One of the biggest advantages of CNC machining for many industries is the possibility to decrease the unit cost – especially in comparison to the traditional milling or turning elements. On that note: each type of manufacturing can be optimized – parts can be produced faster, cheaper, and out of better-suited materials, often not used in that application before.
Just like in other industries, cost optimization of CNC machining is possible and can deliver many profits for clients and the machining plant.
What affects the cost of CNC machining from the client's perspective?
Mentioned low unit cost – possibly thanks to the utilization of CNC machining – is one of the main reasons for that technology's popularity.
The less-known fact behind that is related to the important threshold of such machining profitability – the minimum quantity of a batch of parts.
At RADMOT, the best ratio of quality and service level to price for the customer is achieved with production from 100 units / batch and 1,000 units / year
To put that into perspective, these are the key factors that have a direct impact on the final cost of CNC machining:
1. Lead time
Launching a CNC machining production requires time – in some situations: a lot of time. Preparation of CAD files (from technical drawings or vector files) and their translation to the G-code can be time-consuming. These files contain 'processing steps' for the machining and their preparation can take a lot of operator time and requires precision and experience of operators. That step alone can impact the whole manufacturing process and sometimes make it cost ineffective (eg. for small batches of parts that could be machined with automatic mills or lathes). That labor cost is an important part of every CNC machining quotation,
Before the CNC machining begins, operators often go through the prototyping process – which allows them to check parameters like the part design, selected cutting tools, surface quality, dimensions, and correctness of the prepared program. That step is also a part of the quotation – just like the previous can be significant in the whole cost estimation,
3. Number of parts in a batch
Machining time of a particular CNC device is often estimated with a flat fee, which is why the bigger amount of parts ordered in one batch, the lower the unit cost might be. The main reason behind that is simple – cost breakdown. For example, in 100 parts batch preparation cost can be even close to 50% of the unit cost; with increasing amounts, such flat cost breaks down more efficiently.
On the other hand – CNC technology allows fast relaunching of already finalized projects, especially in the factory that already produced the previous batch.
In these situations, the main cost of the manufacturing process will be the machining time – mainly due to the availability of tested CAM files and parts known to the operators.
To even better understand the complexity of quotations for the CNC machining processes it is worth mentioning factors that can influence the cost of particular orders:
- time required to prepare the production of CNC machined parts – that includes the time of the operators and cost of the software (CAD, CAM, etc.),
- machine and special tools cost – that includes maintenance and regular calibration of devices,
- cost of the raw materials that are used in the manufacturing processes – is often included in the quotation and delivered by the machining shop. The main reason for that is logistics and quality control – professional CNC machining companies have tools and experience to check material (eg. repetitive quality of alloy blocks used to machine parts),
- finally – a big element of the parts manufacturing cost is machine time – which includes consumed electricity but also things that are related to the whole company infrastructure (buildings, etc.).
Things mentioned above – combined – create a cost of the CNC manufacturing process, that is also dependent on the type of machining device (traditional or 5-axis mills, laser cutters, lathes, etc.), selected material, and the ordered unit amount.
On that note – we can move to answer an even more important question: 'how to save on CNC machining' or 'in what areas it is worth seeking more cost-effective solutions for CNC'.
👉🏻 What is important: professional operators from RADMOT can help you to find these savings. Ask us for a free quotation and if you need – support in finding the most cost-efficient solutions.
Where and how to seek savings in the CNC machining processes?
As mentioned above, a big part of the CNC manufacturing process is the preparation of the whole process. Re-launching – especially in the same factory – can be a source of significant savings, mainly due to the availability of tried and tested CAM files.
On top of that – there are a few methods that can help to reduce the cost of CNC production by lowering the machine time required to finish the production of part:
1. Selection of the right material
Very often 'good enough' alloy or 'practically identical for that application' material can be a perfect replacement for 'a perfect for that part'. Many parts can be successfully machined out of polymers (not alloys) – just that change can reduce the cost of production significantly, without compromising the final quality of the product. Of course: such a decision should be made in cooperation with the client and professional CNC operators, with in-depth knowledge of material sciences,
2. Project simplification
Rounded edges, perfect surface finish, thin walls, or holes sized too deep can result in increasing machining costs. On the other hand – proper execution of complicated shapes with CNC mills can be costly. Such shapes require changing work parameters and more machining time,
3. Where it is safe for the project
Leaving tight tolerances. It is another practical solution that can save machining time,
4. Selection of the right technology to remove material
Not every part should be machined on a 5-, 7-, or 11-axis CNC mill. In many applications, more 'cost effective' 3-axis will be just as good, but significantly cheaper solution,
5. Continuous cooperation with one CNC machining factory
As mentioned, relaunching an already executed project is much more cost-effective. For that application (eg. production of another batch of identical parts) the main cost of manufacturing parts will be machining time and material – not the preparation of the whole process,
6. Good planning
'Cito' CNC machining orders are often very costly. An order scheduled in advance can result in faster and more efficient machining (also: cost-wise),
7. Good preparation of order
Translation of the CAD file to G-Code can be time-consuming, but the preparation of additional CAD files for the (hand) technical drawing can take even more. It is an often overlooked way to decrease CNC machining costs, but it is worth remembering.
👉 But remember: decreasing the cost of CNC manufacturing does not have to impact the quality of manufactured parts.
On the other hand – there is no 'golden method' for such cost optimization.
Professional CNC Company – like RADMOT – approach each order and quotation individually, with a strong emphasis on supporting clients at every step with knowledge and experience.
Such cooperation results in combining better quality and often – lower cost of the whole manufacturing process.
Best or right materials?
On top of that – the final cost of parts manufacturing is strongly related to the selection of the right materials.
Finding a cheaper substitute – with similar mechanical parameters and applications – is possible.
💡 A tip to think about
A good example of that approach is small gears – for years were machined from alloys (steel, aluminum, etc.), but in many applications (eg. automotive) are replaced successfully with polymers.
Their advantages are visible at first glance: low mass (do not require very costly skeletonization to decrease weight), good enough mechanical parameters, and lower material cost.
The other example is plexiglass as an alternative to polycarbonates – in most applications, the first one is good enough and also: much cheaper.
Another way to find a cheaper material is selection based on the potential of additional surface bettering processes (eg. aluminum anodization).
The cost of cheaper alloys, subjected to such processes, can be (combined) lower than 'the best type of alloy'.
On top of that – the right material selection can also impact the required manufacturing time.
More machinable materials can decrease that cost significantly.
Such small tweaks – even between series or types of alloy can lead to significant savings in the CNC machining process.
Regardless – the final decision to change the material mentioned in the technical specification should be discussed and made in cooperation between the client and the machining factory team.
We will price your order and suggest solutions to find savings
At RADMOT, we can offer CNC milling services, CNC turning services as well as many additional services, including washing, aluminum anodizing, laser marking and assembly.
Contact us and tell us what you need. We have been providing CNC services for almost 40 years. Our quote is completely free. And if you have any doubts about what technology will work best for you, our expertise is at your service.