Sheet metal prototyping and fabrication is the backbone of the modern industry, especially in the automotive and aerospace industries. Sheet metal can be used to manufacture parts like appliance, brackets, enclosures, panels, and chassis. A high-quality and strong sheet metal prototype or part makes a great difference. And sheet metal design plays a significant role in achieving that.

In addition to partnering with a professional and experienced CNC prototyping factory, an accurate and reasonable design is also vital for you to get sheet metal prototypes or parts that meet the expectation. In fact, research showed that manufacturers spend at least 30% of their time fixing the design errors and most of these errors involve manufacturability. Designers or engineers should have a clear design purpose and plan to ensure that their sheet metal design is cost-effective and easy to manufacture. When designing, factors including function, mechanical properties, thickness, features, tooling methods and tolerance should be mulled over according to the actual application.

This article is to offer some tips and guidelines that help designers and engineers turn out sheet metal designs that are highly functional as well as easy to manufacture.

Take Care Holes Design of Your Sheet Metal Prototype

As the sheet metal is often used to make the sheet metal prototype that requires holes and slots for screw, bolts or interlocking sections, such as brackets and enclosures, in the design, specifying the sizes, positions, and alignment of holes is vital. Here are some rules of thumb to follow: 1) The hole diameters should be larger than the thickness of the sheet because if the diameters are less than the thickness, it would cause higher punch loading, longer time to burnish, and excessive burr. It could also lead to slug-pulling that affects the life of the metal sheet as well as punch. 2) It is also important to leave appropriate space between holes, generally at least twice more than the sheet’s thickness. Space between holes helps ensure the strength of the sheet metal and protect holes against deformation in forming or bending process. 3) When the holes must be designed to near to the edge, the space between holes and the edge should be at least as big as the thickness of the sheet. 

Partnering with an experienced CNC prototyping factory and asking for advice is essential. The mistakes in design can lead to finished sheet metal prototypes or parts that look and function differently from expected.

Manage Tolerances in Your Sheet Metal Prototype Design

There are many variables that affect tolerance of sheet metal parts, such as the function, feature, material, the thickness, as well as the capability of the CNC prototyping factory you work with. Besides, the fabrication process that converts the sheet metal into a prototype and part, the die accuracy, and the wear during the punching process should also be considered carefully to ensure accurate tolerance. Designers should also consider the space between parts when determining tolerance. The zero clearance between parts can create a tolerance stack-up, thereby leading to the finished sheet metal parts that do not match to other components when assembling.

Consider Tooling Options for Your Sheet Metal Prototype

The tooling can limit the shape of your sheet metal prototype. For example, conventional press-brake tooling always results in straight-line bends that are frequently used on most sheet metal parts. By constraining your design to this shape, you can get the lowest cost and fastest lead times. And a punch press is widely used to create more detailed features like round embosses countersinks, bridge lances, and others. In this case, using standard sizes whenever possible is suggested. 

It is the most economical to use configurations of common tools instead of part-specific tooling.

Deal With Bends of Sheet Metal Prototype

Bending is one of the most important processes in fabricating a sheet metal prototype. With equipment like machine presses and brakes, a CNC prototyping factory can manufacture the originally flat sheet metal to various shapes. Here are a few of our rules of thumb to follow when you design sheet metal part with bends: 1) The radius of inside bend should not be less than the thickness of sheet metal. It can help avoid deforming. 2) Keeping the bending direction consistent with the bending radius can help reduce fabrication costs, making parts more cost-effective. 3) Designing the bends that can be manufactured by standard tools and forming process is more cost-effective and efficient. Special bending methods or tools always slow down manufacturing speed and add significant cost.

Final Thoughts on Designing Sheet Metal Prototype

The sheet metal design starts with function which in turn dictates design. So many factors can affect the final result. Is it strong enough? Light enough? Does it match other components when assembling? Does it look and work the way you expect? Is it too expensive to manufacture? 

For the sheet metal prototype with a complex design, the above rules of thumb may not apply. It is common for manufacturers in many industries including automotive, aerospace, industrial equipment, electronics, household appliance, and so on, to outsource the sheet metal designing, prototyping, and manufacturing to a specialized and experienced prototyping factory who offers comprehensive sheet metal prototyping services. In this way, they can focus on their core activities and get high-quality results at the same time. (>>>> Rapid Metal Prototyping Application: Why Manufacture Sheet Metal Prototype)

Do you want to design and fabricate a sheet metal prototype that meets your expectations in terms of function, features, mechanical properties, as well as manufacturing costs and time? Tuowei is a professional CNC prototyping factory that has extensive expertise in sheet metal manufacturing processes, rich past experience of successful projects, and needed technical resources to complete your project with great satisfaction. For more detail information and professional advice, please contact our customer service.