Okuma GI Series Repair & Support

GI Series Models & Specifications

The range spans a compact, fast-cycle production grinder through a larger, multi-spindle-capable platform.

Which OSP Control Does the GI Series Use?

Current GI Series machines run OSP-P300GA, a grinder-specific control variant built around IGAP+ conversational programming for easier setup. Older in-service machines commonly run legacy controls including OSP5000LG, OSP-U10G or OSP-U20G, which we regularly service given how long these grinders remain in production use.

Because multi-spindle configurations (2WS/4WS) coordinate spindle selection through this same control, a fault affecting only one spindle in a multi-spindle setup — while the others continue working normally — points toward that specific spindle’s drive or the control’s spindle-selection logic rather than a general control fault.

Common GI Series Faults We Repair

The GI Series’ high-frequency spindles and multi-spindle configurations create a fault profile distinct from an O.D. grinder or machining center.

High-frequency wheel spindle faults

At speeds up to 150,000 RPM, spindle faults on this platform often present very differently from a conventional machining spindle — overheat protection trips and bearing wear both progress faster at these speeds, so we bench-test the specific spindle unit rather than assuming a standard spindle fault pattern applies.

Multi-spindle configuration faults (2WS/4WS)

On machines with two or four wheel spindles, identifying which specific spindle is failing — rather than assuming a general fault — is the first step in diagnosis, since each spindle in a multi-spindle configuration typically has its own drive electronics.

Hydrostatic guideway faults

Because the cross-slide and table both ride on a film of oil rather than mechanical bearings, faults here often trace to the hydraulic lube system supplying that oil film rather than a worn mechanical guideway — a genuinely different diagnostic approach than a conventional linear guide.

Workhead swivel and chuck faults

Workhead swivel-angle faults typically trace to the swivel mechanism’s own position feedback rather than the main spindle drive, and are worth checking separately from chuck-clamping issues.

Display and operator panel faults

Standard OSP-P300GA and legacy control display and panel faults follow the same repair pattern as other Okuma machines.

Given the spindle configuration variety on this platform, we confirm the exact wheel spindle setup and control generation before isolating any failing component. See our fault analysis and testing & diagnostics services for more on our approach.

Where We Support GI Series Machines

CNC Elektronik is based in Germany, where automotive-component manufacturers rely on the GI Series for tight-tolerance bore grinding in high-volume production.

We’ve also supported GI Series repair work in the Czech Republic and Slovakia, where automotive-parts manufacturing relies heavily on precision internal grinding, as well as in Brazil, where growing automotive-component production is adopting similar high-speed internal grinding platforms. The process is the same regardless of distance: confirm the exact spindle configuration and control generation, isolate the failing component, and verify grinding accuracy before the machine returns to production.

See our Countries We Serve page for our full regional coverage across Europe, the Americas, and parts of Asia and the Middle East.

Frequently Asked Questions