Most people thinks that machining metals such as Aluminum should involve the usage of high-end milling machines that can carry out extremely complicated work. There is no denial that spindles of these machines can spin their cutting tools at a speed comparable to the best drills. However, the CNC router provides spindles that can operate and rotate at a higher speed than the regular mill.
Is It Possible to Cut an Aluminum Material with a CNC Router?
Machining materials such as Aluminum with a CNC router is possible with most of the CNC types. The material can be easily cut by matching the right feed rate and end mill bit with its properties. It is essential to consider that cutting process is about separating aluminum sheets by cutting them into pieces and making pockets and holes into aluminum plates. This means that the CNC router can remove desired material parts from both plates, sheets, and create products such as perforated panels, aluminum composite panels for cladding, etc. It is just about the right way of using the end mill cutting bit.
While cutting Aluminum products, it is important to have in mind that the procedure is not as same as plastic or woodcutting. These materials have smaller sweet spots for optimal feeds and speeds. This means that the cutter tool can break if the sweet spots are left out fast and can cause a poor surface finish. There is another important factor when it comes to using a CNC router for cutting Aluminum, which is called the stickiness factor. This material is a kind of metal that tends to stick to the cutting tools. This almost happens on the point where it welds itself to the tool. Once a gummy aluminum deposit is created on the cutting edges, the tool will no longer be usable. This is especially essential if the rotation rate is fixed on 20,000 RPM or more.
How to Manage Cutting an Aluminum Using a CNC Router?
As it is obvious, cutting aluminum has its unique complexities. It is not as same as the wood and precision for certain aspects is the key to obtain the best results. The first important thing to have in mind is taking the procedure slowly. The goal for most industrial cases is to complete the job with speed and quality. This does not apply to this type of machining process. When using a CNC router for an aluminum product, steady and slow removal of desired material is the main goal.
The next important step is choosing the right router bits and small diameter cutters to obtain better control over the product and gain higher precision on the process. Using two or three flute carbide end mills is suggested due to their ability to have greater spindle speed on the machine. When working with aluminum sheets, HSS and cobalt cutter are not required. Small tools often work better for this material. Aluminum is a soft metal; however, the cutter can be easily broken during the procedure. The 1 flute end mills which are popular for plastic will not overcome the job pressure. Since the aluminum material tends to friction weld itself on the cutter, it is recommended to have a smooth surface finish to reduce the possibility of potential damages. Another important note is that the operator must remove the produced chips very fast because they can break the expensive router bits because of being recut. This process must be continued until a high-quality result is achieved.
Rigidity is another important factor when it comes to cutting aluminum with a CNC router. Small routers and large professional industrial machines definitely have differences. Aluminum is a material, which requires more rigidity than wood and plastic. Using tools that have longer bits can increase the advantage of the workpiece. When buying bits, it is important to keep an eye out for end mills that have stub ends and they should be kept short in the collet. Some manufacturers use aircraft cable and steel pulleys to add extra tension to the bridge and some others add extra ball screws and bearings to enhance their machine’s rigidity.
Another important step is to calculate and utilize the suitable and right feed rate to achieve better results. Predicting and calculating this can be very challenging. However, they are some starter standards that utilizing them can help to find the optimal feed rate in a short amount of time. For example, the cutting speed for aluminum in the case of the carbide tool is about 1,500 surface feet per minute at the highest point, and 1,000 at the lowest.
AS told the Aluminum metal has stickiness factor in its physical properties. The stickiness of the material can be controlled by putting it in oodles of lubrication. Some manufacturers recommend using oil mist as a lubricator. If an upgrade is required, then installing one is definitely recommended. It is not hard to install and it only needs a kit, compressed air, and oil. However, they are other alternatives available for the purpose. One of the most common systems is using lubricant sprays. This system can be challenging for machines that have a downward exhaust. In this type of routers, tons of air will be blown around the tool without actually reaching the cutter. It can be very tricky to have perfect spraying around the air blast. Another method is using cutting wax, which can be applied to the cutting surface. Using this method can solve the issues for downward exhaust machines and works perfectly for the process that requires single or shallow Z depth. If the routing needs more depth, it is recommended to get the lubricant further down by reapplying it in the recent cut channel.