With compliments of "mybuild14" A useful pictorial reference: The accepted Axis format for CNC's. Many Thanks Gray
Thanks Gray for putting this in the correct location. Since I am new to CNC it helps me understand what axis corresponds to the G-Code input. I have a printed copy posted beside my OX for reference. Thanks, Dave
As a quick trick, being left handed, I hold my left hand before me with the thumb pointing up (Z+), the index finger pointing away from me (Y+) and the middle finger pointing right (X+). The origin is where all three finger 'meet'. How you wire your machine, keeping the relation of the three axis correct, is up to you really. If you decide to wire your X as your Y and vice versa, the equivalent of turning your left hand 90 degrees clockwise so middle finger now points at you, Z (thumb) still pointing up, your origin goes from the lower (front) left corner to the upper (rear) left corner (and dimension limits transfer respectively). CAD, CAM and machine all work properly.
Thats very strange, ive been a cnc operator for 6 years and every machine ive touched is the opposite of that. Y axis is usually the shorter axis as the x is the longer. Right now i run a 3 spindle 5 axis gantry and the legnth of the gantry is the x axis.
As the same machine can be built in either a 2x4 configuration or a 4x2 configuration merely by adjusting the length of the rails, it become fairly clear axis length cannot be the determining factor. Standard convention dictates that when the operator is standing at the front of the machine (which means the side rails are to the left and right of the operator), X axis runs across in front of the operator increasing left to right, Y runs front to back increasing as it moves away from the operator, and Z goes up and down increasing as it goes up. This eliminates any possible ambiguity whether the machine is set up as a 2x4, a 4x2, or even a 3x3 layout.
Use the thumb, index and middle finger of your LEFT hand. Point thumb up, index away from you and middle bent to the right. Z is your thumb, positive is upward. X is your middle finger, positive, again, in direction finger points in (to the right). Which leaves Y as the index finger, positive pointing away from you. Obviously, you need to stand in front of your machine as Rick states. Conventions aside, nothing really stops you from wiring your steppers differently and sticking your OX to the wall BUT the three axis must keep their relationship for any of the software to properly control your machine. For what it's worth, if your Y steppers turn the part, a thick rod ideally, X moves tool parallel to the length (height) of the cylinder and Z is cutting depth: you have a CNC 'lathe' with any software and controller (just remember not to go too deep towards the center of that solid rod or thick wall cylinder as there is no spoil board !)
