While both are computerized fabrication processes, CNC machining and 3D printing differ significantly in terms of processes, materials, production capabilities, and final product outcome. Though the two processes may occasionally produce similar results in specific applications, they achieve those results quite differently.
CNC machining is a subtractive manufacturing method that uses pre-programmed cutting tools to shape parts and components from a piece of stock material. Conversely, 3D printing uses additive measures to create pre-programmed shapes from melted plastic, resin, and metal. Both methods are automated and highly dependent on computer software, but they are fundamentally different processes.
Additive Manufacturing vs. Subtractive Machining
To understand the basic difference between CNC machining and 3D printing, it is important to understand the difference between additive and subtractive manufacturing processes.
- Additive manufacturing, as its name implies, is based on the addition of material to create a part or component. In most cases, such as 3D printing, parts are created from a melted material which is layered and shaped in accordance with pre-programmed specifications.
- Subtractive machining begins with a larger stock of raw material, which is then cut or milled away in fine amounts, thereby producing the final desired shape. Unlike additive processes, subtractive machining does not require melting and curing of raw materials and as a result can be used on a greater variety of materials.
Materials Utilized for CNC Machining & 3D Printing
Due to their different fundamental fabrication methods, CNC machining and 3D printing have different material capabilities. Specifically, additive 3D printing has more functional limitations than subtractive CNC machining.
CNC Machining Materials
CNC machining can be used to create parts and components from a wide range of materials, including:
- Fiber in-layered composites
- Machining wax
- Modeling foam
- Metals and metal alloys
3D Printing Materials
3D printing is much more limited in its range since the material must be able to melt into a liquid state in order to be printed to the required specifications. The vast majority of 3D printing uses plastic resins, though the latest developments in the technology have expanded material options for certain printer types.
Materials available for 3D printing include:
- Wood filaments
- Metal filaments (carbon, titanium, steel)
Although 3D printing can produce some metal- or wood-based products, the end products have a reduced durability and temperature resistances than their extruded and machined equivalents.
Benefits of CNC Machining & 3D Printing
CNC machining and 3D printing are very different processes and each method offers its own particular benefits, depending on the application.
3D Printing Benefits
- Fast turn-around.3D printed parts have very little set up and custom programming to operate and as such a small batch of parts can ship within 2-3 business days.
- Cleaner production.3D printing is an overall cleaner process than CNC machining.
- Reduced waste.Since it is an additive process, 3D printing produces notably less energy and material waste. Most of which comes from supportive materials used in the printing process.
- 3D printing can create extremely complex parts. Since complicated geometries are built in rather than cut out no tooling needs to reach internal features expanding the potential complexity of printed parts.
CNC Machining Benefits
- Quick production.CNC machining is a much faster production process than 3D printing, especially for higher-volume production.
- Material versatility. CNC machining can be used to fabricate parts from a much wider range of materials.
- Part durability.Material versatility means that CNC machining can produce parts from much stronger and more durable materials.
- Superior precision. CNC machining offers exceptional precision and accuracy when compared with 3D printing.
- CNC machining is easily customized for special parts and components.
While 3D printing may be useful for small batches, prototypes, or parts that do not require a great deal of precision or strength, CNC machining remains a superior manufacturing method for most production runs. The CNC machining process is faster, more versatile, more precise, and more easily customized than 3D printing.
Pro-Type Industries CNC Machining Services
At Pro-Type Industries, we provide high-quality CNC machining services for a wide variety of industries and applications. With almost 50 years of experience in fabrication and manufacturing, Pro-Type has built an international reputation for superior manufacturing. For more information on our exceptional CNC machining capabilities, contact us today.
Computer Numerical Control (CNC) machining has become increasingly common in manufacturing. CNC technology offers a versatile, automated means to produce large-volume runs of high-quality parts. The high levels of accuracy and repeatability offered by CNC machining processes make it an ideal tool for most manufacturers.
What is CNC Machining?
In general, CNC machining refers to one of many reductive processes that take material away from a workpiece to fulfill a design. CNC processes use computerized controls to handle the entire machining process from start to finish, ultimately producing consistently precise parts. CNC machining equipment can follow the same sets of instructions over and over again to facilitate small or large production runs of identical pieces.
