[ \textParameter 1860 = \fracK_v \times JT_\textrated \times 100 ]

Introduction: The Hidden Key to Precision Machining In the world of CNC (Computer Numerical Control) machining, few things are as critical—or as misunderstood—as spindle orientation. Whether you are performing rigid tapping, automatic tool changing (ATC), or using a C-axis indexing feature, the spindle must know exactly where it is in rotational space. For Fanuc-controlled machining centers and lathes, one parameter stands out as the gatekeeper of this function: Fanuc Parameter 1860 .

A: No. 1860 only applies to orientation mode (position control). Speed control remains unaffected.

If you have ever encountered an alarm such as "PS0405 – No Spindle Orientation" or noticed that your tool change arm misses the pull studs by a few degrees, you have likely entered the realm of Parameter 1860. This article serves as your definitive guide. We will cover what Parameter 1860 is, how it works, how to calculate its value, step-by-step modification procedures, common troubleshooting scenarios, and best practices from seasoned service engineers. 1.1 The Technical Definition Fanuc Parameter 1860 (often listed in manuals as N1860 or PRM 1860 ) is a position gain parameter specifically associated with the spindle orientation circuit . In simple terms, it tells the spindle drive (usually a Fanuc Alpha i series or earlier digital spindle amplifier) how aggressively to correct positional errors when orienting the spindle to a specific angular position (e.g., 0°, 90°, 180°, or 270°).

A: The spindle will not orient at all – it may drift or refuse to complete M19. Never set to zero intentionally.