Here’s a detailed checklist of what to look for, test, and ask when evaluating a second-hand Okuma MB-5000H horizontal machining center. It’s a capable and complex machine; the better your inspection, the fewer surprises in maintenance, repair, or operability.

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Key Specs / What the MB-5000H Should Generally Offer

These are baseline performance/features you should verify versus what the seller claims:

• Axis travels: approximately 760 mm in X and Y, ~810 mm in Z.
• Spindle speed up to ~15,000 rpm for many models.
• Power & torque of spindle (watts or HP) appropriate for your cutting loads.
• Table/pallet size ~500×500 mm (≈ 20″×20″) or equivalent.
• Tool magazine / ATC capacity (varies by configuration).
• Coolant options: through-spindle coolant (TSC), high-pressure coolant, chip conveyor, flood or mist etc.
• Control system: e.g. OSP-P300, OSP-P300MA etc., with capability for thermal compensation, diagnostics etc.

Having the correct spec for your intended parts / materials is essential; underspec’d machines cost you time or cause quality issues.

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What to Inspect & Test Before Purchase

Here is a more detailed checklist—mechanical, electrical, precision, wear—that you should go through in person if possible.

1. Spindle & Spindle Head
   • Check for wear in spindle bearings: listen for noise/vibration at different rpms, ideally also under light cutting load.
   • Measure radial and axial run-out at spindle nose & taper.
   • If the machine has through-spindle coolant, test it: fluid flow, seal condition, pressure.
   • Inspect the taper or collet interface for wear or damage.
2. Axes, Guideways & Ball Screws
   • Fully travel in X, Y, Z axes; feel for smoothness, any sticking, binding.
   • Check backlash / slack in ball screws / feed axes (especially over longer distances).
   • Examine way covers, seals: damaged or missing covers allow chips or coolant to enter and damage guides.
   • Check lubrication system (automatic or manual): are oil pumps, grease points, filters working and clean.
3. Pallet / Table & Pallet Indexing (if equipped)
   • Check table flatness, T-slots condition, rigidity.
   • Indexing accuracy if pallets or rotary tables; locking mechanisms should hold firmly without slop.
   • Check spindle-to-table clearance (spindle nose to pallet, center heights) across travel.
4. Tool Magazine / Tool Change System
   • Verify the tool changer works reliably: tools load/unload cleanly, no mis-alignment.
   • Inspect magazine capacity and whether all slots/stations are usable.
   • Check tool holder condition: whether holders are worn, how well they seat.
   • Tool change timing: does it take too long, any delays.
5. Coolant / Chip Removal / Filtration
   • Check coolant tank: level, condition (rust, contamination, bacteria), pumps, hoses.
   • If high-pressure coolant or TSC: are pressure specs met, are seals good.
   • Chip conveyor, chip augers or removal system: are they working well; are there frequent blockages.
   • Guards, covers and ways to handle chip cleanup visible; observe how chips are directed or dumped.
6. Control System & Diagnostics
   • Boot the control (OSP etc.): check software version, display, buttons/controls.
   • Look at error/alarm history or logs: recurring errors or warnings may indicate wear or misalignment.
   • Check whether thermal compensation features are installed and functional (Okuma includes “Thermo Active Stabilizer” etc. in many models).
   • Check if diagnostics tools work (ball screw support bearings, feed axis diagnostics etc.).
7. Drive Motors, Servos, Feeds & Rapids
   • Test rapid travel vs cutting feed: whether it’s achieving claimed speeds.
   • Listen and watch for stalls, jerks, vibration under load.
   • Check motor condition (heating, unusual noises).
   • Inspect belts, pulleys (if belt-drive is part), gearboxes.
8. Wear Items & General Condition
   • Look for corrosion, rust, paint / protective coating condition. Areas around the spindle, tool changer, way covers etc.
   • Worn parts: way surfaces, ball screw threads, nuts, guide rails.
   • Condition of hydraulic components (if any), pumps, valves.
9. Parts / Tooling / Accessories
   • What is included with the machine: fixtures, probes, coolant nozzles, tooling, tool holders etc.
   • Availability of spares locally (bearings, seals, filters, electronic boards).
   • Manuals and documentation: wiring diagrams, maintenance manuals.
10. Safety and Guards
    • Emergency stop buttons; safety interlocks on doors / enclosures.
    • Guards around moving/potentially dangerous parts (tool change area, chip conveyor etc.).
    • Electrical safety: grounding, proper wiring, cable condition.
11. Operational Test / Sample Machining
    • Run a sample program that mimics the work you expect to do (material, size, complexity).
    • Inspect parts for finish, dimensions, tolerance.
    • See machine behaviour over time: does it drift when warm? Any changes in performance.
12. Installation / Facility Fit
    • Machine footprint, weight: can your floor support it; is there enough clearance.
    • Power supply: verify voltage, phase, amperage; is your facility able to supply what the machine needs.
    • Cooling, ventilation, chip removal, lighting, access for maintenance.

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Specific Known Issue Areas for MB-5000H & What to Ask About

These are issues that owners or reviews commonly report, or features whose failure has high cost:

• Checking for spindle vibration or heating at high RPMs; spindle bearings are wear-items and expensive.
• Thermal stability: the MB-5000H has features like “TAS-S” / “TAS-C” (Thermo Active Stabilizers) to help reduce thermal deformation; verify these features are working.
• Tool changer reliability: mis-feeds or magazine indexing problems can slow production or cause tool crashes.
• Through-spindle coolant (TSC) and high pressure coolant: seals tend to degrade; verify no leak, pressure maintained.
• Chips and coolant management: chip conveyors clogged, way covers damaged, coolant contamination.
• Accuracy of pallet indexing / rotary tables if present; locking of pallets; backlash etc.
• Diagnostics/maintenance history: ball screw support bearings or feed screw wear (as Okuma brochures note feed axis diagnostics).