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OmniTurn G3 CNC: Spindle Starts in Only One Direction
Legacy Inverter Spindle Drive (TB1)

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This page addresses a condition where you can jog, but the spindle starts in only one direction, either M03 or M04, but not both.

Likely cause of this behavior is bad connection from MC2 card to Connect card, bad connection in MISC cable, or failed driver on MC2 card.

These instructions apply only to inverter drive on legacy spindle panel with TB1 terminal strip.


The instructions on this page assume you have performed initial tests here, and found that the spindle will start in one direction (M03 or M04), but not the other.


Open the Spindle Drive Cabinet

Measure Voltages on TB1

TB1 is the long terminal strip that runs down the left side of the electrical panel. Terminal 1 is the top terminal on the strip. (For reference, here is PDF of spindle cabinet components)

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