CNC machines come in multiple varieties and levels of complexity. Some machines can hold multiple tools at the time or work along X, Y, and Z axes to remove excess material from any side or at any angle.
CNC machining is used to create parts and components for almost every industry and application. This includes the aerospace industry and other highly complex industries that need machining work on large parts. Manufacturers can use this process on substrates such as:
- Composite materials
CNC machining is particularly advantageous due to its automated functionality. Automation allows the machines to operate self-sufficiently, requiring less human labor to produce accurate parts. A growing industry shortage of skilled machinists and laborers has been a primary contributor to the advancement of CNC technology in recent years.
The Three Manufacturing Processes
Generally speaking, there are three types of manufacturing processes:
- Reductive. Reductive or subtractive processes like machining take material away from a workpiece to create a design.
- Additive. Additive manufacturing processes combine or assemble different elements together to create a finished product. 3D printing is the most common form of additive manufacturing.
- Formative. Formative manufacturing bends or otherwise changes the form of the substrate to match the design requirements. Formative manufacturing includes processes like injection molding, in which the substrate is melted and then pressed in a mold to hold a certain shape. It also includes many metal forming processes, such as bending or rolling.
CNC Machining Process Overview
The predecessor to CNC machining—numerical control (NC) machining—used punched tape cards and rudimentary commands. CNC machining follows more complex commands and uses a greater variety of controls. These systems both instruct the cutting and forming tools that remove, but CNC machining equipment can follow complex, customized sets of instructions that come from complex CAD or CAM designs.
Different CNC machining equipment can handle different tools, capabilities, and operations. The CNC machining process typically includes these general steps:
1. Designing the CAD Model
Before the CNC machining process starts, manufacturers need to create the product design. Computer-aided design (CAD) software can be used to create detailed two-dimensional (2D) or three-dimensional (3D) models. These design files include details such as the geometries, dimensions, and other technical specifications of the parts. CAD software accounts for the limitations of machining processes and the properties of the selected materials.
For example, if a design contains holes formed by cylindrical tools, CAD software can inform design engineers when designs are too complex for a given substrate or identify potential problems due to limitations in the selected process. These automated checks help CAD/CAM design services and engineers avoid many potential errors during the rendering process so the prototyping stage is more efficient.
2. Converting CAD Files to Usable CNC Instructions
Once the design is complete, the design specifications need to be translated into directions that CNC machines can follow. The CAD files are run through computer-aided manufacturing (CAM) software. These programs create the programming code that CNC machines use to direct the tools during the manufacturing process. This software also pulls out information about the part geometry that operators can use to ensure the initial workpiece has the right dimensions and orientation.
These CNC-compatible sets of instructions are generally in one of two file types: STEP or IGES. They include programming languages such as G-code and M-code, which each handle specific areas of the machine tool’s functionality. G-code operations focus on the actual operation of the tools, such as their speed, the direction of movement, and how far they move. M-code operations focus on miscellaneous operations, such as powering on and off and other auxiliary functions.
3. Preparing the CNC Machine
Human operators play a much smaller role in automated manufacturing than in manual manufacturing, but they still handle important operations that the machinery can’t manage. This includes:
- Loading the CNC program file into the machine
- Adding the workpiece to the machinery spindles or vices so the machine can manipulate the workpiece
- Attaching the specified machining tools
- Inspecting the work area, machine, and workpiece
4. Executing Operations
Once the equipment is prepared and the program starts, the CNC machining equipment executes the steps and conducts machining operations on the workpiece. The program can complete the necessary reductive processes from start to finish without further operator input. Once the instructions have been completed, the part can continue through finishing and packaging processes.
Types of CNC Machining Operations
CNC machining is a very broad category of possible operations and processes. Among CNC machining operations, drilling, milling, and turning are the most common.
