CNC machine shop can be considered the new normal of the manufacturing industry. Since the beginning of the industrial revolution, factories across the manufacturing industry have been in constant evolution, letting us see factories moving from a great number of people working on a long production line to an automatized series of machines working in synchrony for higher efficiency.
However, perhaps the most recent evolution has been changing those long production lines or big manufacturing shops full of machines to what is known as a CNC machine shop. But what is that?
What is a CNC machine shop?
A CNC machine shop is usually a small but specialized manufacturing facility which is dedicated to cover their clients’ specific needs for customized parts and prototypes to be delivered in a short period of time.
It can also be part of a bigger factory dedicated to covering those needs described. Many big manufacturers have an R&D department that works hand in hand with the CNC machine shop in order to prototype and develop new parts to improve their products or even whole new products.
While a CNC machine shop may be limited to producing small batches, it has other capabilities and characteristics that make them excel. Among the most relevant, we can highlight:
- Highly advanced technology for increased precision and geometric complexity capabilities.
- Capable of working with different metals, plastics and other special materials.
- Capable of specialize and concentrate their skills on specific industries such as aerospace or automotive industries.
- Capable of providing holistic services that cover the whole product lifecycle to transform your idea into a tangible product.
This usually includes design, prototyping, testing, and production.
Clearly, a CNC machine shop needs to be competitive and efficient to deliver in the current market. To do so, a CNC machine shop will make use of top-notch technology and highly-advanced machines, so let’s take a look at what a CNC machine shop usually looks like.
What equipments will you find in a reputable CNC machine shop?
Although each CNC machine shop will be different, and the things each of them have inside will vary based on their size and specialty, any serious CNC machine shop should have at least the equipment and machinery that will be described below.
This is the very basic of any reputable CNC machine shop. A milling machine, sometimes called multi-milling machine depending on the capabilities, is a machine that uses a cutting tool that cuts through the material in a rotatory movement. They can perform different operations, from creating flat surfaces to generating threads.
Multi-axis CNC machine
Also called machine centers, this is usually the golden egg of any CNC machine shop. This is a very advanced type of machinery, with more complex features and an extended list of capabilities. The most relevant of the features is that it can perform cutting operations on 3,4 or 5 axes, and the more advanced can even operate on 7 axes. Hence the name.
It is important to highlight that the more axes the more complex the part that can be manufactured. However, it is true that it is not the best idea when manufacturing a simple part, since multi-axis machines require longer configuration. The process usually includes creating a 3D model in a CAD/CAM software program and creating the CNC program that will be used by the machine, at the least.
Originally, a lathe is a manually operated machine. But we can now see CNC lathes, and these are the most common ones in a CNC machine shop. This type of machine tool does the opposite of a milling machine. Instead of using a rotating cutting tool, the part is the one that rotates while the tool approaches it in a linear motion. Given this aspect, CNC lathes are also called CNC turning machines, and are commonly used for sanding, knurling, and facing operations.
As the name implies, a grinding machine is used to grind the surface of the part to remove small pieces of material in order to improve the surface finish after a machining process. The tool uses a wheel usually made of particles from a hard material which are kept together by means of a binding agent. The material and type of wheel used will depend on the level of surface finish required. Of course, the higher the level the more costly it will be
This tool allows the CNC machine shop to transform the raw material into smaller pieces that can be easily machined. Usually, a CNC machine shop receives long bars and slabs that require to be cut before machining, and this is done with a bandsaw.
Taking from the name, this machine works in a similar way as a regular press. However, it is specifically used to drill holes. The main difference with a handheld driller is that the movement is more precise and controlled by a lever. Some of them can perform other operations when the tool is changed.
Micro machining tools
These are very special tools that are not found on all CNC machine shops. However, these tools help any CNC machine shop to achieve very special microscopic finishes and surface finish patterns.
Electro Discharge Machining (EDM)
EDM equipment is used in a machining process that, instead of cutting through the material, vaporizes particles from the surface using sparks from electric current. This is a preferred process for hardened pieces with the advantage that there are basically no forces applied on the part and deformation can be avoided.
Surface finishing tools
The micro machining was already mentioned as a surface finishing tool. However, there are other surface finishing processes that may require specific tools. These processes are usually applied to add or improve the properties of the finished part like smoothness, glossiness, color or to provide it a mirror-like look. To achieve it, a CNC machine shop requires at least some painting tools, but the most reputable CNC machine shops also add tools for processes such as polishing, anodizing, and sandblasting to their capabilities.
