Lateral play (slop) – equal (machine error)
Plot
The plot has a symmetrical peach/stone shape. Lateral play type plots are unaffected by the machine feedrate, however they are affected by direction. If clockwise and counter-clockwise runs are displayed at the same time then one plot will appear inside the other. Which plot appears inside the other depends on the whether the Lateral play error has a positive or negative value. The plot shown has equal positive Lateral play in the Y axis causing the clockwise plot to appear inside the counter-clockwise plot.
Diagnostic values
Lateral play is quantified in the following format for the X and Y axes:
Lateral Play (µm)
X +0.9 -0.7
Y +30.9 +30.9
The values quoted by the diagnostic software for Lateral Play are quoted in either microns or inches.
In this case Equal Lateral Play is present because Y is equal to Y.
Cause
The main cause of Lateral play is play or slop in machine guideways. This allows the axes of the machine to move at right angles to their guideways as the axis reverses. This should be contrasted with a backlash step, which is also caused by play, but in line with the axis. As seen on a Ballbar circular test, backlash is a radial error, whereas lateral play is a tangential error.
Effect
The machine will cut non-circular interpolated holes.
The machine will exhibit general positioning errors in the axes that are affected by Lateral Play.
Action
Adjust or renew the guideways of the machine to eliminate any play or slop that is present. See also Lateral play-slop unequal.