Routing is a Computer Numerical Control (CNC) process or tool to shape wood, plastics, and soft metals. The computer control of CNC routing can precisely cut, drill, and engrave these materials into intended parts. Moreover, its rapid material removal and detail-shaping capabilities are indispensable in specific material-focused applications.
Let’s go through its straightforward breakdown, including what is CNC routing, the routing process, CNC routers, advantages, applications, limitations, and more.
The first question in your head could be what is CNC routing? It is one of the popular machining approaches in modern manufacturing. Like other standard CNC machining, routing refers to shaping compatible materials into the desired shape or geometry. However, the difference is in tooling and capabilities.
The routing machine uses a specialized tool called a router with a rotating bit. This router moves across the workpiece following the instruction (G-code) and pre-determined tool paths to shape to perform the machining operations. Furthermore, it involves a large CNC bed and low tool pressure. As a result, routing operations are suitable for thin and large worksheets.
The machine involves a bed table to hold the material and a spindle to hold the CNC router bit. First, G-codes are sent into the CNC controller, and the bit goes to the initial cutting position. At the same time, the operator sets the machining parameters, such as cutting depth, spindle speed, etc. Next, the spindle moves on multiple axes to remove the material and create the desired shape, generally the X-horizontal, Y-vertical, and Z-height.
Here, you might wonder how the router machine controls the spindle. The spindle is connected to several motors and linear guides. As the G-codes are uploaded, the controller converts to electrical signals that control these motors and guides.
Here is the Step-by-Step process of CNC routing:
- 3D Modeling: This is the first step. The designer created a detailed model with all specifications, features, and tolerances.
- G-code: The G-codes are obtained by processing the 3D model into CAM software. It contains all the machining information.
- Machine Setting: In machine setup, appropriate machine tools and CNC router bits are necessary for desired results. Likewise, securing the workpiece in the machine bed.
- Zero-Positioning: The router bit is set at the starting position (0, 0, 0 referencing).
- Machining: The routing bit rotates at high RPM and starts to remove the material across the predetermined path.
- Monitoring: The machining goes until the final shape. So, the process remains under observation for possible tool wear, precision deflection, and other defects.
- Surface Finishing: Further finishing, such as sandblasting, deburring, and brushing is applied if the as-machined finish is not enough for functionality or aesthetics.
- Quality Control: Final inspections and measurements ensure that parts meet the desired specifications and standards.
A CNC router is an intricate machinery. It consists of various components, each with a unique role and function. The cumulative action of these components completes the CNC routing process.
The following are the six major components:
1. Frame and Gantry
The frame is typically a stand with legs made of high-grade aluminum or steel. It resists the cutting force and damps the vibrations, providing rigidity and stability to the machine. Similarly, the gantry structurally supports spindle and cutting head movements.
2. Table or Bed
They are flat surfaces with T-slots or vacuum hold-down systems, which allow clamps and fixtures. Thus, tables or beds are responsible for placing and holding workpieces securely for machining. Additionally, beds also contain tool-path sensors or occasionally spoil boards of MDF.
It is the components that provide the necessary cutting force during CNC routing. Fundamentally, the spindle is a rotating shaft connected with several motors, bearings, and guidance systems for motion control. It also contains a collet or chuck to hold the cutting tools, such as router bits that rotate and move with the spindle. Subsequently, it can rotate at a speed of 10,000-20,000 rpm.
4. Cutting Tools
The router machine allows the use of different cutting tools to achieve complex shapes and unique machining needs. Some routing kits involve V-bits, ball & nose cutters, drill bits, straight & flush-trim bits, Spoilboard surfacer, etc.
Each of these tools varieties have distinct machining uses. For example, straight bits are suitable for straight cuts and grooves, while V-bits are for engraving applications.
5. Axis Motors
As we know, the spindle moves along multiple axes for routing operations. Hence, axis motors facilitate this by their precise coordinates and movement control. You can find two types of motors used in axis drive: servo and stepper motors.
Servo motors move the gantry and the spindle motor toward their guide rails based on g-code instructions. They use feedback to adjust speed and position continually. In contrast, the stepper is simpler and moves in discrete steps to control position and speed. Likewise, a rack and pinion system is attached along the longer axis, allowing the spindle or gantry to move along the X and Y axes.
6. CNC Controller
A CNC controller is an electronic component of CNC routing machinery. It consists of a control processor (CPU), storage (RAM), input & output ports, and a drive circuit. This controller receives the g-codes and executes by sending the electrical signal to the motors. Therefore, motors (and ultimately the spindle) move by following the controller signals.
There are several types of CNC router machines based on size, capabilities, and specific machining applications. Even though, here we will discuss the three major types: Industrial, Desktop, and Multi-axis routers.
Industrial routers are suitable for heavy-duty manufacturing because of high-power spindles. These are the large and sturdy build machines that handle intensive routing projects. Also, they require more floor space than the hobby router or desktop router. Furthermore, industrial routers are essential in woodworking, metal fabrication, aerospace, automotive, and marine for fast and accurate machining of various parts.
Desktop routers are efficient and powerful CNC machines that can move three or more axes. But, they are small and designed for space efficiency and ease of use. These routers cannot handle heavy industrial routing due to capability limitations. However, a desktop CNC router is ideal for small businesses, house workshops, and DIY router enthusiasts.
