Fusion 360 Sheet Metal Design 2 — Questions and Answers
Question 1: In Fusion 360's Sheet Metal workspace, what does 'Unfold' allow you to do?
- Delete a bend feature
- Temporarily flatten selected bends so you can add cuts or features on the flat surface (Correct answer)
- Convert a solid body to sheet metal
- Export the part to a 3D printer
Correct answer: Temporarily flatten selected bends so you can add cuts or features on the flat surface
Unfold lets you select specific bends to flatten temporarily, enabling features like slots or holes that span across a bend line.
The Unfold command in Fusion 360 allows you to flatten one or more bends while keeping the rest of the part folded. This is useful when you need to cut a hole or add a pattern that crosses a bend. After adding the features, you use Refold to restore the bends. The flat pattern captures all features correctly after refolding.
Question 2: What is 'hem' in the context of Fusion 360 sheet metal design?
- A decorative weld bead
- A folded edge that doubles back on the sheet to create a safe, reinforced edge (Correct answer)
- A bend angle greater than 180 degrees
- A type of material finish
Correct answer: A folded edge that doubles back on the sheet to create a safe, reinforced edge
A hem folds the edge of a sheet metal part back on itself to eliminate sharp edges and add rigidity.
Hems are used in sheet metal design to eliminate sharp cut edges and strengthen the perimeter of a part. In Fusion 360, you can create hems using the Hem command, choosing from types such as flat, open, tear-drop, or rolled. Hems are common in consumer electronics enclosures and automotive panels.
Question 3: Which parameter primarily controls the inner radius of a bend in a Fusion 360 sheet metal part?
- Bend angle
- Bend radius (Correct answer)
- K-factor
- Material thickness
Correct answer: Bend radius
The bend radius is the radius of the inside curve of a bend, controlled as a sheet metal rule or per-feature parameter.
The bend radius specifies how sharp or gradual a bend is. A smaller radius creates a tighter bend, while a larger radius is more gradual. Bend radius is typically set in the Sheet Metal Rules dialog and applied globally or per feature. It affects both the appearance of the part and the flat pattern stretch calculations.
Question 4: What does the 'Convert to Sheet Metal' command do in Fusion 360?
- It exports a design to a sheet metal supplier
- It transforms an existing solid body into a sheet metal part by identifying a face as the base flange (Correct answer)
- It applies a metallic appearance to a body
- It imports sheet metal templates from the cloud
Correct answer: It transforms an existing solid body into a sheet metal part by identifying a face as the base flange
Convert to Sheet Metal allows you to take a solid modeled body and apply sheet metal rules, selecting a face to define thickness and material.
When a part is modeled in the Design workspace without sheet metal tools, you can use Convert to Sheet Metal to redefine it as a sheet metal part. You select a face as the base wall, specify thickness and bend radius, and Fusion 360 identifies bend edges. This enables flat pattern generation and sheet metal rule application.
Question 5: In a Fusion 360 sheet metal drawing, what line type typically represents bend lines on a flat pattern?
- Solid centerline
- Dashed hidden line
- Dotted phantom line
- Dash-dot chain line (Correct answer)
Correct answer: Dash-dot chain line
Bend lines in flat patterns are shown as dash-dot (chain) lines to distinguish them from cut edges on manufacturing drawings.
In engineering drawing standards, bend lines on sheet metal flat patterns are represented by dash-dot chain lines. This distinguishes them clearly from the solid outlines that represent actual cut edges. Most CAD systems, including Fusion 360, follow this convention when generating drawing views from flat patterns.
Question 6: What is the effect of increasing the bend radius relative to material thickness in a sheet metal part?
- The bend becomes sharper and more prone to cracking
- The flat pattern becomes smaller
- The bend is more gradual, reducing the risk of cracking in brittle materials (Correct answer)
- The K-factor decreases proportionally
Correct answer: The bend is more gradual, reducing the risk of cracking in brittle materials
A larger bend radius spreads deformation over a wider area, reducing stress concentration and the risk of cracking, especially in harder or thicker metals.
When the bend radius is increased, the material deforms over a larger area, reducing peak strain at the outer surface of the bend. This is critical for materials with lower ductility, such as high-strength steel or thick aluminum. As a rule of thumb, the minimum bend radius is often expressed as a multiple of the material thickness (e.g., 1T, 2T).
Fusion 360 Sheet Metal Design 2
In Fusion 360's Sheet Metal workspace, what does 'Unfold' allow you to do?