What is additive manufacturing?
Additive manufacturing (AM), also referred to as “3D printing,” is a process when you start with nothing, adding material that results in a completed part; whereas, with subtractive manufacturing, the material is cut away to form a completed part.
Additive manufacturing uses a CAD model, or 3D model, in combination with a splicing software used to generate M-code and G-code that tell the print head where to put material, layer on layer on layer, to complete very precise geometric patterns and shapes.
Additive Manufacturing helps diversify the materials used in all industries. It can be used in all commercial and industrial manufacturing processes.
At Rutherford Manufacturing Group, we utilize 3D printing to make parts lighter, stronger and achieve complicated geometry that traditional manufacturing cannot.
3D Printing has many different kinds of technologies and processes that are used to create the object. Some popular systems include Powder Bed Fusion (PBF), Direct Metal Laser Sintering (DMLS), Material Jetting, and Sintering.
At RMG, we utilize a Bound Metal Deposition Technology (BMD). This eliminates the safety requirements associated with metal 3D printing while enabling new features like the use of closed-cell infill for lightweight strength. The system includes a printer, debinder, and furnace.
Why choose additive over subtractive manufacturing?
Additive manufacturing can achieve a higher level of geometric complexity.
Subtractive has more limitations in this aspect.
3D printing is a cheaper and faster way of prototyping parts than subtractive manufacturing. This helps creators visualize and field test parts faster.
3D printing produces almost no waste. The subtractive process has considerable more material waste.
3D printing can be used in various environments to create everything from small parts to large, on-site structures like buildings. This will be particularly useful in aerospace applications when building on site will be required.
What is subtractive manufacturing?
Subtractive manufacturing is a process by which material is cut away from a solid block of material. This form of manufacturing can be done manually or by CNC methods.
Common subtractive machine examples include Mills, Lathes, Drill Press, Grinders, Saws, Laser Cutter, and Water Jet Cutting. Most of these machines can be operated manually, however, with the power of the computer, these can be operated robotically with CNC (Computer Numerical Control).
Why choose subtractive over additive manufacturing?
One major advantage of subtractive manufacturing is the ability to machine extremely thin material. This is a significant challenge for 3D printing.
Additionally, subtractive manufacturing can be a better, faster solution for mass production. CNC mills and lathes are made so that the machine can run 24 hours per day automatically. Tool paths for subtractive machining can run at much faster feeds rates resulting in less cycle time. 3D printing can only run so fast because the system relies on heating and cooling processes that come at the expense of time.
CNC machining can accommodate very complicated geometry utilizing 3, 4, 5 axis tool paths. Almost any material can be machined to create the perfect part.
At this time, subtractive manufacturing is still widely considered the standard method of manufacturing. It has a longer track record of production and can be relied on when manual processing is needed. Milling can be must faster than 3D printing in most scenarios, but it really depends on the geometry and requirements of the part.
Is additive or subtractive manufacturing better?
The short answer is, it depends. The first thing you need to consider is the goal you have in mind.
Are you wanting a prototype for a visual example or to test a product? If so, 3D Printing or additive manufacturing is likely the way to go. Do you require thousands or even millions of parts in a short amount of time? If so, machining parts on a mill or lathe via subtractive manufacturing is most likely the best solution.
Are you trying to consolidate how many parts a project requires? 3D printing allows engineers to combine components together as one piece to improve part function and overall lower cost. Machining will never be able to accomplish this in the aspect of combining components to minimize the parts required. 3D printing is much faster and cheaper at this process than machining.
At Rutherford Manufacturing Group, we believe 3D printing, in certain environments, can allow for higher quality components that require less overall production time, lower production cost. Fewer parts make for better part management. For example, if you wanted to build a structure or building on the Moon or Mars, it will require robotic 3D printing. It is much safer to send a machine in to do hazardous work in an unforgiving environment.