TL;DR

Joint noise on the R-2000iC points to worn harmonic drive bearings or insufficient lubrication. Check grease interval compliance first before opening any joint.

What you might see

grinding or clicking noise from a specific joint during motion
noise repeats at a consistent point in the cycle
joint temperature elevated compared to other axes
vibration detectable at the wrist during the noisy move

Likely causes

Tap to mark as ruled out

Worn harmonic drive or cross-roller bearing in the joint from extended service
Insufficient or degraded joint grease causing metal-to-metal contact
Foreign object or metal debris in the joint from a previous collision
Incorrect grease type used during a previous maintenance event

Required tools

FANUC-specified joint grease and manual grease gun
IR thermometer
Grease collection container (for sample at drain port)
LOTO kit
FANUC R-2000iC Maintenance Manual (lubrication schedule)

Safety first

Lock out the controller before greasing any joint. An unexpected motion during greasing can trap a hand in the joint.
Never use non-FANUC-specified grease in the robot joints. Incompatible grease types react chemically and can accelerate bearing failure.
If a joint rebuild is required, that work must be performed by a FANUC-certified technician. Incorrect assembly of the harmonic drive can cause catastrophic joint failure.

Procedure

8 steps · ~30 min

1
Identify the noisy joint by isolating each axis in T1 manual jog mode. Move each axis individually and listen for the noise source.
2
Lock out the controller and check the grease nipple for the noisy joint. Confirm the grease type and quantity match the FANUC R-2000iC lubrication schedule.[1]
3
If the joint is overdue for re-greasing, pump the specified grease quantity into the nipple while manually jogging the joint to distribute the grease.[1]
4
Re-test after re-greasing. If the noise reduces or disappears, inadequate lubrication was the cause.
5
If the noise persists after correct re-greasing, check the joint temperature with an IR thermometer. A persistently hot joint confirms bearing wear beyond lubrication recovery.
6
Take a grease sample from the drain port of the noisy joint and inspect for metal particles. Metallic contamination confirms bearing or harmonic drive wear.
7
If metal is found in the grease or noise continues after lubrication, the joint drive component needs replacement. This requires a FANUC-certified technician and the correct joint rebuild kit.
8
Log the finding in the maintenance record. Premature harmonic drive failure can indicate a previous overload or collision event that should be reviewed.

Sources

FANUC R-2000iC Robotic Arm Maintenance Manual, FANUC
FANUC R-2000iC Robot Maintenance Manual, joint lubrication schedule and harmonic drive inspection procedures (general)
View source

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