Horizontal vs. Vertical Milling – Understanding Key Similarities and Differences

“The integration of CNC in milling machines has advanced the milling techniques for effectiveness and perfection. These machines cut, carve, and shape from basic components to functional prototypes. ’’

The CNC milling operation enables machinists to automate cut, carve, and shape from a wide array of plastic to metal materials for their intended use application. In this way, horizontal and vertical machinings are brought to practicality. Both are subtractive manufacturing techniques that help remove unwanted material from a workpiece in multiple orientations and dimensions. Moreover, inch precision, reliability, optimal accuracy, and the ability to meet tighter tolerances are key features of these fabrication machines.

This blog entails the operational differences and similarities such as what are vertical milling machines alongside their intended uses across manufacturing industries, and so more to know about. 

A Brief Overview of Milling Machines

Assembly Parts of the Milling Machine

CNC Milling machines are so widespread, because of their smooth performance and inch precision in machining operations. Milling machines equipped with three identical components to perform cutting options on material surfaces; including

• Spindle: Holds the cutter, normally oriented along the axial direction of the move or feed.
• Worktable: Support the job material (workpiece).
• Cutting Tools: Perform cutting operation along the axis (3, 4, 5-axis) for optimal cutting throughputs. These tools are positioned longitudinal or transverse to the feed or move.

These machines meticulously shape and carve metals, and plastic materials for industrial use components. Moreover, multiple heads could be installed on a machine part to process more than one part at once. 

Related To: 3-Axis V.s 5-Axis CNC Machines

What is a Vertical Milling Machine?

Vertical milling machines are widely used across industries. This machine is equipped with a rotating cutting spindle which is mounted vertically, and multi-functional tools. These tools rotate around the stationary workpiece to carve out imperfections from the workpiece. 

Sometimes, for workpieces with irregular geometries, the process of facing, which is one of the Six Major CNC Milling Techniques, is used for uniform geometric shapes all over the object’s surface. Vertical milling machines contain two types of setups that manufacturers implement as per their design requirements. 

• Turret: Turret is recommended for refining small geometries. The setup contains a spindle (the rotating tool) that remains stationary, while the turret (a moveable) performs milling operation on job material, both in vertical and horizontal orientations.
• Bed Milling: In bed milling machines, especially the traditional ones, the spindle moves vertically while the bed moves to the horizontal alignment. This combination of movements helps cut the workpiece, creating bores, and grooves.

What Are Vertical Milling Machines Used For?

Vertical milling machines refer to workhorses because they offer exceptional torque and speedy machining. The controls of the vertical milling machines are mixed. They can be calibrated manually or through automated systems CNC (Computer Numerical Controlled). The rotary cutter on the spindle typically removes the stock material from the workpiece in shorter lead times. A drill press is a moveable table across which the vertical spindle moves, and in turret milling, it provides even greater machining control. Here’s a short breakdown of its benefits:

• Vertical machines feature long and thin tools.
• Grooving and slotting functions are easier to achieve through vertical mills.

What is a Horizontal Milling Machine?

Horizontal milling machines work on a different mechanism. In this type, the basic operation is identical to vertical milling machines. The rotating tool and workpieces are stationary. The difference comes in the orientation of the cutting tool that is placed horizontally. These milling systems are more prevalent in the industry than vertical milling machines. 

Horizontal millings are generally preferred for cutting deeper cuts. The horizontal cutting tool is designed for highly forceful impact. The precision is generally lower as the tool rotation causes powerful cuts on the workpiece. However, the integration of advanced CNC technologies has eradicated these downsides of vertical machines.

Some of its core advantages are discussed below:

• High performance, and functionality for intricate designs.
• Feature short and thick tools to remove excessive material from the object.
• Typically, horizontal machines use saw blades (disc-shaped cutters) for milling. 

What are Horizontal Milling Machines Used For?