Drilling processes use bits with a diameter the same size as the diameter of the desired hole. The machining equipment inserts the spinning drill bit perpendicularly into the workpiece until it drills a hole of a predetermined length. More complex equipment can produce angular holes, and drilling tools can provide capabilities such as:
The milling process removes cuts of material from the workpiece by moving the material against a spinning cutting edge. The tools have multiple cutting points, and each tool spins to provide a sharp cutting surface with a different length and shape. When the workpiece is pressed against milling tools, thin strips or cuts of material are removed from the existing edge. This can create shallow cuts, wide cuts, or flat-bottom cavities to shape the part. Peripheral milling processes may cut deeper to create slots or threads into the piece’s general shape.
Turning processes turn the workpiece instead of the cutting tool. They include cutting processes such as boring, grooving, and facing. They cut excess material off of a workpiece by using single-point cutting tools precisely applied to the rotating workpiece. Turning creates cylindrical parts that have a specified diameter. Turning can create linear features both inside and on the exterior edge of the parts. These features include:
Advantages of CNC Machining
Many manufacturers prefer machining processes because they create parts or components from a single workpiece. CNC machining has several additional advantages. These include:
- Increased productivity. Facilities with CNC machining can produce parts 24/7. The machines may run continuously with little-to-no human intervention. The machines also require less space than workstations or manual machining setups, so a facility with a set square footage can have more machines running simultaneously.
- A high degree of accuracy. CNC machining uses highly detailed programming operations. The machines follow these instructions without allowing any unwanted variation or human error. The parts will be high-quality, precise, and identical. CNC machining can also produce parts with intricate, complex designs.
- Faster project completion. Every CNC machining process starts with a CAD design, so the prototyping process will be much faster. The software catches or prevents many possible design flaws or potential risks with different materials. When the prototyping and testing processes are shortened, products can go from design into production faster. CNC machining instructions can also be modified or replaced quickly, so there is little delay between changes in production runs.
- Cost-effectiveness. CAD file designs and reduced risks of manufacturing errors reduce the per-unit cost of production. CNC machining also requires less human labor, which further reduces the price of manufacturing the products.
CNC Machining from Pro-Type Manufacturing
For customers seeking a complete manufacturing solution, Pro-Type Industries, Incorporated offers a level of value and process flexibility that is unmatched in the industry. We operate a state-of-the-art facility that is equipped with some of the most advanced CNC machining systems available.
These are high-torque, high-RPM systems that deliver precision and productivity all in one package. One example is our 550 mm Toyoda CNC 4-axis horizontal mill. This state of the art system features spindle speeds up to 15,000 RPM delivered through a 30 HP motor. With a 30” work cube and 2400” per minute positioning, it can power through materials such as aluminum, steel, and plastics at high speeds with maximum accuracy. It also allows us to work with hard-to-machine materials such as Inconel, Invar, Monel, and various superalloys.
However, this is only one of our many precision machining systems. We also operate four CNC vertical mills that can accommodate workpieces up to 64” by 32” by 25”, two horizontal mills equipped with multiple pallets, and a high-output CNC lathe with auto bar feed, sub-spindle, and live tooling. In the hands of our team of seasoned machinists, these high-precision machining can deliver tolerances within ±0.0005”. All of these capabilities and resources are augmented by in-house fabrication of all tooling and fixturing, giving us even greater control over productivity.
Through our nearly 50 years as a manufacturer, we have learned that few project requirements consist of machining only. To add even more value to our service offerings, we also provide value-added services such as:
- Complete assembly
- Comprehensive dimensional reports
- Material traceability
All of our work is backed up by a robust ISO 9001 quality management system and culture that extends to every part of our organization.
From a single prototype to high volume blanket orders that span many months or longer, the key to our success is our ability to provide the same level of value and quality regardless of run size or design complexity. To learn more about all of our manufacturing capabilities, or to request a quote, contact us directly.
The term “5-axis machining” refers to CNC machining operations in which the workpiece or machine tool moves along five axes simultaneously. This advanced machining technique allows manufacturers to produce parts with more complex or intricate designs at faster speeds and higher qualities with little additional processing.
5-axis CNC machines operate by moving linearly along the XYZ axes and rotating along two of them. They employ several different axes configurations to perform machining operations, including:
- Head/Head. The table remains stationary while the swivel head rotates along both additional axes.
