Makers and designers all over the world are turning to CNC milling to turn their designs into prototypes. What exactly is this new high-precision technology? As computers and technology improved over the last decades, machines have been enabled to do a lot of the work that manual labourers usually had to do. Making the production of parts much faster.
There are many industries that need precise, consistent, complex, and accurate cuts to create specialized parts for equipment. These industries include dental, electronics, transportation, publishing, aerospace, agriculture, firearms, metalwork, manufacturing and military. By creating intricate parts, many of these industries have been able to excel and grow at a rapid rate.
If you are a maker or a designer considering using a CNC milling shop, then read along to discover exactly what it is.
WHAT ARE CNC MACHINES?
Also known as Computer Numerically Controlled are electro-mechanical devices that can control tools around a variety of axis. These tools can cut through metal, plastic, and steel to create precise parts, including Highly Customized Graphite Parts, by following instructions from a computerized file.
This process is one of two that can be used by machinists, makers, and designers to physically create parts that they design on a computer. The other process is 3D printing.
The first CNC machine was created and developed in the early 1940s. At first, to create CNC milling parts, the process used a punched tape format to receive data which is read from. This was much more time-consuming as the punched tape had to be manually made and fed to the machine. One mistake on the sheet and a machinist had to start all over again.
Since then, the entire process has undergone rapid growth leading to a more modern approach. Today, designers use digital instructions also known as G-code to give instructions to machines. CAD and CAM programs on computers make this process much easier. Allowing the designer to create a 3D computerized model before sending the G-code to the milling shop.
WHAT’S THE DIFFERENCE BETWEEN CNC AND 3D PRINTING?
3D printing is also known as additive manufacturing. The main difference between the two processes is that 3D printing adds while Computer Numerically Controlled machining subtracts. With CNC machining material is removed from either a flat sheet or block of stock, while with 3D printing the part is built up from scratch by ejecting a liquid from a printing-type nozzle.
3D printing also uses processes known as FDM (fused-deposition modelling), SLS (selective laser sintering), SLA (Stereolithography) and SLM (selective laser melting). Depending on your project’s needs you’ll be able to assess whether CNC milling is for you or 3D printing.
Both processes come with a set of pros and cons. 3D printing is much more affordable than the other but can’t print high-quality materials like titanium or steel. CNC machining is more expensive but it runs at a much faster time, uses high precision, and can create heavy durable parts.
BENEFITS OF USING A COMPUTER NUMERICALLY CALCULATED PROCESS?
There are many benefits to using a milling shop for your project. Here is a list of the top benefits:
- One skilled person is in charge of operating several machines
- It’s extremely precise as it can achieve an accuracy of up to one-thousandth of an inch
- It doesn’t require as much manual labour as conventional machining processes. A skilled technician will oversee the project by inputting the G-code and overseeing the machine do the work
- The machine can create hundreds of the same parts, creating consistent high-quality uniform parts
- Fixing errors is much easier. After prototyping, one can fix minor problems by adjusting the G-code
- CNC machines have high endurance and can produce 24/7, the only time they stop is when they have to undergo maintenance. Compared to manual labour where time off is needed
- There is great versatility attached to CNC machining itself. Designers can create virtually any part with the most intricate curves or smoothest surfaces
- It’s a low-maintenance process that only requires regular tool check-ups and software updates
- Programs can easily retrieve previous projects as it is saved in a master file
- It can produce thousands of the same parts within hours. Check out this extremely fast milling machine in action: https://www.youtube.com/watch?v=osqX7iQEnuI
There are a few disadvantages to be aware of too. CNC milling is quite costly. Since the process requires highly intelligent machining and supervision it can cost more than conventional machining. The speed and precision that it works at make up for the money spent.
One other disadvantage is that it creates a lot of waste material. By cutting away at a block or stock of material, the excess cut-offs can’t be re-used. Some materials are recycled whilst most have to be thrown away.
WHAT MATERIALS CAN BE USED?
Compared to 3D printing which can only use softer plastics, CNC machining can cut through strong and durable materials. Materials like:
- Polypropylene
- Wood
- Titanium
- Fibreglass
- Foam
- Steel
- Stainless steel
- Copper
- Aluminium
- Brass
The machine cuts away at a stock of any of the above materials. Then it buffs and smooths out the part to precision. Essentially, one CNC machine replaces a variety of cutting chores done by conventional machining. Chores include welding, grinding, grooving, shaping, stamping, punching, shearing, welding, turning, milling, contouring, knurling, and lathing.
Compared to conventional machining, this process is much faster and more accurate. As it can create physical parts up to a 0.0001-inch precision.
Using a CNC milling machine shop will be greatly beneficial to your project. Not only will it create a series of precise parts, but it will also speed up the production of your design. Manual lathing needs a skilled technician for every type of machine, whereas with CNC machining one experienced technician can operate several machines. As a result, you’ll have one person overseeing your entire project, focusing on the end result.
