Machine Tool Coordinate Systems, Axis Conventions

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tblough
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Machine Tool Coordinate Systems, Axis Conventions

Post by tblough »

Just though I'd post this here as a reference for the DIY'ers when setting up their machine tool coordinate systems. All illustrations were taken from ISO 841:2001(E) Industrial automation systems and integration — Numerical control of machines — Coordinate system and motion nomenclature
RightHandCoordinateSystems.PNG
Z-Axis
The Z axis is parallel to the principal spindle of the machine.
  • On machines used for milling, grinding, boring, drilling and tapping, the spindle rotates the tool.
  • On machines such as lathes, cylindrical grinders and others which generate a surface of revolution, the spindle
    rotates the work piece.
  • For cutting and forming machines, the Z axis shall be perpendicular to the work-holding surface.
  • For coordinate measuring machines, the Z axis should be collinear with the acceleration of gravity vector (i.e.
    perpendicular to the surface of the earth).
X axis
Where possible, the X axis shall be horizontal.
  • Machines with rotating tools
    • Horizontal Z axis: Positive X shall be to the right when viewed in the negative Z direction.
    • Vertical Z axis, single column: Positive X shall be to the right when viewed from the front of the machine into the
      column.
    • Vertical Z axis, gantry type: Positive X shall be to the right when viewed from the principal spindle to the left-hand
      gantry support.
  • Machines with rotating workpieces
    • The X axis shall be radial and parallel to the cross slide. The positive direction shall be away from the axis of
      rotation.
  • Machines with no spindle
    • For cutting machines, positive X shall be parallel to and in the principal direction of cutting.
    • For coordinate measuring machines, positive X shall be defined by the manufacturer.
Y Axis
Positive Y shall be in the direction to make a right-hand set of coordinates

Examples
Attachments
GantryMill.PNG
VerticalMill.PNG
HorizontalBoringMill.PNG
HorizontalMill.PNG
KneeMill.PNG
VerticalBoringLathe.PNG
TurretLathe.PNG
EngineLathe.PNG
Cheers,

Tom
Confidence is the feeling you have before you fully understand the situation.
I have CDO. It's like OCD, but the letters are where they should be.
cnckeith
Posts: 6928
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Re: Machine Tool Coordinate Systems

Post by cnckeith »

thanks Tom!

here is a good link to go with this info.

https://www.autodesk.com/products/fusio ... made-easy/
Need support? READ THIS POST first. http://centroidcncforum.com/viewtopic.php?f=60&t=1043
All Acorn Documentation is located here: viewtopic.php?f=60&t=3397
Answers to common questions: viewforum.php?f=63
and here viewforum.php?f=61
Gear we use but don't sell. https://www.centroidcnc.com/centroid_di ... _gear.html
tblough
Posts: 3028
Joined: Tue Mar 22, 2016 10:03 am
Acorn CNC Controller: Yes
Allin1DC CNC Controller: Yes
Oak CNC controller: Yes
CNC Control System Serial Number: 100505
100327
102696
103432
7804732B977B-0624192192
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Boston, MA
Contact:

Re: Machine Tool Coordinate Systems

Post by tblough »

As Marc pointed out in the copy of this thread in the All Others forum, Motion is relative to the "tool" and positive directions are in the direction the tool would move. On machines where the table moves, "negative" table movement (denoted by the ' on the axis designation) is "positive" cutter movement.

On a knee mill, positive X is the table moving to the left (cutter "moving" to the right), positive Y is table moving away from column (cutter "moving" towards the column).
Cheers,

Tom
Confidence is the feeling you have before you fully understand the situation.
I have CDO. It's like OCD, but the letters are where they should be.
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