- Table/Head. The table and the swivel head both rotate along one of the additional axes.
- Table/Table. The table contains both rotational axes while the swivel head moves along the XYZ axes.
As there are three possible axes of rotation (A, B, and C, corresponding to rotation about the X, Y, and Z axes, respectively), 5-axis machines can be further defined by which two are being used:
- Double Swivel Head. The swivel head rotates along the A and C axes.
- Droop Swivel Head. The swivel head rotates along the B and C axes.
- Double Swivel Table. The table rotates along the A and C axes.
- Droop Table. The table rotates along the B and C axes.
- One Swing, One Rotate. The swivel head rotates along one axis while the table rotates along another (often A and C, respectively).
Applications of 5-Axis Machining
5-axis machining finds use across a wide range of industries, especially in applications that require parts with complex geometries and tight tolerances. Some of the industries that commonly employ 5-axis machining include:
- Aerospace. As 5-Axis machining allows for the production of highly complex, precision parts, it is suitable for producing aerospace components. Typical products produced through this technique include turbine blades and valves.
- Automotive. As in the aerospace industry, the automotive industry often requires components with unique shapes and tight tolerance requirements. However, automotive parts—such as housings, caps, and engine parts—are usually produced in even higher volumes.
- Medical. In the medical industry, components must meet strict standards for quality and accuracy, as even the slightest error in a part could put patients at risk. The precision capabilities of the 5-axis machining process make it well suited for medical parts and products, such as those used in scanning equipment, surgical tools, or implants.
- Energy. The energy industry also demands unusual shapes for use in various generation and containment devices. 5-axis machining is more than capable of handling these requirements.
- General industrial. For general industrial applications, manufacturers use 5-axis machining to produce a variety of standard and custom parts and products, including tools and mechanical components.
In general, CNC machining processes handle a diverse range of materials with ease. The 5-axis machining process is no exception. Some of the typical materials used in 5-axis machining operations include:
- Copper and copper alloys
- Refractory alloys
- Stainless steel
Key Benefits of 5-Axis Machining
Compared to other manufacturing methods, such as 3-axis machining or 3D printing, 5-axis offers a number of advantages, such as:
- Greater part design flexibility. The process’s additional axes of motion facilitate the production of more complex and intricate parts. Some manufacturing processes with fewer axes may require more tooling or equipment adjustments to produce the same parts, while others are unable to recreate them.
- Lower labor costs. As there is less need for adjustments during 5-axis machining operations, there is little to no operator involvement required, which reduces the cost of labor per part.
- Better surface finishes. 5-axis machines move more smoothly with less vibration, resulting in better surface finishes.
- Quicker lead times. A 5-axis machine produces a component faster than its 3-axis or 4-axis counterparts, reducing lead time across the board.
Even 3+2 machining, which involves fixing the workpiece in a rotated configuration, offers many of these same benefits for simpler components.
Other advantages of both processes include:
- Efficient use of floor space
- Superior collision avoidance
- Integrated hole drilling capabilities
- Simple machine setup
- Reduced tool wear leading to longer working life
Choose Pro-Type Industries for 5-Axis Machining
Compared to other manufacturing methods, such as 3D printing or 3-axis CNC machining, 5-axis machining offers faster lead times, greater precision and accuracy, and broader design flexibility.
At Pro-Type Industries, we offer advanced CNC machining capabilities for a variety of materials, including standard metals, exotic and precious metals, plastic polymers, and more. Our clientele spans across a broad range of industries, such as aerospace, chemical, electronic, marine, medical, and military.
To learn more about our CNC machining capabilities, including 5-axis machining, or request a quote for your next project, contact our team today.
Sheet metal fabrication is a process of creating volume from flat sheet material for limitless application. It usually involves cutting, forming, rolling, or pressing the sheet metal using special tools to design specifications so that they can be assembled with other components to create finished products. Some of the common industrial and commercial items produced by sheet metal fabrication include:
- Electronics housings
- Hand tools (shovels, rakes, post hole diggers)
- Automotive body panels
- Mounting bracketry
- Construction Equipment
- Exercise equipment
Depending on the requirements of the design and application, there are numerous sheet metal fabrication techniques available, including forming, stamping, punching, rolling, laser cutting, and shearing.
