3-Axis CNC machine or 4-Axis CNC machine How to Choose?

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3-Axis CNC machine or 4-Axis CNC machine How to Choose?

Nov 30, 2022

3-Axis CNC machine or 4-Axis CNC machine How to Choose?

These days, product teams have lots of options when it comes to multi-axis machining, from 3-axis CNC machine to 5-axis CNC machine to even 9-axis machining. What’s the difference between each type? In this article, we’ll break down the key similarities and differences between two popular types of CNC machining (3-axis CNC machine vs. 4-axis CNC machine) — and explain when it might make sense to use one over the

What is 3-axis CNC machining?

After the operator enters milling instructions into a computer, the 3-axis CNC machine will automatically complete the task by using a tool to cut along three axes — X, Y, and Z, or left-to-right, front-to-back, and up-and-down. Both CNC milling and CNC turning fall under the umbrella of 3-axis machining. However, they function slightly differently.

When using a 3-axis CNC milling machine, the material block remains fixed in a vice or on a machine bed. Rotating drills or cutting tools are connected to a spindle and move along the X, Y, and Z axes, removing shavings to accurately form the final component. 3-axis CNC milling machines are excellent for producing most geometries and simple parts.

How to calculate the cost of 3 axis machining?

The cost of machining is determined by the machine used. Three-axis machines and multi-axis machines are the two most common types of CNC machining machines. The 3-axis machines in Europe cost roughly $35-$40 per hour, whereas the multi-axis machines cost between $75-$120 per hour on the European market. You can get 3-axis machines for as little as $8-$10 and 5-axis machines for as little as $30 from Chinese companies like LEADRP.

Machining costs are affected by two factors: machine pricing and the number of hours a machine is scheduled to run in a year (which is 5000 hours on average). Machinists calculate their machine shop rates by dividing the machine’s cost by the number of hours it will be used in a year (also known as the machining cost per hour).

3 axis CNC machining 5 commonly used materials

1. Aluminum

Aluminum alloys are easy to machine in large volumes, have a good strength-to-weight ratio, and high thermal and electrical conductivity. They are also naturally resistant to corrosion. Aluminum 6061 is an all-purpose aluminum alloy often used for CNC machining. It is typically found in automotive parts, bike parts, sporting goods, and other recreational items. This material is highly machinable; however, it can be pricier than other metals and doesn’t hold up well in the presence of saltwater or certain chemicals. Aluminum 7075 is a step up from 6061. Ideal for aerospace frames and high-performance recreational equipment, it’s the strongest commercially available aluminum alloy.

2. Stainless steel

Stainless steel alloys are strong and resistant to distortion, wear, and corrosion. 303 stainless steel includes sulfur for improved machinability, but this material has a number of limitations that engineers must keep in mind.

303 cannot be cold-formed, heat-treated, or welded, and special care must be taken with speed/feeds and the sharpness of cutting tools during CNC manufacturing. That said, 303 makes excellent nuts, bolts, non-marine grade fittings, shafts, and gears.

304 stainless steel is a non-magnetic, all-purpose steel for CNC machining known for its toughness. It’s readily machinable and corrosion-resistant like 303, but it can be welded. 304 is well-suited for a wide range of consumer and industrial applications, kitchen accessories, tanks and pipes, architecture, and more. 316 stainless steel is even more corrosion-resistant than 304 or 303 thanks to the addition of molybdenum. It’s strong, weldable, and one of the few marine grade stainless steels.

Since it’s impossible to tell stainless steels apart by sight alone, engineers should make sure to test the raw material to confirm the characteristics of the steel they’re using.

3. Carbon steel

Carbon steel 1045 is a mild grade of carbon steel. Manufacturers often machine with this material because it is less expensive than most stainless steels but stronger and tougher. 1045 is easy to machine, weldable, and can be hardened or heat-treated to achieve various hardnesses.

This material is ideal for nuts, bolts, gears, shafts, connecting rods, and other strong, small mechanical parts. 1045 can also be used for architectural applications, but it must be surface-treated to prevent rust and corrosion.

4. Titanium

Known for its high strength, toughness, and corrosion resistance, titanium is often employed to manufacture parts for the most demanding aerospace, military, and industrial applications. This material is also biocompatible and suitable for use in medical device manufacturing.

