JUKI RS-1 - Replacing the Ball Screw

Maintenance Guide
2-20
2-1-6 Replacing the Ball Screw
When replacing the ball screw, it is necessary to dismount the Z motor. When dismounting the Z
motor, reacquire the MS parameters related to the Z axis height and the laser. (For the items to be
acquired, see section 2-2, Re-adjustment after Replacing the Head.)
Replace the ball screw with the head dismounted from the machine.
or the [★] parts of the work procedures below, also refer to the work contents of “2-1-1 Replacing the
Head Unit”, “2-1-2 Replacing the Z-Motor”, and “2-1-4 Replacing the Timing Belt Z”.
If the shaft of which the ball screw is to be replaced is other than that at either end (i.e. L1/L8), it is
necessary to remove the Z-axis motors and ball screws of the shafts outside the target shaft.
(Example: When replacing the ball screw of L4, it is necessary to remove the Z-axis motors, belts and
ball screws of L1 through L3 shafts.)
1) ★ Remove the head unit according to the procedures of “2-1-1 Replacing the Head Unit”.
2) ★ Remove the head SV bracket.
3) ★ Remove the Z motor cable stay.
4) ★ Remove the T sensor bracket.
5) ★ Remove the Z motor and timing belt Z of the shaft of which the ball screw is to be replaced.
6) Move down the Z axis to the lower limit and remove the ball screw nut from the Z slide bracket.
7) Release the lock nut fixing the upper end of the ball screw.
∗ There is a set piece inside the hexagon socket setscrew. Be careful not to lose it when
removing the lock nut.
8) After pulling out the ball screw downward, temporarily release it to the φ10 hole of the spline
bracket, then pull out the lower end of the ball screw from the Z slide bracket and remove it.
9) Perform assembly in the reverse order.
∗ Assemble the ball screw nut so that the print is on the right side.
∗ The tightening torque of the lock nut should be 0.6N･m.
∗ The load when pushing (pulling) the Z slide bracket shall be 5N (0.5kgf) or less.
∗ Since there is little clearance of the nut holder (i.e. the block on which the ball screw nut is
mounted) between the shafts, check the interference by moving the shaft back and forth every
time you adjust each shaft.
10) Apply CG2 grease to the replaced ball screw.