A 3-axis CNC machine is ideal for basic 2D and simple 3D machining, with an accuracy of ±0.01mm and costs around $50,000 to $100,000. A 4-axis CNC machine adds the A-axis for complex parts, achieving ±0.005mm accuracy, and costs around $100,000 to $200,000.
Characteristics of 3-Axis CNC Machines
It is just amazing to see the capabilities of 3-axis CNC machines, especially as these developments have been coming thick and fast in recent times. Here are the main features of 3-axis CNC machines explained. These machines generally work with three movement axes – X-axis, Y-axis, and Z-axis. The X-axis travels left and right, Y-axis moves forward/backward, while the Z-axis goes up/down. All the axes are driven by a servo motor and precision guide rails for high machining accuracy.As a friend said, “3-axis machines are perfect for machining slabs of parts.” Five of their six 3-axis machines take two to three minutes per part and the other a little longer… still faster than what they could do manually. Such machines are often rated 10-15 kW, meaning they can easily cut through thin metal sheets. It is a little small, but for most mechanical processing work, that 0.01mm of machining precision would be enough.
Normally it is used in mold, part machining, and small-volume production. There was an article I read about how a manufacturing company managed to increase its production efficiency by 30% after implementing the most up-to-date versions of 3-axis CNC machines. Operating at blistering speeds, these machines cut metal into any shape within 1000 mm per minute. These machines can be purchased for anywhere between $50,000 and $100K (USD) depending on configuration & brand.It is common to hear the phrase: “To do a good job, one must first have their tools ready sharpened,” this means a lot for 3-axis CNC machines. This machine is small enough to fit into a factory and generally measures 2m x 3m x 3m, but this time on top of a table. If maintained, they typically last for ten years or more.
A friend of mine in the machining industry always tells me, “3-axis machines are like that old friend; they may not be as sexy, but you know what you’re going to get.” These do generally well, launched with 80-90 percent efficiency and hence run efficiently a majority of the time. 3-axis machines are used to reduce labor costs and avoid human errors when compared with manual operation.These machines are relatively easy for non-machine tenders to operate, which makes it easier to be able to train new employees. Just a fundamental knowledge of programming and the mechanical basics are enough to begin with. With fewer axis operations, the programming is simple. The vast majority of 3-axis machines are using state-of-the-art CNC systems from Fanuc, Siemens, or Heidenhain which offer high-end programming capabilities and user-friendly interfaces.
Another crucial characteristic is the utilization of 3-axis machines that afford more adaptability. Designed as 2D milling devices, they are easily adapted to perform basic 3-D machining. This is why small and medium-sized businesses love 3-axis machines, as they can do just so much on them without the need for going all out with sophisticated units.The most efficient 3-axis CNC machines achieved real-life usefulness, still requested modest prices, and they are reliable. Most daily production needs just don’t require 4/5-axis. Machining provided by them is of high-class quality and at the same time, it also offers savings in cost, which let these machines be retained on being preferred for machining operations.
3-axis machines are also easier to maintain, which is a good thing. Guide rail and other lubricating on a regular basis, tool replacement, system calibration to guarantee long-term stable operation. This ease of maintenance is one reason many factories select 3-axis machines as they are not only cheaper to buy but also incur lower maintenance costs.3-axis machines are used in many fields, including aerospace and automotive as well as medical equipment manufacturing. For instance, 3-axis machines can be employed in automotive manufacturing to machine engine parts and body components, while it is widely used within the aerospace sector for machining complex aluminum and titanium alloy parts
Characteristics of 4-Axis CNC Machines
4-Axis CNC machines, a vast topic. The new 4-axis CNC machines have an additional axis which is rotational and commonly referred to as the A Axis with respect to X, Y & Z. The A-axis spins around the X-Axis and is mostly 360 degrees rotating, which gives greater machining flexibility for more complicated components.I remember speaking to a friend that works in the aerospace industry who told me his company uses 4-axis machines for things like aircraft components and can machine those parts individually without needing multiple setups/streamlining. These tend to be more powerful machines, 15 kW ~ 20 kW compared with a standard accumulator of around 3-axis use additional power for driving the extra rotational axes.
Datawise, 4-axis machines do indeed maintain an accuracy while machining of about 0.005 mm, which compares favorably to 3-axis machines. This greater accuracy is important in industries where precise machining of components is required, such as aerospace and medical equipment. One renowned medical device company reported that they were able to increase product qualification rates by 15% after implementing four-axis machines.In cutting speed, 4-axis performs the best where it can be operated up to 1500 mm/minute which is almost half more than that of 3-axis. But this greater capability also makes it more expensive, with 4-axis machines starting in the $100K to $200K range. You really do get what you pay for, as those additional machining capabilities and razor-sharp accuracy are well worth the money.
After that experience and you wonder if 4-axis machines are worth it, the answer is an unequivocal yes, particularly for machining more complex parts. 4-axis machines also allow for single-setup machining of some engine components that need complex shapes such as in the automotive sector saving 20% production time.4-axis machines are bigger than 3-axis ones, which have a size of approximately 3m x 4m x 4m (more or less around +20 % compared to regular working space dimensions). Considering the latter’s capabilities, a large increase in size is understandable. 4-axis machines have a shelf-life of over 15 years with regular maintenance, which makes them economical despite the initial outlay. The yearly maintenance cost comes around 5% of the equipment cost.
4-axis machines can reach up to 90% efficiency by minimizing the time it takes to reposition an element, thus making machining a more continuous path. I read an article about one of the most successful mechanical manufacturing companies, which managed to cut its production cycle by 30% and save around half a million dollars each year with the help of such 4-axis machines.There is a higher level of skill needed to run 4-axis machines as it requires the operator to have an understanding of multi-axis programming and optimization. Modern CNC systems such as Siemens and Fanuc have intuitive programming interfaces, with comprehensive capabilities that enable operators to easily complete jobs. Operators can learn to effectively manage tire shredders using approximately 40 hours of operator-specific training.
