Roll forming is a common method of sheet metal processing, but if it is not designed properly, it can cause processing problems, increase production costs and time. This article will detail 7 common roll forming design flaws and how to avoid these problems through proper design to improve product quality and production efficiency.
1. Small bend radius
Problem: A bend radius that is too small can cause cracking on thick sheet, galvanized or pre-coated materials, especially on the outer fiber part where stress is generated during bending. It also increases tool wear and requires more power to operate the equipment, which increases costs.
Solution: It is recommended that the bend radius be at least 1.5 to 2 times the material thickness. Alternatively, a more ductile material can be selected to process the component to reduce the risk of cracking.
2. Extremely short flanges
Problem: If the flange (i.e. the leg of the part) in the design is too short, it will make the forming process difficult and cannot be formed correctly. In addition, short flanges make processing more difficult, especially when bending on thick materials.
Solution: Design the flange to be at least 3 times the material thickness. Longer flanges provide more leverage and help bend heavier materials.
3. Wide curved surfaces
Problem: Large bends (such as half-tubes) may not exceed the material’s yield point, making it difficult to control the shape. Such shapes are more likely to spring back, resulting in reduced precision of the formed part.
Solution: Large curved surfaces can be broken down into multiple discrete curved straight areas during design, which can reduce tool design costs and reduce initial scrap. Alternatively, choose a material with a lower yield strength so that the curved curve can better maintain its shape after bending.
4. Blind corners (air bends)
Problem: Blind corners, also known as air bends, occur when the roll die cannot contact both the inner and outer corners of the formed part at the same time. This bend is often imprecise and difficult to maintain consistently throughout the forming process.
Solution: Avoid blind corner designs and ensure that the inner and outer corners of the part are always in contact with the die during processing. This maintains forming accuracy and improves production consistency.
5. Narrow openings
Problem: Cutting the mold can become very complex if the opening is too narrow compared to the overall shape of the part. Narrow openings can also result in rolling dies that require frequent maintenance or even breakage of the cutting dies.
Solution: When designing, ensure that the opening width is at least half of the section width. Such a design can effectively reduce mold damage and maintenance frequency.
6. Deep vertical sections
Problem: Deep, vertical sections require the use of large-diameter forming dies, which significantly increases tooling costs. Additionally, these components may need to be partially formed by rolling and then secondary processed through a press brake.
Solution: Try to make the straight part wider or widen the angle of the side wall. If you must design deep and narrow channels, consider using special technologies such as MeshTrim.
7. Shapes with wide unformed edges
Problem: The unbalanced nature of sheet metal components that have high antisymmetry or long, unformed flat edges can cause parts to easily twist or wrinkle during machining.
Solution: Add a small leg to the unformed edge, or introduce reinforcement ribs to increase overall strength and ensure consistent molding during processing.
How to optimize sheet metal component design?
In addition to avoiding the design flaws mentioned above, good design should also take into account the tolerance range. Setting tolerances too tight can increase manufacturing difficulty and cost, while too loose tolerances can affect the quality of the finished product. Therefore, ensure that the tolerances are tight enough to meet quality and functional requirements, but also give the manufacturer enough room to produce.
Other ways to optimize sheet metal component design include:
Smart roll forming die design: Proper die design can minimize scrap, reduce tool wear, and improve production efficiency.
Partner with a roll forming manufacturer: Partner with an experienced manufacturer early on who can help identify potential problems in the design, make suggestions for improvements, and optimize manufacturability.
Proper metal material selection: Choosing the right material based on the needs of a specific project can not only improve the quality of the finished product, but also effectively reduce costs.
Use the right equipment: Make sure to use the appropriate roll forming equipment and customize the production line according to the design requirements to improve production efficiency.
Why work with a roll-forming partner early in the design phase?
Working with a roll-forming partner early in the design of a sheet metal component offers several benefits:
Identify potential problems: An experienced manufacturer can identify problems early in the design process, saving time and money by avoiding repeated design changes later.
Optimize the design: The manufacturer can suggest modifications based on the forming process to improve the manufacturability of the component and potentially reduce production costs.
Material selection suggestions: The partner can recommend the appropriate metal material based on the design requirements to ensure that the material meets the requirements of the roll-forming process.
Cost considerations: Early collaboration allows both parties to discuss the cost impact of design choices to develop the most cost-effective production plan.
How to choose the right sheet metal manufacturer?
On top of avoiding design flaws, choosing an experienced sheet metal manufacturer is the key to achieving success in roll-forming. A qualified partner can not only provide valuable input during the design phase, but can also help optimize the design, provide material selection suggestions, and suggest possible cost-saving methods.
By avoiding the above design flaws and working with the right manufacturer, your roll-forming project will be more likely to be successful and produce high-quality sheet metal components.
Contact Us: If you are looking for a manufacturer of sheet metal components or would like to learn more about the roll forming process, please contact the ZTRFM Forming machine team today to learn more about the possibilities of roll forming.