Screwdriver Discoveries Part 2

I remembered yesterday that I have a cheap lab style power supply that I really haven't used for a few years, and I hooked it up the screwdriver. 

The reason for this was a fellow HAM had suggested in chatting with some other locals that these may have had drill motors in them and were potentially 6v. 

I rigged the antenna up with the power supply and started dropping the voltage.. all the way down to about 1.5v. It kept working until about that point, drawing around 1.7-2.1A. It slowed down nicely.

Up to this point, I'd been debating if I could just use a potentiometer, but this seems to not be a great way of doing it. The aforementioned fellow HAM had also suggested a pulse based control method. 

Doing some deeper research on DC motor control, it seems that this is the go. After doing some investigation into options, it dawned on me to take a step back.  I can buy a PWM DC controller  within the voltage and current specs for around $10. Not sure it's worth engineering a solution when I can buy one cheaper than I can buy parts to make my own.