CNC machines can be used to manufacture products from a variety of materials, such as metals, alloys, and plastics. The cost of manufacturing a product using CNC technology depends on many factors. This article discusses the various factors that affect the price of CNC metalworking. It will help you calculate the cost of CNC machining and give you tips on reducing costs.
CNC machine tool cost- CNC machining process
CNC machining cost vary depending on the type of machine. There are mainly two types of machines used to produce parts through CNC machining: three-axis and multi-axis. The cost of the machine also depends on various factors, such as the size and weight of the machine, speed, power, and configuration. Machining costs are calculated based on an hourly rate, with an approximate cost of about $180 per hour for a 3-axis used CNC machines and about $150 per hour for a CNC lathe. The hourly rate for CNC machining on a multi-spindle machine is relatively high, ranging from 330 to 550 pln. CNC milling machines are more expensive than other machining operations due to the more complex parts. Machining costs increase with the addition of milling axes. For example, it costs more for 5-axis machining compared to a 3-axis used cnc lathe.
Processing time in CNC
The time required to process each CNC fully machined part also plays an essential role in calculating CNC machine cost. The general rule of thumb is that the more time you spend machining, the higher the machining costs, which make up the essential changeover cost. Software such as CAM requires a 3D CAD model of the project and can estimate how long it will take to complete it. A very complex project requires more time.
Work
One of the advantages of CNC milling machine over manual machining is the reduction in the number of workers involved in production. The main labor cost is the 3D CAD model designed by experienced designers for machining, which increases with the complexity of the desired product. This cost remains the same even if more parts need to be produced to reduce the price of machining the part. Then the additional cost is the labor of operating the CNC machine, which increases with the time it takes to make the part. Labor costs increase if manual work is done to assemble, finish and machine the part. Additional labor costs are added if the finished product is shipped from the workshop to a customer elsewhere.
Complexity and shape size-complex CNC parts
As the complexity of CNC machinery parts increases, machining costs rise. More complex parts may require more process steps, different tooling, and longer production times. Part features, such as sharp inside corners, deep cavities, or thin walls, increase the cost of CNC machining. Designs with simple features are easy to manufacture and save production time. More significant parts require more raw materials and time to produce so they will cost more than smaller parts.
Material costs
Material costs are also essential for calculating the cost of CNC machining. The price of the final product made by a CNC machine depends on the type of materials you are required to use to make the product. You may be required to make parts from plastic or metal materials. Since plastic materials are cheaper and less durable, the cost of machining a plastic or aluminum material is less than stainless steel. As in CNC machines, the material is removed from solid blocks. Machinists buy materials in solid blocks and calculate the product cost per block. The most common metals in CNC machining are aluminum, stainless steel, and brass. Because of the economical price and excellent machinability of aluminum, most operators use aluminum in CNC machines. Stainless steel and brass result in higher costs due to poor machinability relative to aluminum. Titanium alloy is the most expensive of all these metals, so the cost of machining this metal will be the highest, as it may require special tools to produce parts. For plastics, the price of the bulk material is less, and the required tools also cost less and require less time to machine plastics such as Nylon, Delrin and ABS.
Surface finishing-oxidized parts
For some products, surface treatment is required, which also increases the price of the final product. A good surface treatment, such as polishing, may be required to improve aesthetics and remove any scratches from the machining process. Other finishing processes may include electroplating, anodizing, painting, chrome plating, blackening, galvanizing, brushing, and water-based printing. Including any of these finishes adds an additional cost to the final product price.
Mold cost
In some production cases, standard tooling is not useful, and custom tooling is required, which also adds to the cost of production using CNC machines.
Tolerance
Costs also increase when manufacturing products with tight tolerances, as complex machinery is required to produce parts with tight tolerances. Sometimes it may be necessary to produce holes or recesses with tight tolerances, which can cause burrs on the surface, and it will take more time to reduce them.
Quantity
The size of the order has a significant impact on the cost of the final product. The total cost increases when more finished parts are required, but the cost per part decreases.
How to save on CNC machining costs
Before starting a project, calculate the cost of your CNC machine. Minimize costs when producing parts using CNC machining processes. Customers have some fixed requirements that cannot be changed, but various ways still exist to reduce processing costs.
Quantity- small batches of CNC parts
If you need to produce parts in large quantities, you can save a lot of processing costs. The cost per part will be reduced because you must design the same part only once. In this case, you must repeat the machine setup for each part, reducing production costs.
Choose materials wisely
In order to reduce the cost of the product, special attention should be paid to the selection of materials. Materials with good mechanical properties will have lower processing costs. With the product’s functionality in mind, choose the best materials available to ensure the convenience of use. There is a difference in price between plastic and metal. Of course, you can use your design needs as a guide and ask the manufacturer for more advice on material selection.
Design optimization
If some product features do not affect function, the design should be optimized to avoid processing these features, thus reducing production costs.
- Consider aperture and profile – precision CNC parts.
When manufacturing CNC parts, make sure that part features (for example, holes, contours, slots, threads, etc.) can be produced using common standard tools. Custom-sized holes and threads will require costly special tools. Many references to standard sizes used in the machining industry can be found on the Internet.
- The part design avoids thin walls and deep cavities.
Thin-walled parts and deep cavities are difficult to machine and often prone to dimensional errors. These part features often cause part vibration and sometimes lead to part scrap.
- If possible, avoid requiring very tight tolerances.
Parts with tight tolerances are more difficult to obtain and, therefore, more expensive. Control dimensions only when the overall functionality of the part requires it. One piece of advice is to design parts so that they have a common reference point or datum. This will help both you and the mechanic. First, you minimize the dimensional inspections that need to be done on the part, and second, the mechanic reduces inspection time, which reduces costs.
- If complexity is unavoidable, replace a part of that complexity with a modular component.
When a part becomes too complex, it makes sense to divide the whole part into components for assembly. This will make handling more accessible and simpler. This greatly reduces setup time, shortens machining operations and optimizes machining time. Designers commonly use this strategy to increase part manufacturability and reduce production costs. In CNC machining projects use the best CNC equipment. CNC lathe machine must have the best professional machinist. CNC lathes in our company are significantly cheaper than classic machines.