Parameter 1860: Fanuc

Many machinists confuse these two. Here is a simple memory aid:

Never use 1860 to compensate for a misaligned mechanical zero. That is what 1850 is for. Incorrectly raising 1860 to force alignment will only lead to erratic behavior and possible drive failure.

For rotary tables (4th/5th axes), set 1860 in degrees per minute. A typical range: 1000–3000 deg/min. Because rotary inertia is lower than linear axes (usually), higher 1860 is acceptable, but watch for mechanical lash.

Cause: Excessively high 1860 causing limit-cycle oscillation near the setpoint. fanuc parameter 1860

Solution: Immediately reduce 1860 by 30-40%. If the buzz disappears, re-tune from a lower baseline.

PARAMETER (REFERENCE)     1860
AXIS   X      Y      Z      B
DATA   300    300    300    2000

Note: On older controls (0i, 16i, 18i, 21i), 1860 may be integer only; newer controls allow decimal values for fine adjustment.

If Parameter 1860 is set too high, the machine will take too long to speed up and slow down. While individual moves might only lose fractions of a second, over an entire shift, this "lazy" acceleration can significantly increase cycle times and reduce production output. Many machinists confuse these two

⚠️ WARNING: Always back up your machine parameters to a memory card or USB stick before making any changes. Incorrect parameter settings can cause the machine to behave unpredictably.

Q1: Can Parameter 1860 be changed while the machine is running?
A: No. Spindle parameters require a power cycle. Changing 1860 without reboot has no effect.

Q2: Does 1860 affect normal spindle speed (Sxxxx) operation?
A: No. 1860 only applies to orientation mode (position control). Speed control remains unaffected. Never use 1860 to compensate for a misaligned

Q3: What happens if I set 1860 to zero?
A: The spindle will not orient at all – it may drift or refuse to complete M19. Never set to zero intentionally.

Q4: Why does my OEM recommend a specific number that seems too high?
A: OEMs often set 1860 for maximum stiffness to guarantee tool change reliability, even at the cost of a slight vibration. You can usually reduce it by 10-15% for smoother operation, but confirm with them first.

Q5: Does parameter 1860 exist on Fanuc Robodrill?
A: Yes, on Robodrill with Fanuc 31i-B5. Default is typically 1200 for BT30 spindles.