User manual

Barrett Technology, Inc.
BA4-310 System User Manual Version 1.1
44
[ ] 6. Take one end of the other 2286mm 1
st
-stage cable and attach the brass lug to the
termination closest to the vertical support on the left pulley.
[ ] 7. While this pulley remains immobilized wrap the cable 10 turns around the pulley. Be
careful not to cross the wraps or damage the cable. While wrapping each turn, keep
previous turns tight and in position with your fingers or a piece of tape. Temporarily
tape the wraps in place when done.
[ ] 8. Place the brass lug at the free end of the cable into the termination slot on the outer
motor pinion. Make sure the lug is fully seated in the termination, then, keeping the
inner pinion stationary, wind the free cable onto the outer pinion with a right-hand pitch
by rotating only the outer pinion. Maintain a slight axial force on the outer pinion
during this step so that the seam between it and the inner pinion does not open.
[ ] 9. Lubricate (lightly) the pre-tensioning worm with appropriate grease. Barrett
Technology, Inc. recommends Mobil-1 synthetic grease. Insert the worm into the outer
motor pinion and turn it with the hex wrench (thereby rotating the tensioner
mechanism) until any slack in the free cable length has been taken up on the motor
pinion.
[ ] 10. Very slowly and carefully rotate Joints 2 & 3 while guiding the cables from all pulleys
surfaces onto all grooved pinions. Rotate the joints slowly to one motion stop and back
to the other. This step adjusts the wide pitches on the pulley surfaces to match the
corresponding tight pitches of the pinion grooves.
CAUTION !!!: use extreme care when moving these joints if you removed the J2 stops
for access to the 2
nd
-stage cables
CAUTION !!!: make sure the motor axis 4 electrical wires stay clear of the mechanical
cables when moving J2 & J3 before the shoulder wire guard is re-
installed
[ ] 11. Finally, tension the cable circuit by adding a pre-tension slightly less than ½ the 1
st
-
stage cable’s breaking strength. This is accomplished by: applying 0.68 N-m [96 oz-in]
to the lubricated pre-tensioning set screw using the torque driver provided with your
system,
slowly
moving the joint through its full range of motion, applying the specified
torque again to remove the new cable slack, and repeating this process until moving the
joint no longer reduces the tension in the cables (
i.e.
the full pre-tension has been
propagated throughout the cable circuit).
[ ] 12. Replace the Joint 2 stops with their rubber inserts (if you removed them when cabling
the 2
nd
-stage), the shoulder wire guard, and the two shoulder covers.