Parameter 1860 is a bit-datalen (axis-specific) parameter used to define the checking distance for the reference position return operation.
On many FANUC controls, Parameter 1860 works in conjunction with Parameter 1850 (grid shift) and Parameter 1851 (reference position shift). It determines the range (travel distance) the axis must move to verify that it has correctly reached the machine's reference (home) position after a deceleration signal from the deceleration dog.
Symptoms:
Solution: Increase 1860 by 10–20% increments. Also verify that the motor torque limit (parameter 1640/1641) is adequate. fanuc parameter 1860 full
When setting Parameter 1850 (grid shift), P1860 must be larger than the correction amount. Example:
Fanuc Parameter 1860 is a servo parameter that sets the time constant (in milliseconds) for the first-order lag filter applied to the velocity command during cutting feed (G01, G02, G03) operations.
In simpler terms, it tells the servo amplifier how quickly to ramp up the motor’s rotational speed (acceleration) or ramp down (deceleration) when the CNC sends a move command while a cutting tool is engaged with the material. Solution: Increase 1860 by 10–20% increments
After replacing a servo motor or ballscrew, the machine shakes during G01 moves. Fix: The new components have different inertia. Calculate the new inertia ratio (parameter 2047/2048) first, then reduce 1860 by 20% as a starting point, then fine-tune upward.
Before making any change to Parameter 1860, back up all your parameters. One typo can disable the machine.
Method 1 – Punch to computer (RS-232): Method 2 – Memory Card (if equipped):
Method 2 – Memory Card (if equipped):
Method 3 – Manual documentation: Photograph the parameter screen for 1860, 1850, 1851, and 1815 (APC/APZ settings).
A 4th or 5th axis rotary table has high inertia. Setting 1860 too low on the rotary axis will cause "clunking" on start/stop. Fix: For a rotary axis, start with 1860 = 150 ms. Increase until motion is smooth, even if it slows indexing.