When it comes to machining the metals like aluminum, most people think of using high-end milling machines, and there is no denying the fact that such machines are able to carry out really complicated work. Those spindles can spin the cutting tools at a speed comparable to the finest drills. However, a CNC router comes with a spindle that operates at a higher speed than the conventional mill. These are mainly utilized for cutting wood for operations like slot cutting, rounding edges, and lettering.
Though it isn’t always particularly mentioned, the CNC routers are able to cut aluminum, as well. Here is taking a close look at how CNC routers can cut aluminum and the tips to help you do it effectively.
Can a CNC router cut Aluminum?
Machining metals like aluminum using the CNC router is possible with almost all CNC routers. You can easily cut aluminum by matching this material with the right feed rate and end mill bit.
It is important to keep in mind here that cutting refers to the separation of aluminum sheets into pieces and making pockets into aluminum plates. So, basically, using a CNC router you can remove material from both aluminum plates and sheets. It just needs the right use of the end mill cutting bits.
While cutting aluminum, you need to remember that it is not the same as plastics or wood. Aluminum has smaller sweet spots for speeds and optimal feeds. The cutters start to break if the sweet spots are left and the wear out fast. The resultant surface finish is poor. You also need to consider the stickiness factor for aluminum. It is the kind of metal that tends to stick to the tools. It sticks to the tool to a point where it practically gets welded on to it.
Aluminum deposition on the cutting edges means that the tool is not going to survive for too long, especially if you use it at 20,000 RPM or more. If you can navigate through these challenges, you can use any router to successfully cut aluminum.
How to cut aluminum using a CNC router?
As mentioned earlier, cutting aluminum has its own intricacies. It is not the same as cutting wood, and you need to be a lot more careful about certain aspects. The first thing that you need to keep in mind while cutting aluminum is that you need to take it slow. The goal in any business is usually to get the job done with quality and speed, but not in this case. Slow and steady removal of material is your goal, when trying to use a CNC router on aluminum.
Your next step is to choose the right router bits and small diameter cutters to get greater control over the material and attaining higher precision at work. A suggestion here is to use two or three flute carbide end mills because they let you have greater spindle speed on the router. When you are working with aluminum, you don’t need HSS and cobalt cutters.
After this, make sure to calculate and use the right feed rate for greater precision in your work. Deal with the stickiness of aluminum by putting in oodles of lubrication. Remove the chips fast because you would not want to break your pricey router bits because of re-cutting aluminum chips. Continue with the process carefully and you will be able to cut aluminum with CNC routers with as much precision as you want.
Tips for cutting aluminum using CNC router
Though it is possible to cut aluminum using CNC routers, it does not happen in the simple and straightforward way as cutting wood. So, use the tips given below, if you are planning to use your CNC router for cutting aluminum.
1. Do not rush the process
Just because a CNC router is able to cut aluminum, it does not mean that you can hog out major aerospace parts such as wing spars. You need to slow things down to be successful. You don’t need to slow down the speeds and feeds, but the rate of removing the material will be a lot less than what you can achieve with a purpose-made CNC mill. Calm down and let your machine do its thing.
2. Use a calculator for speeds and feeds
With aluminum, you are most likely to hit the limits of your machine’s capabilities. It is not a child’s play to cut aluminum with CNC routers. You will find speeds and feeds calculator online that you can use to figure out the right numbers for both of these important criterions.
3. Use cutters of smaller diameter
You need to bump the RPMs up while cutting aluminum, and a good way of doing that is by using small diameter cutters. You can go for ½ inch end mills, but your best bet is to go down to ¼ inch at the maximum and even less. As you are going for smaller diameters, you need rigid cutters so that tool deflection does not give you any trouble.
4. Keep a close watch on cutting depths
A deeper cut and going close to the slot where the cutter goes in makes it hard for you to clear out the chips at the bottom of a hole. You will need more passes for cutting down to the much-needed depth and opening up the shallow depths for greater access. If you are using a material with a thin layer of aluminum that is fused to it, just set your sheet with its aluminum side up. It will help you in clearing away the aluminum from the cutter quickly, and you can carry on with your work.
Using CNC router on aluminum is possible with almost all kinds of routers. It is all about matching the capacities of the machine to the sweet spot speeds and feeds requirements of aluminum through a clever selection of cutting and tooling parameters. Put enough lubrication and clear the chips out, and you are good to go.