Pratt & Whitney Wolverine Retrofit

This is a Centroid M400 retrofit to a heavy vertical mill from around 1981. The retrofit was completed in October 2006.

The machine is a large bed-type mill with a 40HP spindle motor driving three parallel spindles.

The Y axis servo moves the entire machine column forward and back.

This is the control cabinet. Yaskawa servo drives are at the top and left; the Square D / Telemecanique spindle drive is center right; and the Centroid PLC unit is lower left.

The cabinet is not as tidy as I would like. If I had it to do over again, I would move the Z servo brake resistor unit (the black device at upper left) outside on the right; line up the three servo packs across the top; move the spindle drive down a few inches; and use the gained space to add horizontal wire ducts and tidy up the PLC wiring. I would also repaint the subpanels.

UPDATE: in July-August 2007, I did have it to do over again, on a Pratt & Whitney lathe for the same customer. See PWStarTurn.htm for an illustration of how this cabinet should be done (admittedly with the benefit of only two axes, and the spindle drive mounted elsewhere).

This is the magnetics cabinet, back-to-back with the control cabinet. There were originally 36 control relays in the lower section. I kept six to convert AC input signals and switch large DC coil loads; all the rest I replaced with PLC logic.

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