HB wrote:Because the motor isn't well ventilated and the grinding chamber acts like a stopper/heatsink.

And because the motor used in most grinders will spin very fast without any coffee in the grind chamber. This in turn will generate a lot of heat.
A DC motor, as used in electric automobiles, does not suffer from this problem.

While i try to convince myself that my few hundred dollar espresso grinder should be capable of grinding espresso (and i grind quite fine) to adjusting for a brewed pot, and back to espresso - it really isnt practical.

while it can be done, and im sure even easier with a guitar winder, the minute adjustments after the large changes arent worth it IMO.

i can count 35 cranks to go from espresso to drip. so, 35 back, right? no.. the burrs dont line up the same, so it take quite a few shots to tweak back to proper grind.

too annoying for my coffee addict patience! i either use a whirly blade for french press, or my whirly blade cuisinart for drip. im not as particular for brewed, i guess.

PS - i always crank with the grinder empty and off (its always empty anyway except when in use), and fine tune with it on to hear the burr movement. no need to have it on, except for the 28 seconds it takes to grind.