TACHO DRIVE GEARBOX (COMMANDO) 2:1 REVERSING, DRIVES 4:1 INSTRUMENTS

WHEN FITTING NEW DRIVE CABLES ALWAYS CHECK CAREFULLY THAT THE INNER CABLE FULLY ENTERS THE INSTRUMENT WITHOUT ANY FORCE BEING REQUIRED. IT IS BEST TO FIT THE CABLE TO THE SPEEDOMETER GEARBOX OR TACHO DRIVE FIRST.

THE AMOUNT OF INNER CABLE AND PARTICULAR INSTRUMENT WILL ACCEPT IS SOMEWHAT VARIABLE BUT ANY CHRONO SHOULD ACCEPT AT LEAST 3/8" AND ANY MAGNETIC 1/2" MEASURING FROM THE END OF THE ALLOY FERRULE ON THE INNER CABLE.

ANY BURRS OR FRAYS CAUSING TIGHTNESS SHOULD BE REMOVED, AS WELL AS EXCESSIVE LENGTH. ALTHOUGH IF THE DRIVE COMPONENT WILL ACCEPT THE EXTRA LENGTH THE ALLOY FERRULE ON THE INNER CABLE CAN SOMETIMES BE MOVED ALONG SLIGHTLY.

TURNING TO A DIFFERENT PROBLEM, OCCASIONALLY A SPEEDOMETER GEARBOX CAN REFUSE TO ROTATE THE INNER CABLE DUE TO LACK OF CABLE ENGAGEMENT, WEAR ON THE CABLE OR A POORLY FORMED SQUARE IN THE GEARBOX OR ON THE CABLE. THIS CAN SOMETIMES BE RECTIFIED BY CLEANING THE INNER CABLE AND CAREFULLY WRAPPING WITH TIN FOIL.

PLEASE NOT THAT THESE COMMENTS/DIMENSIONS APPLY TO SMITHS EQUIPMENT AND MAY OR MAY NOT BE RELEVANT TO OTHER MANUFACTURERS.