Are you thinking about using CNC milling to machine aluminum parts? It’s a popular way to shape aluminum and other materials for all sorts of products. Machines use drills and cutters to carve designs and shapes very precisely.
More and more companies are using CNC to make parts from aluminum. It’s used across many industries, like automotive, robotics, electronics, construction, aerospace, etc. The metal is lightweight like plastic but much stronger. Shaping aluminum is also faster and cheaper than steel or titanium alloy.
Before starting an CNC aluminum milling project, it’s important to have a clear idea about all the aspects. We will cover five important questions you need to know the answers to. Choosing the right aluminum CNC milling services starts with knowing exactly what you need from the machining process.
Why CNC Milling for Aluminum
Aluminum is one of the most popular materials for CNC machining projects. It is very strong but also lightweight, making it perfect for mechanical parts. It also resists corrosion since it forms a thin outer layer of oxide. This is why you see the use of tons of aluminum parts in cars, airplanes, medical equipment, and electronics.
CNC milling is especially well-suited for machining aluminum. Unlike other strong metals, it’s very easy to cut and shape with tools. Because of the good machinability, it only takes around a third of the time to CNC mill aluminum compared to steel or iron.
There are a few key reasons why aluminum mills so efficiently:
- It has a lower melting point than metals like steel, making it easier to cut without heating up.
- Aluminum is also not very hard, so end mills and drill bits can penetrate the material smoothly.
- The metal is not prone to work hardening when getting cut, like stainless steel does. It allows for continuously fast cutting without tools dulling or breaking prematurely.
CNC milling is a great machining method for aluminum due to its excellent machinability and the material’s unique physical properties.
Pros and Cons of Aluminum CNC Milling
Let’s take a look at why CNC milling is such a good match for aluminum and some disadvantages you should be aware of.
Pros of Aluminum CNC Milling
Why would anyone choose aluminum over other types of metals for CNC milling? It’s because the metal offers a number of advantages:
a. Good Strength-to-Weight Ratio
Aluminum is lightweight but highly durable, making it perfect for components that need to withstand heavy use but not add excessive weight. This property makes aluminum suitable for critical parts in industries like aerospace and automotive.
- Easy to Machine
Aluminum is easy to cut and shape with a CNC machine. It chips away cleanly and holds precision well during the machining process. You can mill complex geometries quickly without as much risk of tool damage or workpiece defects.
c. Efficient Heat Transfer
The material has high thermal conductivity, allowing it to quickly dissipate any heat generated during machining. It reduces the possibility of overheating of cutting tools or deforming of the workpiece.
d. Great Electrical Conductor
Aluminum is a better electrical conductor than stainless steel. It’s highly suitable for applications that require electrical components, such as wiring, circuit boards, and enclosures.
e. Corrosion Resistance
Aluminum alloys exhibit good corrosion resistance thanks to a protective oxide layer that forms on exposed surfaces. This makes the metal suitable for marine environments and applications involving exposure to moisture.
f. High Recyclability
Being a recyclable material is a big plus for aluminum. Excess material and scrap pieces from CNC machining can easily be recycled rather than treated as waste.
Cons of Aluminum CNC Milling
Here are some challenges to keep in mind when doing CNC milling with aluminum:
a. Less Strength
Aluminum is not as strong as other metals like steel. It can’t handle heavy loads or stresses as well, making it unsuited for components requiring high tensile or load-bearing capabilities..
b. Lower Hardness
Aluminum is a softer metal too. It won’t last as long if something is rubbing against it a lot. The surface might get scratched or worn down faster than a harder metal.
c. Aluminum Buildup
When you cut aluminum, some of it can stick to the cutting tool instead of chips. This is bad because it makes the tool less sharp, making the cutting rougher and less accurate. It also shortens the life of the expensive tool. You need to machine aluminum at higher speeds to prevent buildup from happening too much.
How Long Does it Take for Aluminum CNC Milling?
Wondering how long aluminum CNC milling takes? The time it takes can vary a lot based on different things.
A manufacturing company needs some time to make a quote after you send over your design files. Usually they can look it over and respond within a day or two. They have to take measurements from the files and figure out how long it will take to make.
Once you agree on the price, then the real work begins. So, setting up the manufacturing process involves programming the design into the machine’s controls and preparing the machine to start the production.
