SolidWorks can automatically flatten sheet metal parts, greatly facilitating fabrication, blanking, and bending processes. However, what should you do if the flattened pattern generated by SolidWorks differs from the actual result or if bending dimensions are inaccurate? Often, the issue stems from incorrect sheet metal bending parameter settings. Today, I will explain how to correctly configure these parameters.
SolidWorks offers five options for sheet metal bending parameters: Bend Table, K-Factor, Bend Allowance, Bend Deduction, and Bend Calculation. Today, we will focus on the three most common and practical parameters.
[Image]
1. SolidWorks Sheet Metal Bending Parameters
"Bend Deduction" is the most frequently used parameter for modeling sheet metal bends. The Bend Deduction value corresponds to the actual bending factor used in practice-such as 1.7 times the sheet metal thickness or a specific value from a manufacturer's bend table. For instance, if a sheet metal shop calculates the deduction by subtracting 0.8 times the thickness from one flange length, you would set the value here to double that amount (i.e., 1.6 times the thickness). Essentially, the Bend Deduction here represents the value subtracted for a 90-degree bend.
[Image]
2. Example: Bend Deduction for 1mm Sheet Metal
For example, as shown in the image above, the Bend Deduction for a 1mm sheet metal bend should be set to 1.6mm.
Bend Deduction is primarily used for 90-degree bends; it is not suitable for bends with large radii or angles other than 90 degrees. As previously mentioned, for large-radius bends, the neutral axis lies at half the sheet metal thickness. In this case, the K-Factor can be set to 0.5.
[Image]
3. K-Factor for Large-Radius Sheet Metal Bends in SolidWorks
It is not advisable to set a global K-Factor for large-radius bends, as not every bend in the part will have a large radius. Instead, you can edit the bending parameters for a specific feature. For example, in the "Edge-Flange1" feature, uncheck the "Use default radius" box. Change the bend radius to 20mm, check the "Custom bend allowance" box, and set the K-Factor to 0.5. Once the software automatically flattens the part, the result will match manual calculations. For non-90-degree sheet metal bends, it is also recommended to set a custom bend allowance. For example, if the software's default setting yields a value of 0.1 mm, modifying the table data results in an automatically calculated K-factor of 0.2183. Once these parameters are configured in the software, the part can be automatically flattened.
Image
4. K-factor for non-90-degree bends
Image
5. Setting the K-factor for non-90-degree bends in SolidWorks
When designing sheet metal hems, using "Bend Deduction" or "K-factor" to calculate the flat length may not yield the desired values. In this case, the "Bend Allowance" method can be used. In the software, the Bend Allowance calculation method is the inverse of Bend Deduction; it uses the straight bend length plus the bend allowance.
6. Sheet metal hem settings
With a sheet metal length of 100 and a hem length of 10, using a default bend deduction of 1.6 results in a yellow warning after flattening.
Image
7. SolidWorks hem flattening
The flattened length is not the required 109.5; here, the bend allowance can be set to: 1 + 1 + 0.1 - 0.5 = 1.6.
Image
8. How to use Bend Allowance in SolidWorks
Look-the flattened length is now 109.5. What is the calculation principle behind the bend allowance of 1.6? "1" represents the sheet metal thickness, "0.1" is the software's default gap (a fixed value), and "0.5" is the bend allowance value for a hem (or "flattened" bend) in actual production.
Recommended Video
Follow the Metalworking Video Channel-an industrial media outlet with a distinct perspective.
