FACTORS INVOLVED IN CNC MACHINING PRICE & KEY TIPS TO REDUCE IT
The widespread implementation of CNC machining results from its low-cost production capabilities. Moreover, some other aspects are also a part of this adoption. Additionally, it is helpful to know that each CNC machine has a lot of flexibility. And it makes it beneficial in all situations.
Yet, calculating the CNC machining price is not so simple. As multiplying or adding up the individual costs. It is a matter of many factors that need to analyze numbers to arrive at an accurate estimation. Let’s take a look at the various factors that influence it. Later, I will talk about essential tips to reduce the CNC machining costs.
Significant factors that affect CNC machining price and cost:
The following are the factors that affect CNC machining costs;
1. Type of material:
There is a direct relation available between the;
- The type of material that we are using for manufacturing CNC machined parts
- And the price of CNC machining
The price of the material completely depends upon the raw material. And we use the raw material to the machine to produce the final product. For instance, working with wood be cheaper than working with stainless steel. The main reason is that SS (stainless steel) is more expensive than wood.
Furthermore, the properties of the material also influence the CNC machining price. For example, we need special tooling items to machine titanium material. While standard tools can work on metals such as aluminium or wood. Thus, we control the cost of raw materials and machining costs by the nature of the machined material.
2. Cost of labour:
Another critical factor in calculating the cost of CNC machining is labour cost. We know that CNC machines can operate in very efficient way. But it needs individuals to program the CAD / CAM files that control the CNC machines. There will be the need of expertise of a machinist or engineer. To configure the CNC machine before starts its working. In many conditions, you may need both for the configuration of CNC machines.
You need a quality control specialist to follow QA / QC standards. And so, the CNC machining price will include some of the labour costs. It is pertinent to mention here that labour cost will be higher. This is because you will get the services of skilled staff. As compared to their inexpert counterparts.
The compensation will be proportional to level of skill to simplify machining process. Considering all this, we cannot ignore the cost of labour.
3. CNC machined parts quantity:
Production volume also plays a vital role in determining the CNC machining cost. You can conclude that the larger the number of CNC machined parts, the higher the total cost. While this fact is correct, we need to keep one more thing in mind during the cost calculation. That mass production reduces the cost per unit in CNC machining. Especially when it involves a single CNC machining process on many components.
Thus, the CNC machining cost of 20,000 parts per unit will be cheaper than the machining cost of 20 similar parts. For easy understanding, larger production volumes can attract higher machining costs. But when it comes to the cost of production per unit, it will spread out.
4. Design of the part and geometry:
The design and geometry of the machined part determine its characteristics and usability. I mentioned that wherever there will be a partial complication in the component;
- There will be an increase in program time
- Setup time
- Run time will be longer than standard
Thus, the CNC machining cost of complex components will be higher. At the same time, they may need special tools (e.g. such as laser cutting) in various setups. And it also increases the likelihood of a further increase in production costs.
So, we can say that the larger components will have a higher cost of CNC machining. And the real reason is that it will involve more input feeds and take longer.
5. Tolerance and precise surface finish:
The accuracy and precision of the finished product are proportional to machining cost. These factors are very important when we have no room for error with strict tolerance.
The customer usually makes such demand for machining parts that will assemble together. And tolerances reduce interference between the components. During the machining process, tight tolerances are no easy task to achieve. For internal geometries like holes or cavities that result in burrs.
As a result, these components need physical or manual inspection. And that includes other processes, such as finishing or surface treatment. These different processes also increase the CNC machining price.
Essential tips to reduce the CNC machining price:
To help with cost reduction in CNC machining, you can make changes in;
- Machining time
- Start-up costs
- Materials costs and more
There are specific product requirements that you cannot change. But taking steps to improve your design can reduce CNC machining costs. Here are some steps that are helpful to reduce CNC machining price;
1. Rounded internal corners in CNC machining:
Machines need to stop for sharp, 90-degree angles; the part rotated. And then, the CNC machining process continues. These extra steps take extra CNC machining time, and they often cost you extra money. Changing the design of the inner corner of a component can reduce CNC machining costs.
If you change the design to incorporate rounded corners, the machine can run to produce the part. And as a result, you are likely to diminish your bottom line. Take it one step extra and make sure that the radius of internal corners is at least 1/3 depth of the cavity. Larger tools can cut larger radii at the corners in efficient way. Yet, a small tool with a smaller radius completes the process in many times.
2. Do not make deep pockets:
Let me tell you that deep pockets harm the CNC machining price. As CNC machines need to remove a lot of material to make deep pockets. This material removal process takes a lot of time and requires special tooling.
So when designing pockets, keep their depth low; but keep assembly work in mind. The process will take very little time, and the CNC machine will not have to work much. With less time, the tool’s usage will also be less, reducing the machining cost.
3. Tight tolerances and CNC machining cost:
When it comes to making a part with tight tolerances, the machining cost will be very high. One of the reasons is that it involves a lot of CNC machining time. The second reason is that the part with tight tolerances requires manual inspection. And both of these factors increase the machining cost when creating a complex part.
Some parts need tight tolerances for assembly and fitting. But programmers should avoid creating complex designs wherever possible. Even, it is best to avoid specifying a range of specific tolerances. Because where tight tolerances are available, it takes more machining time to work.
This will save machining time and make bench workers not have to work hard while deburring. At the same time, there will be no extra need for manual inspection too.
4. Thin walls and CNC machining:
When the workpiece has thin walls, it will take more CNC machining time. To manufacture these components, the operator runs the program with low speed. Along with this, there will also be a need for special tooling to make thin walls.
So, the designer should give preference to thick walls instead of thin walls. The thick walls are easy to manufacture on the CNC machine. So the CNC machine will complete the program in quick way. And because of this, there will be a reduction in the CNC machining price.
5. Avoid small features:
Parts with a lot of small features take a lot of CNC machining time. The programmer has to work very hard to generate a program for these small features. Moreover, this will also take a lot of setting time for the CNC operator. So if there is not a specific need, do not design parts with small features. It will reduce a lot of machining costs.
I am hopeful that I mentioned all essential details about CNC machining price. First, I focused on the factors involved in CNC machining costs. For cost calculation, you have to know about the type of material and labour costs. The quantity of machined parts and surface finish are also involved in cost-calculation.
Later, an explanation provided about key tips to reduce the CNC machining costs. Details about some tips explained above. Yet, I will cover some more tips and tricks in upcoming posts. Such as larger quantities, avoiding many finishes, and optimized tapped holes.
Link 1: stainless steel
Link 2: CNC operator