One of the biggest complaints newbies have with CNC machines powered by the dewalt palm routers is the brushes wear out and need to be replaced. When one is using the router by hand the motor starts not running smoothly and an experienced wood worker can hear the brushes are about done. However, when left on a cnc it is harder to tell. Newbies often put the speed at fastest and this makes the brushes wear out faster.
So why not use a brushless router? Well because the only ones that are brusheless are the battery powered ones and it would suck to have the cut stop in the middle of a job. One can make an AC power adapter like this:
Cordless Power Tool Conversion 18VDC to 120/240VAC : 10 Steps (with Pictures) - Instructables
I also noticed the speeds for the battery powered dewalt are a bit fast?
DIAL RPM
1… 16000 rpm
2… 17500
3 …19100
4 …20700
5 …22300
6 …23900
7 …25500
The makita battery powered router goes slower 10K to 30K RPM and costs less.but one will need a 2mm thick shim to make it fit the Maslow4
Makita USA - Product Details -XTR01Z (makitatools.com)