Lucas 441B-72 Horizontal Boring Mill Retrofit

This is a Centroid M39 retrofit to a 72" x 60" horizontal boring mill from pre-1980. The retrofit was completed in March 2013.


The machine is a 3-axis, 25HP horizontal boring mill with ca. 72" X and 60" Y axis travels, plus ca. 24" Z in the table top (platen). Bar advance is manual or spindle-driven.

The machine had previously been retrofitted, around 1980, with an Allen-Bradley 7360. By the time my customer purchased the machine in 2013, it was ready for an update.

The headstock has three spindle speed ranges: a direct-drive clutch, plus two back gears.


This is the new control cabinet. Yaskawa Sigma V servo drives are at the top left, with their regenerative braking units facing them on the left door. Centroid MPU11, GPIO4D and PLCADD1616 control boards are below the drives. The drives are controlled via Centroid OpticDirect interface units, mounted to the side of each drive, receiving commands from the MPU11 board via optical fibers.

The Yaskawa A1000 spindle drive is at the top right. The spindle braking resistor unit is mounted externally, as it is a more significant heat source than the servo resistors.

Because this is an M39-style control, the PC assembly is inside the cabinet, in this case mounted on the left door.

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Copyright © 2016 Marc Leonard
Last updated 17-Nov-2016 MBL