However, titanium is more expensive than any other metal in its commercial form, doesn’t polish well, and is a poor conductor of electricity. Engineers should also be aware that titanium is challenging to machine, and requires special cutters.

5. Nylon

Nylon is an all-purpose, low-friction thermoplastic that is often used as an alternative to metal in CNC-manufactured parts. This material is stiff, strong, impact-resistant, chemical-resistant, but surprisingly elastic. Nylon responds well to additives and fillers, so engineers can feel free to manipulate this material to achieve their desired properties.

Popular applications for nylon include electrical molding, fuel system components, gears, food packaging, fabric, and more. However, nylon absorbs moisture easily, which may negatively impact the dimensional stability of a part.

3 axis CNC machining application industry

Some manufacturers may have their own machines to make the products they need. Different machines use varying techniques to work with different materials based on what each sector needs for its parts. Other companies decide to work with professional CNC machining businesses to make their parts.

By using the right machine and material for the job, CNC machinists can serve a wide range of industries. Each of these industries has its own needs, which means not all uses of CNC machining will work for every business. Even companies within the same industry may find different applications for CNC machining in their niches.

1. Medical Industry

2. Aerospace Industry

3. Transportation Industry

4. Oil and Gas Industry

5. Military and Defense Industry

6. Electronics Industry

7. Marine Industry

3 Advantages and disadvantages of axis machining

By contrast, in the CNC turning process, the workpiece is attached to a rotating spindle, and a lathe shapes the component. As the spindle holding the workpiece rotates, a center drill or cutting tool traces the component’s outer and inner perimeters or creates holes along the center axis. Compared to CNC milling machines, CNC lathe turning machines produce parts faster and offer cheaper per-unit costs, which is advantageous for high-volume production runs.

Since a 3-axis CNC machine can only cut along three axes, it may struggle with non-conventional shapes or designs with deep, narrow cavities that are difficult to reach. When processing parts with complex geometries, operators may have to manually reposition the workpiece, which can slow down the processing speed, raise labor and machining expenses, and result in a less-than-perfect finished product.

What is 4 axis CNC machine?

4-axis machining has evolved from the most common type of CNC machines working with 3-axis technology. In comparison, 3-axis machining is limited to move the spindle on three linear axes (X, Y, and Z). 4-axis machining, on the other hand, can rotate on one axis and open up to more complex operations in one setup. The rotation is made possible by the 4-axis, which allows rotation on the x-axis.  And it enables the workpiece to rotate during machining. It is, therefore, feasible to machine four sides of the part in one single fixture setup.

4-axis machining has paved the way for high-precision machining and offers more precision and accuracy than a conventional CNC machine using 3-axis technology. Many parts- and component manufacturers within the automotive and aerospace industry and other areas have upgraded to a 4-axis machining center to produce more complex designs in one machine within a setup.

This upgrade is an effective way to increase productivity, saving both time and money. But what does 4-axis machining mean, and what differentiates it from 3- axis and 5-axis machining? We will clarify everything about 4-axis machining and highlight the 4 axis machining solutions Jamesli offers.


Multi-axis machines have many advantages over standard CNC machines using 3-axis machining technology. Here we shed light on the most important benefits of 4-axis machining.

Greater Accuracy

Four-axis CNC machines offer multiple faces without transferring the piece from a fixture, making exact capabilities. This degree of precision results in less litter and also a rise in earnings.

Attain Complexity in Part Designs

The most typical reason to use a 4-axis machining center is to manufacture complex parts and components. Four-axis machines, built for comprehensive function, can access peculiar angles without design complex fixturing.

Faster production time

A 4-axis machining center reduces the cycle time because the machine is performing collective processes in one setup. A 4-axis machining center does not have to be stopped to turn the part of the fixture, which means no downtime to change tools or have an operator rotate the component manually.

What can you make with a 4 axis CNC router?

Four-axis CNC machines can be used for different purposes, including creating art, medical equipment, advertising design, teaching, technology research, industrial parts, prototype building and more.

