Set Up Adobe Illustrator file for Metal Bending

Table of Contents

In this tutorial, we’ll look at how to set up your Adobe Illustrator file for metal bending with SendCutSend. It is important to note that a 3D file of your design may be included for reference, but you should not upload a 3D file to the SendCutSend app when you upload the 2D pattern with your bend lines. 

Before you start

To start, download the demo file here and open it in Adobe Illustrator. I’ve designed this metal glove box holder that is bent from sheet metal. You’ll see that I’ve finished the flat pattern with all flanges included. It’s important to note the minimum and maximum flange length. Each flange length must be at least half an inch (.500″) or 4x the material thickness, whichever is greater. 

1. Create bend lines

We’ll need to create lines at each flange that needs to be bent. Zoom in on one flange and activate the Line Segment tool from the Tool Panel. You’ll find it nested with the Rectangle tool by clicking and holding on the rectangle icon. We can then create straight lines for each flange that requires bending. 

Use the line segment tool to create your bend lines

Switch to the “Selection Tool” with the shortcut letter “V” to manipulate the length and position of the lines. You can also hold the shift key which will help you extend the lines without reorienting them. 

To quickly recreate additional lines of the same size, hold down “Option” on Mac or “Alt” on Windows, in addition to the Shift key. This will allow you to duplicate the line segments while keeping them on the same axis.

2. Color your lines

Before uploading to SendCutSend, each bend line will need to be a unique color different from the rest of your design. However, we can use the same color for each group of bends that will head in the same direction with the same angle. For example, select the outer two bend lines in the demo file. You can then double-click on the Stroke color and select a new color. The color itself does not matter as long as it’s not the same as the outer contour. Repeat this process for the remaining two pairs of lines, making each pair have a unique color. 

Use colors to differentiate between bend directions and angles

The lines can remain a solid line; however, you may find it helpful to turn the line into a dashed line. Simply select the Stroke option in the Appearance pane, and turn on the “Dashed Line” option. This is by no means required but may help you visually keep track of bend lines and contour lines, particularly with complex parts. 

The Bend lines should not be placed on a separate layer in Illustrator. The entire flat pattern, including the bend lines, should be on a single layer. 

3. Move lines away from the base

Lastly, I also want to move the bend lines away from the base to help avoid tearing in the corners. In Illustrator, you can precisely move lines by first selecting the desired lines and shift-click multiple lines to move more than one at the same time. You can then type out exact dimensions in the Transform section of the Properties pane

For example, I’d like to move the top two bend lines in the glove box holder up .05 inches. Adobe Illustrator allows us to type out equations directly in the input fields. I can type out the minus symbol, followed .05 inches, and the enter key. If you’re following along, you’ll notice how the lines precisely moved based on values we input. This approach makes it much easier to be precise when compared to manually dragging lines around. 

Keep in mind that you can use the addition symbol to move the geometry in the other direction. You may also find that you need to resize the length of your line if its new location requires a different length. Double-check that the length of each line is not sticking past the outer contour or crossing any unwanted geometry. 

Repeat this process for the remaining bend lines. 

4. Apply Bend Deduction

Once the bend lines are in place, we need to consider the Bend Deduction. 

The overall length of sheet metal becomes stretched out when the sheet metal parts are bent. Bend Deduction is used to counteract material stretch caused by forming. Bend Deduction is unique to each material type, thickness, and bend angle, so we recommend using our Bending Calculator, which makes it easy to factor in bend deduction!

In the Bending Calculator, start by selecting the desired material. For example, we’ll be making this box out of 304 Stainless Steel, using a thickness of .03. The top flange length is 2.26 inches, with a desired angle of 90 degrees. The calculator then generates the total Modified length, which is 12.2085 inches. 

Back in Adobe Illustrator, we can copy and paste this to the height of our overall contour. You will then want to repeat the process per each direction the part includes bending. 

Once complete, your design is all set and ready for uploading! Be sure to check out our other video on Exporting from Adobe Illustrator for Laser Cutting and then reference our checklist to double-check that your file meets our latest requirements.

Pre-flight Checklist

Before you upload your design files, be sure to go through our pre-flight checklist:

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