AccuWeb EVO 150, Instruction Manual

Page: 88 / 137

AccuWeb
®
Linear Actuators 86
Actuators with potentiometer feedback (MT, SF, and HF) – POTENTIOMETER
REPLACEMENT:
If the position potentiometer has failed, replace the potentiometer with the following procedure:
1) Remove the actuator from the machine.
2) Remove the side covers from the drive box.
3) Manually position the actuator to the center of its stroke. Refer to the following table for the
correct distance from the end of the end cap (barrel) to the end of the thrust tube.
Actuator Model
Servo-Center
Length
MT-1 1 1/8" [28.6mm]
MT-2, SF-2 2 13/16" [71.4mm]
MT-4, SF-4 4 11/16" [119.1mm]
MT-6, SF-6 6 13/16" [173.0mm]
HF-3 4 11/16" [119.1mm]
HF-6 8 7/16" [214.3mm]
4) Loosen the attaching bolt and remove the potentiometer mounting bracket.
5) Remove the worm gear from the potentiometer shaft and remove the defective potentiometer
from the mounting bracket.
6) Install a new potentiometer on the mounting bracket and connect the wiring to the same
terminals of the new potentiometer as the old potentiometer.
7) Install the new potentiometer onto the mounting bracket and reinstall the worm gear on the
potentiometer shaft.
8) Turn the potentiometer to its CW mechanical stop.
9) Rotate the potentiometer exactly five turns CCW.
10) Reinstall the mounting bracket into the drive box. Leave the mounting bolt loose.
11) Adjust the position of the mounting bracket so there is a small amount of backlash between
the potentiometer worm and worm gear.
12) Tighten the mounting bolt.
13) Lubricate the worm and worm gear.
14) Reinstall the side covers on the actuator.
15) Press the SERVO-CENTER button and verify that the actuator drives to the correct position
and stops. Refer to the previous table for the exposed length of the thrust tube.
16) Reinstall the actuator in the machine.
Actuators with limit switches (MM, MME, MN, and MNE) - LUBRICATION:
1) Remove the actuator from the machine.
2) Extend the actuator to its Out end-of-travel limit.
3) Remove the side covers or body extrusion by removing the hex-head screws.
Note: For some models this may require removing the thrust tube rod end and end cap.