How to Make a Metal Prototype?

What is a metal prototype?

Prototyping is a model or sketch of a product in manufacturing. Prototypes are made before production starts, so designers can verify and update parts. Metal prototyping has been widely used in many industries. Automobile, medical, aviation, construction, aerospace, technical design, and other industries often use metal parts in consideration of the advantages of metal parts when designing.

When you should use metal for prototyping?

Plastic may be used in early prototype stages in the parts that in the end be a metal. This is because no mechanical or functional requirements are needed in the early prototype stage. And plastic can achieve the same effect at a lower cost than metal. In terms of functional testing, if the product is designed to be a metal, then a metal prototype will be applied.

 Advantages of metal prototype:

  • Superior strength-metals, especially stainless steel, it’s strong, hard, and very durable.

Even when making detailed prototypes, metal can withstand almost anything and maintain the design perfectly.

  • Higher heat resistance-Compared with plastic, the melting point of the metal is much higher, which makes it less risk of degradation in high-temperature environments.
  • Cost-effectiveness-Unlike popular belief, metal is more cost-effective than plastic in many cases. The performance of the metal reduces the frequency of replacement and dilutes the cost over time.
  • Better aesthetics-metal products are often more advanced than plastic products and can arouse people’s love.

How to get a prototype in metal?

Metal prototypes that can be made from different materials vary from different manufacturing processes. There’re many metal manufacturing techniques like CNC machining, casting, extrusion, 3D printing, or sheet metal.

Metal machining prototyping

CNC machining uses numerical control machine tools and milling machines with three to five CNC axes. These machines are automatic and controlled by a computer to remove material from a block-based on 3D files.

There are many metal materials to choose from CNC processes such as aluminum, steel, titanium, zinc, magnesium, and so on. Requiring no molds or MOQ, CNC machining is a fairly cheap option for the prototype stage.3-axis, 4-axis and 5-axis CNC machine tools provide extraordinary flexibility for manufacturing complicated and parts with features.

However, due to the subtractive nature of this process, there is some material waste.

In the below picture, this is a reflector machined in aluminum by CNC milling. 5-axis is required because of its complex structure. The whole part is milled from an aluminum block, it’s kind of a waste since it needs to remove much material. But in a term, it’s a save of cost and time using CNC milling to prototype complicated and strong enough products for updating the iteration.

Sheet metal prototyping

In the sheet metal manufacturing process, the sheet metal plate is placed on a flatbed, where the laser cutting machine executes according to programs. Sheet metal will be processed punching or stamping different features according to different requirements. After the parts are deburred, they move to the bending machine, where they form the final geometric shape. Post-processing is usually used to complete sheet metal parts.

Sheet metal processing is widely used in mass production due to its fast delivery time and high-quality surface finish, while tooling is needed before production starts.

Metal 3D printing prototypes

Metal 3d printing, also known as direct metal laser sintering (DMLS) and direct metal laser melting (DMLM), is an additive layer technology.

A metal 3D printer uses a laser beam to fuse layers of metal powder. The powdered metal is scattered throughout the build platform and is selectively melted onto the previous layer according to 3D files.

The biggest advantage of metal printing is flexibility in geometry.

Metal printing prototypes are available for very complex features, including the complicated internal undercut, since they are made layer by layer, rather than cut from solid blocks.

But powder materials are used in 3D printing, which means there are fewer materials to choose from.

In addition, the printed parts are not very strong compared to the processed parts.

Aluminum Extrusion prototyping

Aluminum extrusion is also a metal processing technology and is not generally considered a prototype method. When it comes to extrusion, materials are forced to go through a shaped open mold, producing a long part with the same cross-section. They will finally be cut to the required length.

Most companies dealing with extrusion just handle high production, and one-time samples do not attract their interest. If only one or a few sets of extruded structural parts are needed in the prototype stage, we usually purchase aluminum tubes from the market and implement them through additional CNC processing.

Extrusion is only performed on aluminum and is only suitable for parts with a simple structure such as metal tubes, joints, and brackets.

Casting method for prototypes

Metal casting is a process of funding hot liquid metal into a tool or mold that contains a hollow recess or cavity to achieve the desired shape of the finished product. The liquid metal is then removed from the mold and allowed to solidify.

Due to the need for tools or special equipment before production, metal casting is usually not considered a prototype process. This is a process suitable for mass production.

Casting metal models are more expensive, however, the molds can be reserved for mass production, which may ultimately save cost in the long-running.

Summary

As an ISO9001 certificated prototype company with more than 20 years’ experience, we’re good at metal prototyping services. I’m sure we can do something for you. If you are looking for a prototype company to complete your design, please don’t hesitate to be in touch with us.

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