I am having trouble setting the limits I have just bought the cnc3040T-DJ and I have installed the Mach 3 that came with it now when I try to set the limits do I have to input the table size, the range of travel of the x, y & z or the size of the work piece and can someone tell me which of the four corners is the home point. One last thing for now is do I have to install limit switches in the machine as when I try the setup the homing while watching the video the 3040 does not stop it get to the limit of travel for the x axis and just keeps trying to keep moving and making a terrible noise and I have to hit the estop please help 

I have the exact same questions. Can someone please answer this gentleman's questions.

I've searched the forums for a couple hours now and found this video. It helped me a lot! It should help you out too. http://www.machsupport.com/videos/  click the "Homing, Limits, and Offsets" video.