SHEET METAL FORMING
Sheet metal forming is an effective method for producing sheet metal parts in complex three-dimensional shapes using minimal material. The desired shape is achieved through plastic deformation, without the need for machining.
There are two major categories of sheet metal forming: hot and cold forming. Hot forming is when the raw material is manipulated into shape while in a partially liquefied state, this can be achieved through localized heat from a torch, heated tooling, or specialized ovens. This becomes more necessary with thicker materials and more complex shapes. Cold forming is when metal is formed at/near room temperature through use of high tonnage presses and standardized tooling. This is more applicable to thinner materials and less organic shapes.
As is the case in many industries, robotics have been applied to sheet metal forming as a way to increase overall productivity but also to cut down on some of the upfront tooling costs seen in other fabrication methods such as stamping.
SHEET METAL STAMPING
Sheet metal stamping is a forming process that creates three-dimensional shapes through permanent deformation. It employs a mechanical or hydraulic press and a custom designed punch and die set to create stamped parts and is suitable for producing large quantities of high precision metal parts at low costs. However, initial set up costs are often very high and tooling life and maintenance can often lead to hidden costs.
Sheet metal stamping is often used to create metal parts used in the automotive, household appliances, and medical industries.
SHEET METAL PUNCHING
Similar to stamping, sheet metal punching uses heavy machinery and a punch and die assembly to put holes or indents into pieces of sheet metal. As the machine forces the punch component through the metal, it causes the metal underneath the punch to be separated from the rest of the sheet. The cut metal is then collected in a container and saved for future use or recycling. Punching was the primary method for CNC sheet metal cutting for many years before the development of water and laser cutting tools and still specializes in high speed hole application and low-consumable production costs.
It can be used to create specific shapes and designs in finished parts and components, such as vent openings.
SHEET METAL ROLLING
Sheet metal rolling passes the metal through three rollers to shorten one face of the material and elongate the opposite face causing a progressive curvature in the sheet. This can be done to create complete tubes or to roll to a specific profile. More advanced rolling machines are able to form extremely complex tangential profiles with precision and repeatability.
Some products that can be made using this process include lock-seam pipes, welded pipes, and open-butt-joint pipes.
SHEET METAL LASER CUTTING
Laser cutting directs a high-powered laser through optical components to cut sheet metal into custom shapes and designs for industrial and commercial applications. Compared to similar processes, such as plasma cutting, it is more precise and uses less energy, and is suitable for cutting and engraving a variety of metals, including aluminum, copper, and steel.
For thicker material you may need to utilize water jet cutting as most laser cutters are not suitable above 1” thick material.
SHEET METAL SHEARING
Shearing employs a set of upper and lower straight-edge blades to cut flat metal stock—such as aluminum, brass, bronze, and stainless steel—into separate pieces. The blades are typically offset from each other with the upper blade angled to facilitate the cutting operation.
This process is usually used to cut sheet metal into smaller sizes to prepare it for further processing, rapid prototyping of very simple parts, or commonly in A/C duct manufacturing.
There are many different techniques used in sheet metal fabrication, including stamping, punching, rolling, and shearing. Each technique has a distinct purpose and is used to create different shapes and components, which often require additional finishing and treatment processes following fabrication.
Pro-Type Industries, Inc. has been committed to providing customers with precision sheet metal fabrication services since 1969. Our team has the experience and expertise needed to get your job done properly and promptly. These qualities, combined with some of the most advanced metal fabrication equipment around, allow us to provide you with exceptional quality at low prices.
Contact us today to learn more about how we can help you with your fabrication needs or request a quote.
Manufacturers use Computer Numerical Controlled (CNC) milling techniques to produce complex components in a fast and cost-effective manner. CNC machining controls rotating cutting tools via a computer programming interface. Following the program design, these tools systematically shape the source material into a customized finished product.
