The original Dremels had actual speed controls; if the spindle loaded down, the motor power would be increased to restore the speed. Modern ones (at least as of

The original Dremels had actual speed controls; if the spindle loaded down, the motor power would be increased to restore the speed. Modern ones (at least as of a few years ago) were just constant power, so they indeed slow down as a load is applied. (Probably still a bad idea...)