How to calculate the machining cost of 4 axis cnc

The quotation problem of machining is a more complicated problem. The main factors are as follows:

  1. processing batch problems, single and large quantities of prices may vary greatly.

  2. It is the complexity of the workpiece and tolerances, especially the shape tolerance, which is the accuracy level, which has a great impact on the quotation of the workpiece.

  3. It is the local hourly rate, there is also a great relationship; there is the material, is the degree of easy cutting, these factors affect the quotation, so the quotation problem is a comprehensive problem.

Sometimes, when the batch size is large, the price of processing waste is also calculated. If it is a non-ferrous metal, the scrap must be stated in advance, which is not a small income.

Assuming the outer diameter is 18mm, then the outer diameter of the first car needs one knife. Assuming a rotation speed of 120 rpm, and a feed rate of 0.1 mm, then the time for one knife can be calculated to be 24 ÷ (120 × 0.1) is about 2 min (24 = Workpiece 20+ retract width and cutter width);

The second step is the car screw buckle, the M16 thread is 2mm pitch, then the 20 length is 10 turns, plus the tail width is at least 12 laps, according to 60 rpm, it is 0.2 minutes, and each knife is returned for 0.2 minutes. Half of it is 0.1 minutes, add up to the car screw buckle is 0.3 minutes per knife, this thread rough car four-knife fine car is 0.3 × 5 = 1.5 minutes.

The third step is to cut off, according to 0.1 feed per revolution, 100 rev / min, which is 16 ÷ (100 × 0.1) = 1.6 minutes

The above working hours are 2+1.5+1.6=5.1 minutes.

If it is a single piece, add auxiliary time 30 minutes = 35.1 minutes

In batches, it is appropriate to add a certain amount of man-hours according to the batch size. For example, 500 pieces can be given for 6 minutes.

Down is the hourly rate, calculated by CNC 30 yuan / hour

Single piece 35.1 × (30 ÷ 60) = 17.55 yuan / piece

Batch 500 pieces: 6 × (30 ÷ 60) = 3 yuan / piece

The above is only to explain the calculation method and related problems, does not represent the real price, and can be re-verified according to the actual situation.

3-axis machining vs. 4-axis machining

When choosing a CNC machining center, how many axes do you need for the CNC milling machine? It’s a tricky question for every CNC mill purchaser, therefore, let’s shortly enter the differences between 3-axis, 4-axis, and 5-axis machining.

3-axis machining

3-axis machining is the most straightforward type of machining, where the workpiece is fixed in one position. The spindle can move over three linear axis X, Y, and Z. In other words, the spindle can move back and forth to left and right and up and down. For some machined components, this is a perfectly appropriate way to get the job done. 3-axis machining is suitable for parts that don’t demand a great deal of detail and depth. And it is most commonly utilized to create mechanical parts and is best suited for automatic/interactive performance, milling slots, drilling pockets, cutting sharp borders. With 3-axis machining, the cutting tool’s angle remains uniform, pointing sideways or downwards, making it more difficult to cut away portions of the substance in hard-to-reach segments of the workpiece, such as crevices.

In a 3-axis machining center, it may be necessary to make several settings for one part. If the component needs to be machined on several sides, it may need to be removed from the unit, redirected, then returned to the machine for further cutting. Multiple settings’ requirements can drastically reduce productivity. Using 4-axis or 5-axis machining can decrease the number of setups needed and let you do more complex machining without adjustments and stops, thereby increasing your productivity.

4-axis machining

With 4-axis machining adding rotation to the three linear axis X, Y and Z,  it is possible to process more than one side of the workpiece in one setup. Using a 4-axis machining center instead of a 3-axis machining center decreases the number of setups and readily manages multi-sided pieces. A 4-axis machining center is perfect if you require high quality and a precise result and can, for example, be used for intermittent cutting, continuous cutting, engraving curved surfaces.

Work with us

Still hesitant about using a 4-axis CNC machine or a 3-axis CNC machine? Jamesli can help. Our team of experts can discuss CNC machining options with you and help you choose the best process for your project. As a trusted CNC machining partner, Jamesli also provides high quality CNC machining capabilities, including CNC machining equipment based on routers, lathes, drills and milling machines. Contact us today to get started.