Multi-Axis CNC Routers
For complex machining, there are routers with different axis capabilities. These machines have 3, 4, or 5-axis movement abilities, even more than 5 in some cases. As the number of axis movements increases, machines can create more complex and accurate parts. Nevertheless, the choice depends on complexity, tolerances, and workpiece material.
The first significant advantage of CNC routing is fast and accurate machining for soft materials. Let’s discuss straightforward benefits and limitations.
- It can achieve a precision of approximately ± 0.0025mm and is far ahead of traditional handheld routers.
- The large size of the router bed allows the machining of large sheets or workpieces.
- Advanced tooling like ATC routers allows for automatic change of CNC router bits during operation, reducing the cycle time.
- Routing offers excellent repeatability. It can create identical complex shapes consistently.
- It is cost-effective and can create complex shapes from compatible CNC materials.
- The CNC router machine has some limitations also. It cannot machine hard materials like steel and titanium.
- The CNC bed size limits the workpiece size, and design change demands too much time.
- The router machine can be loud due to its vacuum system.
Since routing is a preferred machining process for soft materials, you might think it is compatible with fewer CNC machining material options. On the contrary, the router can machine diverse plastics, woods, and some composites & metals. It is only unsuitable for metal and alloys with high hardness.
The following are the materials for the routing process.
- Woods(soft, hard, and, ply)
- High Density Polyethylene(HDPE)
- Acrylonitrile Butadiene Styrene(ABS)
- Polyvinyl Chloride(PVC)
- Aluminium and its alloys(2024, 6061, 6062, 7075, etc)
The advanced machining capabilities and diverse material range make the CNC routing process applicable in many sectors, such as CNC wood mill, metal shape & engraving, signage, mold making, etc.
It makes intricate furniture and custom carpentry in woodworking, 3D signage, and engraved plaques for businesses and events. Subsequently, musical instruments use CNC router parts, such as guitar bodies and drum shells. In automotive and aerospace, it is a popular method for rapid prototyping of several components.
Furthermore, router parts are also valuable in making molds, architectural models, circuit boards, marine applications, jigs & fixtures, electronic enclosures, etc.
|A spindle moves along the X, Y, and Z axes with a rotating router bit that removes the material.
|The spindle moves along multiple axes (3 or more) with a cutting tool with high cutting force for materials removal.
|Routing machines are less rigid than milling.
|The robust frame and structure of CNC milling machines make them highly rigid.
|CNC routing machine operates at High speed.
|Lower to moderate cutting speeds
|Wood, plastics, foam, and some soft metals and composites.
|Almost every CNC material, from plastic to hard metal and alloys.
|Low to medium cutting forces
|High cutting forces
|Excellent precision in material-specific machining with a tolerance of as low as ± 0.0025mm.
|More than routing, tight tolerances for complex and detailed designs.
|More suitable for large-scale machining rather than complexity.
|Milling handles complex and detailed projects.
|Straight bits, flush trim bits, round-over bits, V-grooves, etc.
|Diverse machine tool options than routing, end mills, face mills, drills, chamfer tools, ball nose cutters, etc.
|Expensive than routing
The router and spindle both serve a similar purpose. However, they have differences in performance and applications. The spindle operates at high torque and low cutting speed. Conversely, routing involves low torque and very high cutting speed. Next, the runout of a spindle is 0.0002 inches or lower, while it ranges from 0.0010 to 0.0015 inches for a router. Source.
The router is applicable in the creation of furniture, engravings, art, plastic & soft metal parts, and prototypes. On the other hand, the high-speed spindle is a better choice for heavy-duty industrial applications. Thus, choosing between router vs. spindle requires consideration of some selection criteria. These criteria are workpiece material, precision, complexity, cost, operational volume, etc.
Starting the CNC routing involves careful execution of several steps. Before starting, you must have a 3D model of the intended part in a compatible format, such as STEP, STL, and DXF. Then, here are the steps chronologically:
- Activate the CNC controller, remote control, bed/ table, and dust collector.
- Choose the appropriate CNC router bit and attach it to a collet or chuck.
- Place the workpiece on the table by adjusting the vacuum zones.
- Position the bit on the initial position and make the coordinates 0, 0, 0.
- Insert the CAD/CAM file into the controller and execute the program.
- Monitor the process continuously until the end.
No! You cannot use any router bits for CNC router machines. Which bit to use depends on what is routing going to the machine. Each type of CNC router bit has specific material compatibility and machining capabilities. For example, you can use V-bits for detailed wood engraving, but straight bits cannot achieve this.
Therefore, you should choose the right bit according to the work material and desired results. Otherwise, it affects the tolerance, speed, and surface finish. Sometimes, wrong tooling can also damage the workpiece and tool itself. Here, it is best to seek consultation from an expert to choose the right router bit for any particular project.
The CNC router work converts the designs into physical parts with exact specifications. It offers precision and cost-effectiveness with the machining of any appropriate material. However, choosing the right tools and parameters, using advanced equipment, and operator skills decide the final result.
RapidDirect has advanced machinery and expertise to handle any design of CNC routing. We provide all CNC machining services across different industries. Our reliable services range from rapid prototyping to mass production of industrial and customized parts. Our experienced engineers work closely to ensure we can exceed the client’s expectations. So, if you need CNC routing or similar services, you can request a quote for our precise yet affordable CNC machining solutions.