Materials and Weight
Weight comes from the volume of each body and the density of its material. Set a material for each body, then read the total with Mass on the Measure tab.
Step by Step
- Right-click a body in Model, Solid Bodies, and choose Material.... See Model Tree: Material.
- Pick the material and click Set.
- Open the Measure tab, click Advanced and then Mass.
- Click the model. The weight is written at its center, in pounds.
Which Material Is Used
For each body the viewer takes the first of these:
- The material you picked for that body.
- A material the opened file names, when the viewer knows it. If the file gives a material the viewer does not know, it is used with the file's own density when the file has one.
- The default material, which is Carbon steel.
The Materials
Densities are in pounds per cubic inch.
| Group | Material | Density |
|---|---|---|
| Metal | Carbon steel | 0.284 |
| Metal | Stainless 304 | 0.289 |
| Metal | Stainless 316 | 0.290 |
| Metal | Aluminum 6061 | 0.0975 |
| Metal | Brass | 0.307 |
| Metal | Cast iron | 0.260 |
| Metal | Titanium | 0.160 |
| Metal | Copper | 0.323 |
| Wood | Pine | 0.01535 |
| Wood | Douglas fir | 0.01915 |
| Wood | Maple | 0.02475 |
| Wood | Red oak | 0.02673 |
| Wood | White oak | 0.02782 |
| Wood | Walnut | 0.02421 |
| Wood | Birch plywood | 0.02457 |
| Wood | MDF | 0.02710 |
| Plastic (3D print) | PLA | 0.04480 |
| Plastic (3D print) | PETG | 0.04588 |
| Plastic (3D print) | ABS | 0.03757 |
| Plastic (3D print) | ASA | 0.03866 |
| Plastic (3D print) | Nylon | 0.04119 |
| Plastic (3D print) | TPU (flexible) | 0.04371 |
| Plastic (3D print) | Polycarbonate | 0.04335 |
| Plastic (3D print) | Resin (SLA) | 0.03974 |
Wood densities are typical air-dried values. Plastics are typical printed values. Your actual material may differ a little, so treat the weight as an estimate.
How the Total Is Worked Out
Each body's volume is multiplied by its material's density, and the results are added. The readout then says:
- The material name, when every body uses the same one.
- mixed materials, when they differ.
- A list of bodies "not counted, no density in the file", when a body has no density. If no body has a density, the result reads "unknown".
Material From the File
Some STEP files carry a material name. When the viewer knows the name, it is used for the weight until you pick a body's material yourself. Your pick always wins. Check each body's note in Solid Bodies if the total looks off.
Center of Mass and Inertia
The same densities give the center of mass and moments of inertia in Mass Properties (the Mass Properties button on the Measure tab).
Tips
- Rename a body and its material follows the new name.
- Changing a material updates the weight at once.
- Only bodies that are showing are weighed. Hidden bodies are left out.
- Weight is always shown in pounds, whatever length unit you use.
If Something Goes Wrong
- "Weight needs a 3D model." The Mass button is grayed on a flat drawing.
- The weight is for steel but the part is aluminum. Set the body's material.
- A body is "not counted". It has no density. Give it a material.