G50 and G51 Scaling Mode
Overview
- The shape defined by a part program can be enlarged or reduced according to a required scale.
Command Format
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Syntax:
G51 X.. Y.. Z.. I... J... K... P...
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X.. Y.. Z.. [opt] - Center of Scaling
- The center of scaling is defined by X, Y, and Z (absolute position in Local Coordinate System)
- If XYZ values are not provided, scaling origin will be at the Local Coordinate System origin point (0, 0, 0).
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I... J... K... -Scaling with different ratios per axis- I.. - Scaling along X axis
- J.. - Scaling along Y axis
- K.. - Scaling along Z axis
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P... - Scaling with even ratio along all 3 axes - G51 P2.0 ← Twice the size
- G51 P0.5 ← Half the size
- Negative scaling values
- Negative values mirrors the part
-
Syntax:
G50 - Cancels scaling if active
Details ¶
- If there are P and I J K scaling values specified in the same line, the P argument takes priority and I J K will be ignored.
- If any of the scaling values are 0 = an error will be generated.
- Does not scale the feed rate
- Only scales the XYZ positions at most
- E position will be scaled by the highest scaling ratio (if using I J K) or the same as the P ratio
- A,B,C,U,V,W will be scaled the same as the E axis
- Effects on offsets
- Doesn’t scale tool offsets or tool compensations
- Does not scale coordinate offsets
- Does not scale rotational offsets or degrees
- G02/G03 arc behavior
- requires scaling to be applied uniformly to the currently active plane (G17/18/19)
- For example, if Arc is on a plane XY, I and J scaling values have to be identical (can be negative). If the arc is a helix, the K value can be different to make the helix higher or lower.
- Mirroring
- Incompatible with Cutter Radius Compensation
- Commands not allowed:
- G51 P0 - scaling ratio 0
- G51 I5 J5 K0 - scaling ratio 0
- Scaling at LCS origin:
- G51 P5 - Scales the part x5 times along each axis
- G51 I2 J3 - Scales the part x2 X direction and x3 Y direction
- G51 J-1 - Mirrors the part along Y axis
- G51 P-2 - Mirrors and scales the part x2 (flips the part 180 degrees around the origin point)
- Scaling with the center at some position
- G51 X10 Y10 P5 - Scales the part x5 around (10, 10) position
- G51 X20 Y10 I-1 J2 - Mirrors the part along X axis, scales x2 along Y axis, scale origin at (20, 10) position.