How to Create Flanges in BricsCAD Mechanical

Quick answer: A flange is the main feature of most sheet metal parts, creatable several ways: a base flange from a closed 2D profile defining its boundary, one or several edge flanges by pulling edges of existing flanges, or several flanges at once by extruding a 2D polyline (every linear edge of the polyline becomes its own flange). Flanges can also form as elements of lofted parts, or get recognized within existing geometry (see this hub’s separate articles on creating and splitting lofted bends, and converting to sheet metal and repairing). In contrast to history-based MCAD, BricsCAD applies the same set of tools to modify any flange independently, confirming the history-free philosophy covered on this hub’s part design methods page.

Creating a Base Flange

Select a closed planar profile and run SMFLANGEBASE, via the Create Base Flange tool button on the Sheet Metal toolbar, the Sheet Metal menu, or the Sheet Metal group of the Quad cursor menu. It extrudes the profile; the base flange’s height defaults to the part’s Thickness property, change it by typing a new value in the Thickness field of the Mechanical Browser.

Creating Edge Flanges

1. Select a linear edge.
2. Choose SMFLANGEEDGE from the Sheet Metal section of the Quad cursor menu.
3. Move the mouse to define the edge flange’s length and the angle between the two flanges, or use the dynamic dimension fields to enter exact values.

To make an edge flange narrower or wider than the edge itself, choose the Width option of SMFLANGEEDGE and define the offset distance from one or both sides of the edge (bend reliefs generate automatically in this case).

Taper angles: create trapezoidal edge flanges using the Taper angle option of SMFLANGEEDGE.

Creating Multiple Flanges by Extruding a Polyline

A simple but important class of sheet metal parts looks like a thickened polyline when viewed from the front. Build one either with sequential calls of SMFLANGEEDGE, or by drawing a polyline and running DMEXTRUDE, then DMTHICKEN, SMCONVERT, and SMBENDCREATE. The recommended approach, though, uses SMEXTRUDE directly, letting you draw the part within a complex assembly without interfering with other entities, and control the thickening direction of every line segment individually.

1. Draw a polyline sketching the future sheet metal part, then run SMEXTRUDE, via the Extrude Polyline tool button on the Sheet Metal toolbar, the Sheet Metal menu, or the Quad cursor menu’s Sheet Metal group.
2. Hover the cursor to select an extrusion height, or type a value and press Enter to accept it.

The body creates with its extensions respected, never exceeding the original polyline’s dimensions, this holds true across different thicknesses (1 mm, 2 mm, or 4 mm, for example, all preserve the same external footprint). This dimension-preserving policy also applies to sheet metal parts built through other workflows: sequential flange building with SMFLANGEEDGE, bends created with SMFLANGEBEND, and sheet metal recognition with SMCONVERT. To change a flange’s extrusion direction, apply SMFLIP to it.

Extruding a Contour to Create a Flange

SMFLANGECONTOUR extrudes a given contour into a new flange and attaches it to the model, conceptually equivalent to a sequence of SMFLANGEBASE, SMFLANGECONNECT, and SMBENDCREATE. In practice, it intelligently identifies the thickness faces on the selected flanges and connects them to the new flange’s own thickness faces.

Launch it via the Create Flange from closed Contour tool button on the Sheet Metal toolbar, the Sheet Metal menu, or the Quad cursor menu. Select the required flanges, then click the contour, the command creates a new flange and merges it with the selected flanges on the part.

Bends, Corner Reliefs, and Junctions

Pulling an edge flange with SMFLANGEEDGE automatically creates a bend feature between it and the base flange, a corner relief feature at any corner where three flanges meet, and a junction between any two flanges that aren’t connected by a bend.

Creating Multiple Flanges Simultaneously

1. Launch SMFLANGEEDGE and select multiple edges.
2. Create the edges dynamically: define the angle and flange height using the dynamic entry fields, pressing Tab to switch between the Angle and Distance fields.
3. Select the inside edges of the newly created flanges.
4. Create the flanges; the command automatically calculates their intersections and creates junction or miter features accordingly, miters at 90 degrees, junctions at other angles, always avoiding material conflicts.
5. If the flanges were created externally, use the Toggle option (or widget control) to adjust the connection type for both miters and junctions.

Frequently Asked Questions

How do I change which direction a flange extrudes after it’s already created? Apply SMFLIP to it.

What determines whether BricsCAD creates a miter or a junction when multiple flanges intersect? The angle between them, 90 degrees produces a miter, any other angle produces a junction.

Can I create a trapezoidal (tapered) edge flange rather than a rectangular one? Yes, using the Taper angle option of SMFLANGEEDGE.

What’s the difference between building a thickened-polyline part with sequential SMFLANGEEDGE calls versus SMEXTRUDE directly? SMEXTRUDE lets you draw the part within a complex assembly without interfering with other entities, and control the thickening direction of each line segment individually, both harder to manage with sequential edge flange calls.