User manual

Barrett Technology, Inc.

BA4-310 System User Manual Version 1.1

Figure 14 - Typical Cable Circuit Arrangement

5.1.1 First-Stage Cable Path Description

Motor shafts drive each 1

-stage through a special split pinion. All four motor split pinions are

identical except for length. The motor pinion parts are called the inner motor pinion (with

grooves for cable guidance) and the outer motor pinion (no grooves). The outer motor pinion

can rotate relative to the inner pinion via the tensioner to add pre-tension to a cable circuit.

Each motor outer pinion has a single termination at its end. Each motor inner pinion has a pair

of terminations at its root (only one termination is used on the inner pinion). When a first-stage

cable is attached to one of these inner pinion terminations, it is wound first one-half turn

through the second (unused) termination and then with a tight right-handed pitch over the

pinion surface. The cable is wound neatly into the guide grooves.

The other end of each first-stage cable then spans across to the pulley section of a pulley/pinion

with an open wrap such that the motor pinion and the pulley/pinion rotate in the same direction.

For the first three motor drives, the cable is then wound with a right-handed pitch, which

matches the tight pitch angle of the cable wound on the motor pinion. After several winds, the

cable's brass lug-termination is attached to the termination slot at one end of the pulley. The

termination slot at the other end of the pulley remains unused.