converted cordless drill to corded drill - only works once
Possible causes are either the drill's electronics or the power supply's electronics.

The Drill:


You're supplying a fixed voltage and a fixed current limit and the drill measures the voltage, sees the voltages fall of the cliff due to the high current draw, assumes it's a low battery and turns the motor off to stop over discharging the cells
Your supply is too good from the PSU, so the current is high and the voltage is high, this confuses the drill and causes some safety lockout


The Supply:


The supply isn't used to getting so much noise back from the supplies, it's erroring out with all the back EMF from the motor
The current draw is too high, safety factors cut in, such as over current lock out etc (though this would probably happen as you turn the drill on and the motor tries to spin up)