Coordinate measuring machine
Measuring and control tools are a must to guarantee high-quality results. A CNC machine shop needs to verify dimensions and tolerances as well as other properties. So, a coordinate measuring machine is very important as it allows to measure almost any geometry in a very accurate way.
As mentioned in the previous point, measuring and control tools are necessary in any CNC machine shop. And the vernier caliper is another measuring tool that you will find in any reputable CNC machine shop. This tool allows to measure inner and outer dimensions as well as depth.
Micrometers and pin gauges
For higher precision measurements micrometers work better than other measuring tools. It can also measure different dimensions like length, thickness and depth. For small holes that require inspection of diameters and its tolerances, the pin gauges are great tools.
Obviously, apart from all these machines and tools you will see the specialists working with them. Also, some areas of the shop will have raw material storage although this is sometimes stored in external warehouses. In those CNC machine shops that offer the whole product lifecycle, computers with CAD/CAM software will also be seen for the engineers and technicians to work on the designs before prototyping and production is carried out by the machinists.
Quality Control (QC) and Quality Assurance (QA) in a CNC machine shop
So far, we have made clear the fact that inspection and verification are essential for a CNC machine shop to achieve high-quality results. And this is what quality control and quality assurance are all about. Now, how does a CNC machine shop carry out QC and QA? You may wonder.
The most common actions taken by a CNC machine shop for QC and QA are as follows:
Raw material inspection
When receiving the materials that will be used for prototyping and production, the CNC machine shop will have their quality control inspector to visually verify the material is fine for use.
Inspections by machinists
Machine operators are the first ones who can identify whether the part is as expected or there are any quality issues. They can verify the quality of the part during operation or immediately after removing it from the CNC machine.
Process probing inspection
CNC machine shops generally have highly advanced machinery which allow them to use automated in-process probing to verify tolerances as part of the CNC program.
QC department inspection
This is a third step in quality inspection and assurance, which comes after the process probing and the verification made by the operator. The quality control department performs this third inspection based on the statistical process control system.
Communication with the client
Clearly, the best way to verify the quality delivered is by confirming the satisfaction of the client. And this is only possible by maintaining a clear and effective communication.
The human factor of a CNC machining shop
While the current digital world has changed the look a CNC machine shop by introducing cloud computing and interconnectivity between CAD/CAM software and the machines themselves, what has not changed is the need for trained and experienced engineers, technicians and operators.
For many, it may seem that the machines and their technologies do all the job. But nothing is further from the true. At the end, without the right input, the machines cannot achieve high-quality results.
Machines and their technological developments do make the work easier, more efficient and more accurate, but some skills are still required to make them work as desired.
Among the most important skills required in a CNC machine shop, there are:
- Problem solving skills to correct errors, find areas of improvement and take the full potential of the machines.
- Technical knowledge to understand things such as CAD/CAM software programs.
- Attention to detail and awareness to identify potential issues and avoid accidents that may result in serious injuries.
- Mathematical skills to understand complex instructions and ensure proper dimensioning and tolerances on the most complex geometries.
- Stamina to work under pressure and demanding conditions.
Safety at the CNC machine shop
Having different types of machines and tools working at the same time can become dangerous if the right measures and actions are not taken to ensure safety. Any CNC machine shop should, at least, consider the following to guarantee safety:
- Provide the employees with the appropriate apparel, including protective equipment such as goggles and safety shoes.
- Make sure operators are in the right physical and mental conditions to operate the machines. A sick or tired operator could put the entire shop in danger, not to mention one under the effects of alcohol or drugs.
- Avoid distractions and prevent machines from being unattended.
- Keeping machines in the right conditions by performing periodic maintenance and updates.
- Having clear hazards control guidelines and an emergency plan.
- Having an appropriate waste management plan.
How to choose the best CNC machine shop for you
You do not need to have your own CNC machine shop. If you are a product developer or you own a business that require some manufacturing services, you just need to find the best service provider. This means the best CNC machine shop for your specific needs. Here are some of the aspects you must consider when choosing.
Value and price
If you are going to be in the manufacturing business, you will need o ensure a long-term relationship with your provider. Moreover, it has to be valuable and prices need to be competitive so you can actually see a profit.
Make sure your ideas and designs are safe. They are yours and they represent your value. A non-disclosure agreement is always recommended.
Quality and reliability
Of course, you want to make sure you can rely on your provider to give you high-quality results. This can be supported with certifications such as ISO.
Communication and understanding
Last but not least, a good effective communication is always essential so your provider can really understand your needs and what you expect from them. If you notice it is being difficult to reach your provided, you may be better off somewhere else.