CNC routers are frequently used with wood and acrylics, but they’re versatile enough to handle the demands of materials such as aluminum. The key to successful aluminum machining is adapting the process to accommodate its different characteristics.
Incorporate these tips to minimize the challenges and produce high-quality parts.
Calculate Proper Feeds and Speeds
As with most metals, the optimum feeds and speeds combination for aluminum is a more narrow range than that of wood or acrylics. Cutting aluminum requires a higher spindle speed that may push the outside limits of your CNC machine.
- Feed rates that are too slow can cause rubbing that reduces the lifespan of tools.
- Feed rates that are too fast can overburden the machine, resulting in breakage.
The old-school method of “playing it by ear” allows too much room for error. A feeds and speeds calculator will help you determine more precise rates.
Use Carbide-Coated Bits with Smaller Diameters
With the higher RPMs involved in cutting aluminum, high-speed steel and cobalt are not likely to be up to the task. Carbide is a more rigid material, making a preferable solution for bits.
Speedier machining rates also call for smaller diameter bits. The rigidity of carbide is another benefit here, as it will protect against potential tool deflection.
Maintain a Stable Temperature
Aluminum is more vulnerable to variations in temperature, causing waste as completed parts are out of tolerance. Use hardware and software that are capable of holding temperatures at an acceptable level.
Clear Chips Thoroughly
Aluminum chips have a certain “stickiness” factor that causes them to become essentially welded to the tool, resulting in poor quality work and excess wear and tear on machines.
- Don’t rely exclusively on dust collector systems. Check the machine faithfully to ensure chips are cleared out.
- Run a coolant mist or other lubricant through the machine to reduce the tendency of chips to stick.
Go Slow and Steady
There’s a temptation to save time by making deeper cuts, but this strategy can backfire by making it harder to clear chips. Stick with frequent shallow passes that allow greater control and better access for chip removal.
Reduce the Number of Flutes
Too many flutes can aggravate the chip problem by causing them to get packed in too tightly. Switch to a maximum of three flutes with aluminum machining. Increased space between the cutting edges makes it easier for larger chips to escape.
Our patented stacked aluminum machining process makes it possible to create perfectly finished parts without the cumbersome traditional stacking, drilling and riveting.