Machine Zero | CNC Programming | 100% Support

Definition:
Machine Zero is the fixed origin point of the CNC machine, set by the machine builder.
It is the home position where all axes (X, Y, Z) are at their maximum limit or predefined origin.
Key Features:

• It never changes.
• It’s defined by hardware limit switches or encoders.
• When you start the machine, it must be homed so the control knows the true axis position.
• Usually set at the farthest positive travel (X+, Y+, Z+).
  Example:
  When the spindle is at the extreme top and the table is fully to one corner — this is the machine zero
  position.
  Graphical Concept:
  Z+
  ↑
  | (Spindle head)
  |
  Y+ ←────┼────→ X+
  |
  |
  +——————–> Machine Zero (M)
  2. Reference Zero (R)
     Definition:
     Reference Zero (or Home Reference Point) is a known repeatable point on each axis that helps the
     CNC machine find its Machine Zero after power-on.
     Key Features:
• It is the intermediate step between unknown start and Machine Zero.
• Located using limit switches or encoders.
• When the machine is “homed,” it moves each axis to its reference point to establish
  positional awareness.
  Example:
  When you press the “HOME” button, the axes move until they reach their reference points — from
  there, the machine knows how far it is from Machine Zero.
  Graphical Concept:
  Z+
  ↑
  Reference Zero (R)
  |
  |
  +———-> Machine Zero (M)

1. Work Zero (W)
   Definition:
   Work Zero (also called Program Zero or Part Zero) is the origin point for the workpiece — chosen by
   the operator or programmer.
   Key Features:

• It’s set using work offsets like G54, G55, etc.
• It’s relative to Machine Zero.
• Programmers use this as the base for all machining coordinates.
• Usually located on the top surface or corner of the workpiece.
  Example:
  If you clamp a metal block on the table, you can set Work Zero (W) at the top-left corner of that
  block.
  Graphical Concept:
  Z+
  ↑
  | Spindle
  |
  | Workpiece
  | + (W) ← Work Zero (G54)
  |____|
  |
  +———————> Machine Zero (M)
  Summary Table
  Point Name Symbol
  Machine Zero M
  Reference
  Zero
  Work Zero
  R
  W (G54
  G59)
  Set By
  Machine Builder
  Machine System
  Operator /
  Programmer
  Changes?
  Fixed
  Fixed
  Changeable
  Purpose / Use
  Absolute origin of the CNC
  Helps find machine coordinates
  after startup
  Used as origin for part program