CNC Machining Cost: Cost-Saving Factors and Tips
The advent of new innovations has brought technologies like 3D printing, but the significance of CNC machining holds its position. It is one of the most considerable choices for manufacturing components that are precise, versatile, and high quality.
However, the CNC machining cost is always a factor to consider when choosing it for your project. So, let's read the guide below and learn about it.
Factors That Affect CNC Machining Cost
CNC machining cost is impacted by various factors, and some of these are discussed in the section below.
Equipment and Machinery
The cost of a CNC machine is the first investment to make when you opt for CNC machining. It is a crucial consideration because if you do not have a machine, how would you manufacture components?
Moreover, there are various types of CNC machines, and each machine has different features, making it unique in its own way. Based on the capability of the machine, the cost will vary and impact the CNC machining process.
Set-up Costs
Set-up costs are such costs that are a part of the setup process. The creation of the design requires investing in the software and also then the cost of hiring the expert to design. The overall cost of set-up forms to be a part of the CNC machining.
Materials Selection
Material cost is also an integral part of CNC machined component cost. Materials that are high-performing, like stainless steel and titanium, offer high durability and strength and are expensive compared to other soft materials.
Moreover, the harder materials also increase the tool wear, which increases the cost of replacement and maintenance.
The cost of materials also fluctuates based on the market price. It is also based on availability, as the prices may vary, impacting the cost of CNC machining.
Design and Geometry
The cost of CNC machining increases with the increasing complexity of design. The components that are highly complex have a high cost of production as they need more time and different tools.
Components that have deep cavities, contours, and internal corners increase the cost of CNC machining.
Production Volume
Production volume is an important factor that impacts the cost of the final product, when the volume is high, the cost per product decreases.
Machine Operating Time
The time required for machining plays an important role in calculating the cost of machining. The more time machining will take the higher will be the cost of production.
Labor Costs
CNC machining is an automated process hence, there is no need for a lot of manual work. However, the cost of labor is still there, the designer who will design the CAD model will charge based on the part complexity.
Moreover, if the assembling and finishing process needs the use of manual laborers, then the cost of that labor will add to the cost of CNC machining.
Additional Costs
Apart from the major costs discussed above, some additional costs are also incurred. The costs of purchasing and repairing cutting tools.
Some components may require additional finishing, so the process for surface finishing forms is a part of the CNC machining cost.
Components are inspected for quality and then packed and shipped. The cost of inspection, shipping, and packaging are all added to the cost of CNC machined parts.
12 Tips for Reducing CNC Machining Costs
CNC machining costs can be reduced if you follow some practices. The section below features 12 important tips that can help you save on CNC machining costs.
1. Material Selection
Select materials that offer excellent functionality and affordability. By minimizing waste and making the best use of machining efficiency, you can save a lot on the cost of materials.
The table below features, in detail, the different materials and the expenses they can add to. It also shows how you can save on material costs.
Metals
| Material | Description | Cost | Cost Saving Tips |
| Aluminum | Offers high machinability | Low cost | Opting for grades 7075 and 6061 helps reduce waste |
| Stainless Steel | Corrosion resistant | Highly expensive | Go for 303 grade to save on cost if corrosion resistance is not a requirement. |
| Steel | Weldable and strong | Expensive | Opting for low-carbon steel is easy to cut and saves costs. |
| Copper | Highly conductive, thermally, and electrically | Moderate | C110 offers affordable machining |
| Brass | Low friction and high conductivity | Moderate | Free machining brass C360 is quick in machining |
| Titanium | Corrosion-resistant, high strength-to-weight ratio | Extremely expensive | Simplify design to reduce machining time. |
Plastics
| Material | Description | Cost | Cost Saving Tips |
| HDPE | High moisture and impact resistance | Low cost | Choose high-speed machining |
| PTFE | Chemical resistant | Expensive | Simplify design to save time and cots |
| Acrylic | Lightweight and transparent | Low cost | Choose cast acrylic for improved machining |
| Nylon | High resistance against wear | Moderate | Choose glass-filled nylon for improved strength and cost saving |
| ABS | Easily machinable, impact-resistant | Low cost | Go for recycled ABS |
| Delrin | Low friction, highly stiff. | Moderate | Reduce waste by using large stock |
2. Avoid Multiple Finishes
Some materials need less surface finishing because they are highly machinable, and aluminum is also present in them. Hence, choosing these materials helps save post-processing operations and costs.
So, where possible, choose them if it doesn't impact the functionality of the application to save cost.
3. Order in Bulk
When you order in bulk the raw material for workpieces, you can save a lot of material costs. Therefore, try to order in larger volumes so that you can take advantage of economies of scale.
4. Avoid Excessively Thin Walls
Unless it is very crucial for your application, try to keep the walls a little thick. Too much of the thinner walls make CNC machining expensive. However, these walls can break easily or deform.
5. Round Internal Edges with Sufficient Radius
CNC machining tools are cylindrical in shape. So, when you are machining a groove body, it will generate a rounded corner.
It is at the connection between the surface of the groove body and the vertical surface. This requires a small-sized tool, which increases the machining time and cost.
6. Avoid Deep Cavities
Deep cavities require spending a lot of time on machining, and it even increases the material waste. So, try to keep your designs with moderate cavities and not very deep ones.
7. Limit the Depth of Threads
If the depth of the thread is high, the time for machining will increase. It also increases the removal of material that causes waste. Therefore, try to limit the depth of the thread so that you can save on costs.
8. Avoiding Tight Tolerances
Components with together tolerances are very hard to achieve, and hence, the prices become very expensive.
So, if the tight tolerance is not critical to the design and functionality of the component, try to avoid it. It will help minimize the time needed for the machining, and hence, the cost will be reduced.
9. Use Standard Hole Sizes
Most of the components machines using CNC machining have holes. Now, if the holes are of standard sizes, you do not need any specialized tools. The standard tools will help you achieve the required size.
However, if you choose the sizes of holes that are not standard, you may need to spend on tools. So, unless necessary, opt for standard hole sizes.
10. Don’t Include Text and Symbols in Designs
Take out all the texts and symbols from the CNC machined components. This reduces the cost by cutting down the machining time. You can go to have the text and symbols using surface finishing like silk screening and painting.
11. Reduced Number of Clamps
Try to keep the clamping parts minimum. When you rotate and reposition the part again and again during CNC machining, you can add to the cost.
Moreover, if your component has a complex shape, you may need customized clamping fixtures, which also adds to the cost.
12. Mass Production
Consider mass production. When you produce a small number of components, the costs are divided into those limited parts. However, when you manufacture a bulk quantity, the cost is spread across that entire batch, which helps to reduce per-part cost.
How to Calculate CNC Machining Cost?
The process of calculating CNC machining cost does not have a single formula; it varies from application to application. However, you can get an idea of how you can calculate it below.
CNC Machining Cost Calculator
Estimated Cost = (Material Cost + Setup Cost) + (Machining Time * Hourly Rate) + Finishing Cost
Conclusion
So, reading the guide above, you must have analyzed how much CNC machining costs and how you can reduce that cost with the tips suggested.
If you want to have cost-effective components designed for your application, contact DEK. We have high precision CNC machining services to reduce machining costs through bulk purchasing of raw materials, optimizing programming settings, etc., and delivering high-quality, tight-tolerance, customized precision parts according to your needs.
