product design in a part file much easier.
Getting past all that, multibody parts can be used to quickly lay out a design in a single part file. You still need to have a method for how you lay it out – how it will work in an assembly, how each body relates to the other. If you have a product that uses a lot of stock material in product design, I’d give multibodies a go and see how it works for your process.
