108797 Split Servo Board Layout

108797 Split Servo Schematic

3 Phase Plugging Resistor Connections

3-Phase Motor Wye-Delta Connection Instructions

Motor Connection Data

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42B Lot 20 thru 22 Back Gear Switch Replacement

Adjustment of Mechanical Plugging Switches

Many Lucas machines are equipped with Plugging Switches for rapidly stopping the Spindle Rotation. This is done for several reasons including more rapid cycling of the machine and increased personnel safety. The plugging adjustment is not particularly subject to wear and should not need periodic re-adjustment, however, in the event that your Plugging Switch needs to be re-adjusted, here is the correct process to follow:

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Allen Bradley Relay Contact Conversion

Allen Bradley Timer Relay Conversion

ER Conversion from Early Solid State Type Units

This listing describes the conversion of Lucas Machines equipped with older style 'ER' (Electronic Relay) speed sensing relays to a unit of a more modern design.

While the newer units are functionally equal to the older units and use many of the same component parts, the primary advantage gained by installing a new unit (instead of repairing the original) is in the machine tool reliability gained by replacing all of the 'aged' components at one time - rather than one piece at a time as they fail.

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ER Conversion from Radio Tube Type Units

This listing describes the conversion of Lucas Machines equipped with General Electric 'radio-tube-type' Electronic Speed Sensing Relays to a Lucas Precision printed circuit board.The older units are G.E. part number CR7511B11 'Voltage Sensitive Relay' (wired to G.E. Blueprint M-5119288) and are equipped with radio tubes, part numbers 6SN7GTB and GL2050.While radio tubes may still be purchased for repair of these units, several of the other parts that are used on this assembly are no longer available from any source.

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SCR Drive History & Support - for Customer Reference

SCR Drive Design History

The following is a historical narrative of the design progression of the Lucas SCR feed drive. It is intended to familiarize the reader with the various versions and revisions that were produced of the drive, and to aid in the selection of what newer type or revision of the drive to supply for replacement purposes.

Firing Module History (The main printed circuit board).

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Speed Shift Lever Switches


Spindle Rotation Direction Definition

Many times in Lucas literature, you will see reference made to the CW and CCW directions of Spindle Rotation. All other definitions notwithstanding, the CW (Clockwise) direction of Spindle Rotation is the direction the Spindle would be rotating to use a common twist drill mounted in the Spindle taper.


Lucas machines are designed to 'Shift-Jog' in a CW direction ONLY.

If your machine is 'jogging' in the opposite direction, you are much more susceptible to gear ratcheting and possible gear damage.

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Three-Phase Transformer Wiring Tips

Three-Phase Wiring Tip 1

Tube Type ER Relay


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