Horizontal milling machines are generally good for deeper holes and smooth surface finishes. These machines offer the quickest milling operation. For instance, 3-axis milling has a tolerance value of ± 0.005 inches (0.13 mm). 

CNC-milled part

For 5-axis milling and engraving of workpieces, the tolerances can vary but the general value remains the same. Other milling operations such as routers (cutting gaskets) have a tolerance of ±0.030 inches (0.762mm). In addition to their applications, horizontal machines dictate various key components for the aerospace industry, examples of a few are given below;

• Avionic systems
• Intricate engine components
• Performance aircraft structures
• Complex shape Internal metallic parts
• Aerodynamic components

Additionally, the applications across automotive sectors are; Gearboxes, Engine blocks, Electric motor stator housing, Axels, etc.

Horizontal vs. Vertical Milling Machines – A Comparison

Horizontal Vs. Vertical milling Machines

The prime function of both mills is to cut and shape materials to the desired configuration. The differences lie in their assembly and the way of performing cutting or shearing. Let’s figure out some of the core differences between horizontal vs. vertical machines.

1. Spindle Orientation 

The core difference lies in the orientation of the spindle. It is a primary tool of the machine which dictates the cutter to operate on the workpiece. The orientation of the spindle is different in horizontal and vertical milling machines. The vertical spindle orientation helps in precision cutting while the horizontal is used for depth cutting across large workpieces. 

2. Tool Geometry 

Geometry in tools of both horizontal and vertical milling machines is different. For instance, the spindle head, collet chuck, slot drill, and end mill components of both machines are geometrically different. Vertical milling machines possess a cylindrical system that is both thin and long. In contrast, horizontal ones have tools with heavier design geometry. These specifications impact the accuracy of each machine.  

3. Accuracy

What are vertical machines used for? As the machines are built with different geometries, the vertical tools offer more accuracy. For instance, when carving out details in the workpiece, vertical machines are spot on as the spindle and cutter are lightweight which results in a more precise impact.

4. Machine Cost

Horizontal vs vertical milling machines have different costs. Horizontal milling machines are used for heavy cuts(chamfering, or facing, etc) which makes them an expensive option compared to vertical milling machines. In contrast, vertical milling machines are easier to maintain and simple to operate. This is why small-scale manufacturers can implement vertical mills in their businesses. Moreover, horizontal milling machines require expert operators to facilitate the smooth handling of the cutting operations. Nevertheless, both machines are equally important and their usage depends on the type of product and industry requirements. 

5. Rate of Working

The time constraint is also an important factor to consider. The horizontal milling machines take the lead in this regard, as they offer high stability and produce deeper cuts at a high rate. Vertical milling machines are used for precision and have a limited cutting potential. This makes the removal rate of vertical milling systems relatively lower than horizontal ones. 

CNC Milling Vs. CNC Turning: Key Differences

CNC Milling Vs. CNC Turning, both are used interchangeably, but there are clear differences between their operation. CNC milling: In its operation, the workpiece remains stationary, while the cutting tool rotates, to cut, and shape the intended object (workpiece). 

CNC Milling

CNC milling rotates around the 3-axis (X, Y, Z), and is useful for shaping detailed feature parts, functional prototypes, auxiliaries, and non-symmetrical components. Some common examples include; necklaces, interiors, and exteriors of automotive to aerospace components.

The most commonly employed milling machines are;

• Angular (Typical angles ranges are 45°, 50°, 55°, or 60°)
• Face 
• Plain

CNC Turning, on the other hand, is a process in which the job material rotates along the axis of the machine while the tools perform cutting operations. 

CNC Turning

For axially symmetrical, conical, and cylindrical parts, CNC turning is the right fit. Unlike conventional turning machines, CNC turning uses computerized numerical control to carve material into the desired configuration. CNC turning facilitates options such as; 

• Taper Turning
• Straight Turning
• External Grooving
• Knurling
• Threading
• Boring & Drilling

Let’s figure out some critical aspects of CNC milling vs. CNC turning:

Table: CNC Milling Vs. CNC Turning

Which One is the Right Choice for Your Application? Horizontal Vs. Vertical Milling

Choosing the right milling machine comes down to the project requirements and industry specifications. The budget also plays an integral role in this decision. Let’s break down the considerations for both systems for easy decision-making for your next project.

