Introduction to CNC Machines and Their Costs(cast steel vs cast iron Coral)
- source:DAHLER CNC Machining
Deciding whether to purchase a CNC machine and determining the cost is an important consideration for many small businesses, machine shops and manufacturers. This article will provide an overview of CNC machines, their key components, the main types of CNC machines and their typical costs. It will also discuss factors that affect CNC pricing.
What is a CNC Machine?
A CNC machine consists of three main components:
- The machine frame and workholding device that sits on the machine table where the raw material is mounted. This can include vises, clamps and fixtures to hold the material stable.
- The tool holder or head where the cutting tools are mounted. Common toolheads include milling machines, lathes, laser cutters, waterjet cutters and plasma cutters.
- The controller which is the computer and software that drives the machine tool. CAD/CAM software converts the design into commands for the CNC machine to move the toolhead and cut the material precisely.
CNC machines follow these programmed instructions to shape metal, plastic, wood or composite materials into finished parts. They perform repetitive, precise machining tasks much faster than manual machining, expanding the complexity and sophistication of parts that can be manufactured.
Types of CNC Machines
There are several basic types of CNC machines used in manufacturing:
- CNC Mills - A CNC milling machine has a cutter attached to the toolhead that rotates at high speeds to remove material. Common milling operations include face milling, end milling, slot milling and pocket milling. CNC mills are very versatile and can create prototype parts from metal, plastics and other materials.
- CNC Lathes - On a CNC lathe, the workpiece rotates at high speed while the cutter tools shape the material. CNC lathes are used for machining cylindrical parts, discs, tubes and other workpieces that require rotational operation. Common lathe operations include facing, turning, boring, threading and more.
- CNC Routers - Controlled by CNC, these routers have an interchangeable rotary cutter that machines wood, aluminum, steel, plastics and composites into the desired 2D or 3D shapes. They are important tools for signmaking, woodworking, and prototyping.
- CNC Lasers - CO2 or fiber lasers can effectively cut, weld, etch, and mark most materials with high precision. CNC laser cutters have head positioning controlled by computers and are used in cutting industrial patterns and small prototypes.
- CNC Plasma Cutters - Similar to laser cutters, CNC plasma cutters direct a plasma arc through an aperture to melt and cut electrically conductive materials like steel, aluminum and copper. The intensity of the plasma jet can be computer controlled for precision cuts.
- CNC Waterjets - Using an extremely high pressure jet of water mixed with abrasive, CNC waterjet machines can precisely cut softer materials like rubber, plastics, wood, and composites without heat damage. The stream of water follows the toolpath generated by the CNC machine.
Cost Considerations for CNC Machines
The costs for CNC machines can range dramatically from under $10,000 for very basic machines to over $100,000 for large, complex 5-axis machines outfitted with the latest technology. The exact cost depends on these key factors:
- Machine Size - The larger the workspace, the more expensive the machine. Larger machines are needed to produce bigger parts. Desktop CNC mills and routers are the most affordable machines.
- Number of Axes - Entry-level CNC machines operate on just 3 axes (X, Y and Z linear motion) while more advanced 5-axis machines also add tilt and rotation. More axes increase flexibility and allow complex parts to be machined in one setup.
- Control System - Simple CNC machines use standard g-code controllers while high-end machines have advanced software and touchscreen controls that are more expensive.
- Precision and Accuracy - Machines with ballscrews, servo motors and tighter tolerances will produce more precise parts but also cost more.
- Materials Machined - Machines made to cut harder materials like stainless steel or titanium will be more durable and hence more costly.
- Brand Reputation - Well-known CNC companies like Haas and Hurco that specialize in machining will be priced higher than generic machines.
- Automation Features - Options like automatic tool changers, pallet changers and robotic part load/unload systems increase costs but also productivity.
- Purchase Options - Buying used CNC machines saves substantially over new equipment. Financing options like leasing also impacts monthly costs.
Keeping these factors in mind will help determine the right CNC machine with the appropriate capabilities at a reasonable price.
Cost Ranges for CNC Machine Types
Here is an overview of the typical cost ranges for the most common CNC machines:
- Small Benchtop CNC Mills - $5,000 - $20,000
- Full-Size 3-Axis CNC Mills - $50,000 - $100,000
- 5-axis CNC Mills - $80,000 - $150,000
- Mini CNC Lathes - Under $10,000
- Single Spindle CNC Lathes - $25,000 - $60,000
- Multi-Spindle CNC Lathes - $60,000 - $120,000
CNC Plasma Cutters
- Tabletop CNC Plasma Cutter - $15,000 - $50,000
- Large Format Plasma Cutters - $50,000 - $200,000
- Desktop CNC Router - $3,000 - $8,000
- Industrial CNC Routers - $25,000 - $50,000
- 5-Axis CNC Routers - $50,000 - $100,000
CNC Laser Cutters
- Small Format CO2 Laser Cutter - $10,000 - $20,000
- Large Format Fiber Laser Cutter - $50,000 - $150,000
These prices illustrate the wide range that CNC machines are available at depending on their capabilities, work envelope and production volumes they are designed for. Even affordable desktop CNC mills and routers can give smaller businesses and shops access to automated fabrication. On the other end, 5-axis CNC mills used for machining complex aerospace and medical parts can be over $500,000.
Evaluating Total Costs
When evaluating the total costs for purchasing CNC equipment, machine buyers should account for:
- Purchase Price - The upfront price to acquire the machine, which can be reduced through used equipment or financing.
- Setup Costs - Expenses for delivery, installation, workspace preparation, electrician fees and initial tooling.
- Operating Costs - Ongoing costs for cutting tools, repairs, maintenance, spare parts and consumables.
- Training Costs - Investing in operator training and CNC programming education.
- Workholding & Fixtures - These aid in properly holding parts on the CNC machines when machining.
- Software Costs - Creating or purchasing CAM software to generate toolpaths and g-code.
While the machine purchase price is the most obvious cost, buyers should plan for about 30% on top of that for additional setup, training and operational costs. Planning ahead for these secondary costs can prevent unexpected surprises down the road.
In conclusion, while advanced CNC machines represent major capital equipment investments, even compact CNC desktop mills and routers are cost effective ways for smaller manufacturers to reap the benefits of automation. Carefully considering the type of CNC machine, required features, operating costs and additional investments in tooling, software and training will help find the most return on investment. CNC machines make manufacturing more efficient, consistent and cost effective. CNC Milling CNC Machining