End mills / Drill bits for aluminium

[Jonathan]

People too often confuse torque and power. They are related by a simple formula, but represent completely different things. Power is torque times speed (if you use the correct units).

With the correct control (which is not necessarily easy) you can get rated torque at *any* speed from the spindle. That doesn't help you much though, as at 1000 rpm you're at 1/24th of the rated speed, so at rated torque you have 1/24th of the rated power - so less than 100W.

The problem with drilling is you generally need *more* torque, so just getting the rated torque (about 1Nm) isn't so helpful. You can use tricks like the one you linked to and exceed the ratings of the motor to get more torque (e.g. just apply a higher voltage at low speed), but I certainly wouldn't recommend it when this is something you need to do regularly. That's how I managed to drill several hundered 8.5mm holes with a carbide drill using my spindle:

Homemade CNC Router aluminium bed drilling with coolant - YouTube

I also occasionally drill aluminium with the spindle at around 4000rpm with a 4.2mm HSS drill, but I wouldn't recommend doing it regularly.