Vertical Milling Machines: 

• Ideal for smaller workpieces, choose only if the object needs detailing and less cutting. For instance, when a cut is required on a single plane.
• For surface polishing and precision cutting projects, make numerous attempts to remove layers at every pass. 
• Feasible for lower investments. Install vertical milling systems if you are planning to set the entire setup at your workshop.

Horizontal Milling Machines:

• Horizontal machines are the go-to choice for large-volume production runs.
• Employed for carving one or more grooves in workpieces at multiple angles.
• Rapid prototyping needs can be fulfilled by using vertical milling machines.
• These machines are useful for creating slots across multiple sides and several planes of the object.
• When you have flexibility in the budget in terms of maintenance and other associated financial prospects.

CNC Milling Services at Prolean

Modern CNC Milling requires expertise with the latest machinery to compete in the market. Dealing with tight tolerance can become a headache for most of the time. This is where prolean steps in. Our technical staff will cooperate with you to achieve even tighter tolerances upto ±0.0002″ (0.005mm).  

CNC Milling Service

From prototyping to large-scale production, we deliver the best services intended for your application requirements. Contact us to hear from our professional experts and get a complete walkthrough for your project. 

Send us your queries for an instant quote!

Read more: 

• Milling machine Vs. Lathe: What’s The Difference?
• Fundamentals of Sheet Metal Cutting Processes
• Best Cutting Tools For CNC Machining

Summing Up 

Horizontal Vs. vertical machines, however, both machines offer dozens of benefits when exploited for medium to large volumes batches. Their suitability to a variety of materials, and inch-precision perfection make them a sound choice among industry professionals. 

However, there are notably few things that need to be considered while selecting out of these two. For example, if you’re concerned about deeper contours or complex detailed parts, you can opt for CNC horizontal machines. While vertical milling machines are good for machining, horizontal systems help in the deeper cutting of heavy materials. The ultimate choice depends on the material dimensions, size, shape, and requirements. By knowing their likenesses and contrasts, you can make an appropriate choice for your specified requirements. 

Moreover, this article contains comprehensive information about the technicalities around CNC machining methods and covers queries like how, and when to choose. and which method costs more. By considering these considerations, you can make a standardized selection based on your project requirements.

FAQs

Q1. What are milling machines used for?

Milling machines are crucial for removing stock materials from a workpiece. They are built with cylindrical tools including drills and end mills that help in flattening irregular surfaces. 

Q2. What are the qualities of an efficient milling machine?

Several factors make efficient milling machines. Firstly, are DROs (digital readouts) that make milling user-friendly. Movement on multiple axes is another factor that enables smooth operation with a greater range of variations. 

Q3. Horizontal Vs. vertical, which machine option is best?

Both machines are versatile in their intended applications. The ultimate choice depends upon certain considerable factors; for instance; budget, timeline, number of planes, and desired geometries.

Q4. How to achieve optimal performance out of these machines?

Optimal performance results in Regular cleaning and maintenance of machining parts as well  the lubrication of rotating components of the machine

Q5. What products are made from milling machines?

Milling machines can help in creating a variety of metallic products including, machine components, car parts, medical tools, and instruments.  

Q6. Which is more expensive? CNC horizontal or vertical machining?

When it comes to financial implications, CNC horizontal machines incur higher initial costs. These machines are laborious and require regular maintenance, laborious, and that lends to higher expenditures. 

Resources 

1. Ariacutty-Jayendran, (1997), The Milling Machine: Retrieved From: Springer
2. Milling machine, general introduction: Retrieved From: Harvard Education