Fanuc Parameter 1860 Full !!link!! 99%

Mastering Fanuc Parameter 1860: The Complete Guide to Axis Acceleration/Deceleration Time Constants

Key Characteristics:

• Axis-Specific: A separate 1860 exists for each controlled axis (e.g., 1860 for X, 1861 for Y, 1862 for Z, etc.).
• Unit of Measure: Milliseconds (ms). Typical values range from 20 to 500 ms depending on machine size and rigidity.
• Application: Active only during cutting feedrates (F-code moves). Does not affect rapid traverse (G00)—those are controlled by parameter 1620 and 1622/1624.

6. Troubleshooting Alarms Linked to P1860

Q4: What is the "full" default value for Parameter 1860?

A: Factory default is almost always 0. If you see a non-zero value, the machine builder or a previous technician set it.

Calculating the Optimal Value for Parameter 1860

There is no universal "perfect" number for 1860. It depends on your machine's mechanical design, motor torque, and the workpiece material. However, you can calculate a safe starting point.

What Does Parameter 1860 Do?

In semi-closed loop systems, the CNC counts feedback pulses from the motor encoder to determine position. When returning to a reference point (grid method), the reference counter counts pulses from a grid signal until it reaches the value set in 1860, then generates the reference point.

In simpler terms:

• 1860 = Number of reference pulses per motor revolution ÷ (Divider ratio set in Parameter 1820).
• It determines how many feedback pulses correspond to one full revolution of the motor after electronic gear calculation.

8. How to Change & Verify

Procedure (on FANUC control):

1. MDI mode → OFFSET/SETTING → Parameter Write = 1
2. Press SYSTEM → PARAM → search 1860
3. Enter new value for required axis (e.g., 1860 X 3000)
4. Cycle power or perform reference return twice to validate.
5. Test: Run G28 X0; multiple times → check position display repeatability.

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Relationship with Other Parameters

• 1815.1 (APC) : If =1 (Absolute encoder), Parameter 1860 is ignored.
• 1820 : Divider for encoder pulses (must divide evenly into 1860 × 1820 = total pulses/rev).
• 1850 : Grid shift value (compensates for minor grid-to-reference misalignment).
• 1881 : Coder pulse count (used with high-resolution encoders, may override 1860 logic on newer controls).