In practice, for direct drive systems: $$ 1860 = \textReference Counter (1821) \div \textScrew Pitch (in pulses) $$ (Note: This varies heavily depending on whether the machine uses a Decimal Input method or the older Integer Input method.)
When users search for "Fanuc parameter 1860 full," they often need to calculate a value that completely moves zero by a known amount. Here is how to do it correctly.
This article provides a comprehensive breakdown of FANUC Parameter 1860, explaining its function, how it interacts with the control system, and how to configure it correctly. What is FANUC Parameter 1860?
handles small mechanical "grid shifts" for fine-tuning, Parameter 1860 handles the primary data offset for the absolute detector. Tool Change Alignment : On some machines, if the
If 1850 = 0, bell-shaped ACC/DEC is effectively disabled, and 1860 behaves as a standard linear time constant. fanuc parameter 1860 full
The CNC will likely show an alarm (e.g., PS100). This is normal. Press the [SYSTEM] key. Press the [PARAM] soft key. Locate Parameter 1860: Type 1860 and press [NO. SEARCH] .
Achieving high-precision machining on a Fanuc-controlled machine tool requires more than just a rigid structure; it requires precise control of servo movement. One critical, yet often misunderstood, parameter in the servo adjustment suite is .
Modifying servo parameters can cause machine crashes if done incorrectly. Proceed with extreme caution and ensure no operators are inside the machine envelope.
Parameter 1860 is defined in FANUC manuals as the (or Position Feedback Move Amplitude per Motor Revolution). In practice, for direct drive systems: $$ 1860
This parameter sets the number of pulses required to move the axis by one unit of detection. It is part of the "Calculation of Detection Unit" formula. The CNC uses this value alongside the gear ratio and ball screw pitch to determine the "Detection Unit" (the smallest moveable distance the CNC recognizes).
If your system uses a high-resolution detection unit of , entering 10000 sets a physical deviation limit of only 1.0000 mm. Step-by-Step Guide to Changing Parameter 1860
The Ghost in the Machine: Understanding Fanuc Parameter 1860
As the servo motors move, the 1860 value fluctuates to reflect the continuous stream of data coming from the pulse coders. Why It Matters to Technicians What is FANUC Parameter 1860
If you encounter an absolute pulse coder alarm (like Alarm 300), you must re-establish the reference position. Simply typing "1" into Parameter 1860 is usually not enough; the CNC must "see" the machine reach its physical home first. Step-by-Step Recovery Procedure: How to Enable Parameter Write Enable (PWE) on a Fanuc CNC
The machine cuts perfect straight lines but oval arcs. This is often a mismatch between 1860 and the acceleration for the orthogonal axes. Ensure that the 1860 values for X and Y (or X and Z) are identical for circular moves. Uneven acceleration distorts circles into ellipses.
If the machine recently underwent a motor or encoder replacement, the loop gain parameters (such as Parameter 1825) might be set too low. If the position loop gain is too low, the servo responds sluggishly to commands, generating a naturally larger deviation that breaches the 1860 threshold. Best Practices and Factory Guidance