I recently salvaged a 3.6V motor from a cordless drill that had a dead battery that wouldn't hold a charge. I have an identical drill with a battery that does hold a charge.
I've been trying to use the salvaged motor but have been having issues. When I hook it up to my power supply @ 3.6V it does nothing but use power. If I give the shaft a quick turn, then it begins to spin quickly. Since I salvaged it a while ago before tossing out the rest of the drill I can't study the inside. I did open the identical drill I have and didn't find anything particularly interesting before putting it back together and there's no special gearing inside.
I tried increasing the voltage a little but it still doesn't spin without giving it a little help to start.
What could cause this? I know my other drill doesn't get any help-- it actually has force applied against it as it starts sometimes.