This is a Centroid M400 retrofit to a 72" x 72" horizontal boring mill from around 1982. The retrofit was completed in December 2009.
The machine is a 4-axis, 20HP horizontal boring mill with 72" X and Y axis travels, 24" Z (bar) and 18" W (platen).
The original control was an Allen-Bradley 7300. By early 2009 it had reached the end of its useful life.
Spindle speed was controlled through a 16-speed transmission, with
hydraulic shifters. For the Centroid retrofit we installed a 20HP
variable-frequency AC drive and motor, with M function support for
shifting among four of the original 16 gear ranges. This provides
fully-programmable spindle speeds, while retaining the torque advantage
of the geared head. In the lowest range, the motor-to-spindle reduction
is nearly 70:1!
This is the new control cabinet, containing the servo drives, spindle drive, PLC unit, magnetics and supporting components. It is less than half the size of the original control cabinet set, and sits closer to the column.
With this cabinet and a smaller spindle oil cooler, the machine's footprint
has been significantly reduced.
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Copyright © 2011 Marc Leonard
Last updated 02-Nov-2011 MBL