if you want that then the SuperPID is the thing (it requires some delicate surgery on your dewalt), but pretty slick. The coolest part is of course you have real PID control on your motor speed with sensing so as the part bogs down in material it will increase power to maintain the speed.
I read the topic but I didnât fully understand it. I am using this cnc shield and I have a 27Volt power supply. how should I make the connection so that I can turn the router on and off from the cgode I created?
Can you draw a wiring diagram for me?
Thank you 
Even though I tried all the steps
when I type the m3 start command, the engine does not start, and when I turn the engine on manually and type the m5 stop command, the engine stops.
This shows that my relay is actually working correctly.
I wonder where am I doing wrong?
The engine I use is Bosch GKF550