A number of common materials can be used in these processes, including:
- Stainless Steel
- Mechanical plastics (UHMW, Ultem, Acetal, Polycarbonate, Nylon, etc)
- Resins (fiberglass, carbon fiber, etc)
CNC milling facilitates the creation of highly accurate custom products from a variety of hard and soft production materials. The rotating tools, driven by their computerized instructions, progressively shave away, cut, and drill the material to create holes, slots, shapes, and other features required by the design.
There are four essential steps in CNC milling:
- Design. Using Computer Aided Design (CAD) modeling, engineers create visual representations of the desired end product.
- Conversion. CAD models are converted to Computer Aided Manufacturing (CAM) files, which instruct CNC machines on the necessary operations to realize the design.
- Set up. The machinery is set up to accept the programmed instructions and install the appropriate tooling so milling can begin.
- Operate. The CNC machine follows the program instructions, parts are inspected throughout production to ensure accurate finished products.
Throughout the process, engineers may adjust the programming to fit new parameters, implement improvements, or respond to unexpected situations.
CNC Milling Advantages
CNC milling offers a number of important benefits to manufacturers in different industries.
- Precision and uniform results. Five-axis CNC milling machines offer a high degree of accessibility and complexity, while minimizing fixturing requirements.
- High-volume production and scalability. After the initial set up, CNC milling machines can produce large numbers of components quickly. After programs have been optimized, the only way to scale machining production is through either additional milling centers, extending spindle hours per day via additional shifts, or through automation and lights-off tooling.
Labor costs are lower than manual milling, but this isn’t a good argument for CNC machining in this era. CNC Machining is one of the most expensive manufacturing methods and commands high hourly pay rates.With CNC milling, manufacturers make more products in less time with less risk of variation from the original design. There are plenty of new technologies that support variation mitigation, tool probes, dynamic offsets, in-tool diagnostics and vibration dampening, thermal indicators to reduce tool wear and heat warpage in parts, automated loading and unloading via robotics, and a long line of things.
CNC Milling Services
There are a number of choices for CNC milling operations. Each type has its own unique advantages and applications.
- Face milling employs a tool with teeth on both the periphery and face. This tool is used to make flat surfaces, smooth contours, and produce a higher quality finish than other shaping methods.
- Plain milling allows the shaping of large pieces of material. Wide cutting teeth allow the shaping of large areas of material while their narrower counterparts make deeper cuts.
- Angular milling adjusts the angle of cutters to produce chamfers, serrations, grooves, and other angular features.
- Form milling uses formed cutters to craft circular cavities, contours, and intricate patterns.
- Straddle milling is the process of cutting multiple pieces with one machine. Cutters are attached by an arbor and move simultaneously across adjacent surfaces.
- Gang milling uses multiple cutters on one machine arbor. These cutting tools are able to perform the same actions, creating complex parts in less time.
- Profile milling refers to the process of cutting vertical or angled pathways across the workpiece.
- This section seems to only have words that would come up if you googled “types of milling” but doesn’t seem to align with “choices for CNC milling operations” that is in the header. Drill, bore, ream, step/ramp mill, thread mill, tap, 3D contouring, swarf, high speed machining (constant engagement), are just some of the common operations.
There are also different types of CNC milling machines. Which machine is appropriate depends on the complexity and details of the design.
- A vertical mill orients the spindle axis vertically. This allows easier cutting and drilling of some materials.
- Horizontal mills operate on a flat, level plane. These devices are better for shaving and cutting.
- A turret mill features a stationary spindle on a table that can move in both perpendicular and parallel directions. These machines are highly versatile for their compact size.
- Bed mills are similar to turret mills. However, the tables on these machines only move in a perpendicular direction.
There are a number of components that make up CNC milling machines:
- Machine interface
- Machine tool
Each of these components is a vital part of producing parts. CNC milling is an integral process in the manufacture of a wide range of products—far too many to list here. Examples include:
- Car Engines
- Industrial equipment
- Aerospace components
- Musical instruments
- Cell phones
- Consumer products
- Die making for injection molding/casting
CNC milling is a flexible method for producing highly customized components quickly, accurately, that avoids high initial tooling costs for production. Find out what CNC machining services from Pro-Type Industries can help your company save time, money, and frustration in your production processes.