3D printing has been around for a long time and started as a prototyping tool which eventually evolved into larger applications such as building homes and vehicles. Every day, innovators are finding new ways of using 3D printing technology to make the world a better place.
The best alternatives for 3D printing are CNC machining, sheet metal fabrication, wood fabrication, and plastic injection molding. 3D printing is a popular method for prototype creation due to its low cost and reliable results combined with a large variety of materials to work with.
In the world of prototyping, many people want to create complex products with other materials such as wood, metal, and plastic. 3D printing cannot produce complex parts from metal or wood through bending, welding, or other processes.
Here are some 3D printing alternatives that can accomplish what would otherwise be impossible using 3D printing.
CNC Machining
Computer Numerical Control (CNC) machining is a process where a pre-programmed computer dictates the movement of the machine. Such tools include CNC routers, mills, lathes, and even grinders. This process takes place in favor of the limitations of manual controls. CNC machines automatically will follow the path and tooling as defined by the programmer and in some cases involves little to no feedback from the operator.
When you activate a CNC system, it controls the machines and replicates the 2D and 3D drawings into objects as defined by the programmer. Basically, a numerical control machine dictates the machine’s movent and tool feeds and speeds which carry out the dimensional tasks.
In CNC machining, machine movement is directed across X and Y axes and the tools are guided and positioned via servo motors. For industrial applications (such as metalwork) accuracy, speed, and consistency are crutial.
There are many different types of CNC machines used today:
CNC Mills – CNC mills run on programs consisting of letter and number-based prompts that guide the machine to the correct coordinates. Typically, a CNC mill has a three-axis system – X, Y, and Z. However, some machines accommodate additional axes.
Electronic Discharge Machining (EDM) – EDM is also referred to as spark machining. This process involves the molding of workpieces into shapes using electrical sparks. With this process, current discharges occur between two electrodes.
Lathes – with lathe machines, the product is cut by engaging a tool into a rapidly spinning material. The process relies on indexable tools to cut with high velocity and precision.
Sheet Metal Fabrication.
Sheet metal fabrication is a method that involves multiple processes to create a product from cut and assembled sheet metal components. All sheet metal fabrication processes are procedural, so you must incorporate the right processes to achieve the desired result.
These processes include cutting, forming, and assembly.
Cutting
Cutting is a complex process that includes mechanical cutting, laser cutting, water cutting, and plasma cutting.
In cutting, manufacturers use different methods namely plasma cutting and waterjet cutting. In plasma cutting, powerful torches shoot an electrical arc through compressed air. By doing so, the air ionizes, generating a powerful flame that slices through any metal, such as stainless steel or aluminum.
With waterjet cutting, they use waterjet cutting machines that super pressurize a stream of water. They do so by passing the water through a minuscule nozzle. Since the water is now a concentrated beam, it can slice through metal plates.
Bending
The process of bending involves placing sheet metal under intense pressure to deform the material into different shapes. Manufacturers commonly use methods such as coining, roll forming, and air bending in this process.
Assembly
The process of assembly involves the joining of different metal components to build the desired products. In assembly or joining, welding, and riveting are all common assembly methods in manufacturing.
Wood Fabrication
Wood fabrication is similar to metal fabrication, manufacturers can make large-scale products out of wood which is impossible with a desktop 3D printer. Creating large-scale products or components is not the only ability of a CNC router or mill.
With CNC mills, the entire workflow from CAD to cutting is very easy and straightforward. In fact, you can typically do so with zero CNC experience or knowledge. Thanks to CNC mills, manufacturers retain the wood’s strength and natural beauty.
Another machine commonly used in wood fabrication is a lathe. The machine works by rotating the workpiece around a stationary cutting tool, but you can also perform various other operations besides cutting. These operations include sanding, drilling, knurling, facing, deformation, and turning. Basically, the main use of a lathe in wood fabrication is to remove unwanted parts and leave behind a nicely shaped object.
Plastic Injection Molding
Plastic injection molding is one of the best 3D Printing alternatives for the mass production of objects from thermoplastics. However, unlike sheet metal and wood fabrication, there is no welding, stamping, or bending.
In this process, a thermoplastic polymer is usually heated above its melting point until it becomes a viscous liquid. Then, it’s forced into a closed mold which defines the shape of the end product. Once the viscous liquid is injected into the mold, it’s allowed to cool where it reverts into solid plastic.
To retrieve the product the mold is usually able to be opened. While the process sounds simple, it’s not. There is complex behavior of plastic as it melts and additional difficulties in the ability to produce complicated products.
The mechanisms of plastic injection are pressure, flow, and heat transfer. To complete the process, you need an injection molding machine. This is an essential piece of equipment known as a press. With plastic injection molding, manufacturers can produce complex parts for various applications.
Conclusion
3D printing keeps production costs extremely low and this makes creating prototypes and products available to small businesses and hobbyists without access to expensive machinery. It also reduces the time between the conception of an idea and the sale of products.
3D printing also reduces lead time especially when it comes to short production runs. This allows the creation of complex parts and objects without added costs. For example, plastic injection molding needs mass production to even out the overhead costs. But the 3D cost of manufacturing a single small item remains the same.
Since the cost remains the same for every added unit, it’s possible to make unlimited changes to the products. This is why 3D printing has always been favored for prototyping, unlike traditional fabrication. However, 3D printing can be progressively more expensive in time and cost, which is true especially when it comes to mass production, smooth finish, and the production of very complex objects.