Another advantage of 4-axis machines is flexibility, especially when it comes to irregular and complex curve machining. This makes them very well-liked in sectors such as aerospace, car, and medical equipment. For example, a 4-axis machine can be used for precise production of landing gear components by an aerospace company to ensure flight safety and performance.This class of machine requires high maintenance costs but the benefits of usability and precision far outweigh this disadvantage. All these supports are so that the components work in a stable manner for a long time, and regular maintenance lubrication calibration replacement of wear parts. The annual maintenance cost is typically $20k to $50k, determined by the use frequency and real factory conditions.
Differences Between 3-Axis and 4-Axis CNC Machines
There are a lot of little nuances in talking about the technical differences between 3-axis vs. 4-axis CNC machines. X and Y share the same 2D plane of movement while Z controls height up or down, so a simple way to think about it is that XY are all left-right forward-backward movements whereas now in your brain you can clearly see X&Y being linear on an( x, y ) axis controlling a simple two-dimensional plane shape whereas with Z (Height) filling out that silly-looking…rectangle XYZ.Shape. Three axes may be enough for machining generic shapes but what if geometry requires multiple angles? 4-axis machines follow their footsteps, except that these come with an A-axis which rotates around the X – such a machine is super useful in machining complex 3D shapes and helical surfaces.
I toured their factory and saw a new 4-axis machine of theirs. The factory manager said gleamingly, “It increased our production efficiency by 25% in a month and we are using it as a 4-axis machine”. This was mainly thanks to the A-axis, which enabled multi-face machining in a single setup vs. repeatedly repositioning upon each step. In the case of 3-axis machines, you can machine workpieces weighing about 200-300 kg (on standard versions), with a step towards those at best in type that go to even bigger dimensions – for example measuring over two meters or having diameters larger than one meter.
In general, 3-axis machines will have accuracy in the range of +/-0.01 mm making them suitable for most standard machining tasks. By comparison, 4-axis machines can achieve an accuracy of 0.005 mm and are vital for applications requiring high-precision part manufacturing. One luxury watchmaker improved their part yield from 90% to 98% by using precision milling on a high-performance, rigid machine with four axes.Price Difference: Price-wise, there is a stark difference in these two machines. 3-axis machines cost roughly between $50,000 to $100,000 for a high-quality machine whereas 4-axis are in the range of around $100k-$200K. While the greater investment upfront might deter some, as 4-axis is also more efficient and a great deal for added precision to your products, this can be offset within two to three years making it worthwhile for many companies.
Another key factor is speed. 3-axis ones can cut at 800-1000 mm per minute, and compared with them 4-axis machines achieve up to a fantastic speed of cutting ~1200-1500 mm per minute that is quite serious time for mass production. 4-axis machines: an automotive parts manufacturer used these and saved nearly $300,000 per year.The operational complexity differs between these two. 3-axis machines are quite simple and require basic CNC programming knowledge. 4-axis machines, on the other hand, are a bit more complex to operate; any operator who is in charge of operating one will have to write and optimize multi-axis linkage programs. Before that, a new beginner needs 60 hours of training to control the machine himself on 4 axes. The trouble is, a 4-axis machine can be complex to learn but once mastered take the cake when it comes to performance.
4-axis machines are utilized by one medical device company to manufacture complex artificial joint components. The parts have intricate curves that are processed properly only on 3-axis machines, which result in higher precision and improved product quality as well as less production time.4th is practical in my opinion, 3-axis has a cutting depth limit of about 50mm and our long route machines with four axes can reach over 100mm(in the bed), it’s really necessary when machining bunches/stacked workpieces. And because multi-axis machining spreads cutting forces across multiple surfaces, rather than one surface at a time as in 3-Axis machines, tools on 4-axis machines tend to last about 20% longer.
When it comes to the programming, 3-axis machines are all about spatial positioning and movement in three dimensions whereas 4-axis machines mean you must think of angles of rotation & multi-axis linkage. This makes 4-axis machines more difficult to program for, but also much less restrictive. For instance, 4-axis machines can rapidly change tool angles – by the rotational axis – when engraving intricate surfaces (which would have otherwise required multiple repositionings).4-axis machines also use more energy, at about 15% over a comparable 3-axis due to the extra rotational axis but still require less than half of that used by many horizontal systems. But the energy costs are overshadowed by increased efficiency and precision of machining. 4-axis machines typically consume 20 kWh on average and the corresponding value is around 17 kWh for a basic 3-axis machine.
Manufacturing machinery can be expensive to repair and maintain, so many factories consider cost-efficiency when choosing a new robot. Compared to 3-axis machines, the maintenance costs of a 4-axis machine are even more than that. It runs approximately around 5% annually which includes about 5% from “original equipment value” or EOQ for short. But the ultimate efficiency and accuracy provided by 4-axis machines are such a cost-effective lift that it still outweighs any upkeep costs.3-Axis vs 4-Axis CNC Machines: The 3-axis machine is a good choice for general 2D and simple 3D parts, less expensive (as compared to a combination of additional axes), you operate generally at the bar located on top of the device. On the other hand, 4-axis machines exhibit excellent performance at high-precision machining with complex shapes. While their upfront costs are higher, the long-term efficiency and precision that they provide eventually offer significant economic gains. So, if you are planning to replace your equipment with new ones then look out for the features of 3-axis and 4-axis machines thoroughly according to future production needs.