Depending on the size and detail, this part can range from a few hours to several days. Small items go quickly but large intricate designs take time. On average, CNC machines go about 1 foot per minute. So, how long a job takes also depends on how long the material being cut is and how deep the cuts need to go. This means that a long thin piece may be quicker than a short thick one.
When machining ends, the products aren’t quite done yet. They need finishing touches like smoothing edges and fixing the imperfections. Quality checks are run to make sure everything meets expectations. Finally, the packaging and shipping wrap up the process.
Most companies give quotes before starting a job so they can estimate the time. As a general rule, simple prototype parts usually only take 1-3 days. Small batches of less than 50 similar parts often take around 8 days.
Bigger production runs take more time. About 1,000 identical parts typically takes 3-4 weeks. And a massive order of over 10,000 parts could take 1-2 months total. Custom one-of-a-kind parts usually require 2-3 weeks due to extra back-and-forth with the designer.
How Much Does Aluminum CNC Milling Cost?
To calculate the costs of aluminum CNC milling, you need to consider several factors to determine the overall price. Let’s break down each of these components.
a. Cost of Materials
Aluminum comes in different grades that affect the price. Take the price of 6061-T6, a common aluminum alloy for CNC milling, for example.
The prices for plates (or blocks) in this alloy can vary based on the thickness and size needed. As an example,
- A 12×12-inch 6061 plate (with 0.25-inch thickness) = around $43
- A 24×12-inch plate = around $87
b. Machine-related Expenses
Running a CNC machine takes power and regular maintenance. A company will factor in costs for things like tool replacements, coolant, and lubricants into the final quote. And rates tend to be higher for more advanced machines.
c. Labor Costs
CNC operators are paid hourly wages plus benefits. Experience level affects pay, with rates usually falling between $15 to $30 per hour.
But the complexity of a part increases this cost because more intricate designs require longer setup and machining times. Specialized skills or programming can also increase labor expenses.
d. Overhead Expenses
For low volume prototype work, overhead costs may not drive the total too much higher. But things like facility costs, utilities, and administration are more significant for large production runs. ISO-certified machine shops may charge a bit more to ensure high standards.
The Final Figure Is…
For estimating aluminum CNC milling costs, it’s best to get quotes directly from machine shops. Prices can vary greatly due to unique part designs, material selections, production quantities and turnaround time needs.
As a rough guide, expect to pay between $75 to $200 per hour of CNC machine operation after accounting for material, labor, and other costs involved.
Communicating all project details upfront helps you get the most accurate pricing.
Are There Any Other Methods to Get Aluminum Parts?
Except for CNC milling, there are a few more methods to manufacture aluminum parts. Let’s take a look at them:
1. Metal Casting
Aluminum metal casting is a process of pouring molten aluminum into molds to give it particular shapes. The molds are prepared with the exact shape and details of the desired part.
Cast aluminum is lightweight but strong for its weight. Different molding methods let manufacturers make complex metal parts with close tolerances and smooth finishes. Automotive engine blocks, electronics casings, and medical devices often use aluminum casting for these properties.
2. 3D Printing
Aluminum 3D printing uses laser cutting to create metal objects using powdered aluminum. A high-powered laser melts thin layers of aluminum powder, fusing the particles together to build three-dimensional shapes one layer at a time.
The process lets engineers 3D print aluminum parts with intricate internal designs. Cars and airplanes use this method because the lightweight metal lets vehicles fly higher and go farther on less fuel.
3. Sheet Metal Fabrication
The process involves shaping aluminum sheets, including cutting, bending, and forming, into various components and products.
Fabricated aluminum is found in many everyday products due to its strength and corrosion resistance. Planes use it for wings and fuselages. Cars use it for their frames, wheels, and many engine components. It’s also used for food packaging like soda cans, foil, and freezer bags.
Conclusion
These questions discussed above will help you find the right aluminum CNC milling services for your project. Remember, getting quotes from different machining shops is key to finding the best fit for your needs in terms of price, turnaround time, and quality products. There are other ways to create aluminum parts, but CNC milling offers a balance of precision, speed, and cost-effectiveness for a wide range of applications.
For aluminum components done right, check out Zintilon’s CNC milling services. As experienced aluminum fabricators, we have the answers to your production challenges and can deliver high quality parts on schedule and on budget. Contact us to discuss your project.
