I got a DEWALT Bare-Tool DCD760B 1/2-Inch 18-Volt Cordless Compact Drill/Driver in April 2014
It died a year and a half later. I just got another 18Volt drill* from Amazon and put a sticker on it that said "dead".
Two weeks ago a guy with no college education but dozens of electronics patents, wanted it to take it apart.
Today he showed me how the fan lugs anchor between the steel laminate core and use space at a larger diameter than the rotor and brushes... to make the motor shorter.
It seems to completely assemble without rotor and brushes for easy troubleshooting.
*I also got a 20Volt drill in 2015 that swaps batteries with the chainsaw. The 20Volt batteries last much longer than the 18 Volt.