If it's from a drill you will find it somewhere less than 1ohm so you have no chance of running from a 3.3 amp supply. The stall-start current is way too high for your PSU, as DC42 suggests.
However you could try fitting a 50 watt halogen bulb in series with the motor and also an SPST switch across the bulb to shorten out the bulb. When you power up the systems the bulb will glow bright, the motor will pick up speed and the bulb will dim. When the motor is running as fast as it can with the bulb still in circuit you then operate the switch to shorten out the bulb and the motor will run up to full speed. In effect you have a resistance controlled soft-start.
There is a well established standard for the 4 pin PWM fan output on Motherboards.
The PWM output is open collector BJT or FET so needs to be pulled up externally to 3-5 V. The PWM frequency should be from 21-28 kHz and from 20% to 100%. The reason the PWM does not go below 20% is that many fans will not start or run at the lower speeds. The computer BIOS will normally start the fans at 100% for several seconds on power on to get them started, then backoff to temperature controlled speeds. Some BIOS's will allow you to set a minimum fan speed higher than 20% or to set 0% to turn the fan off completely.
The fan PWM controller is also responsible for counting the Tach signal, this is used to detect slow or stalled fans. If you don't enable this (supply the Tach signal to the controller) you might find your fan controller continually raising the speed of the fans. The solution is of course to feed the signal from one fan back to the motherboard controller.