Buying a used Mazak Integrex e650H II / 4000 (or a variant thereof) is a major investment. These multitasking CNC machines combine turning, milling, and multi-axis work, so there are many subsystems to validate. Below is a detailed checklist and pitfalls to watch out for when evaluating a candidate machine.

What “Integrex e650H II / 4000” suggests — baseline expectations & model features

Before inspection, you want to know what the machine should be capable of so you can detect wear, modifications, or underperformance. Some reference data for the Integrex e-series:

• Many published listings for Integrex E-650H show turning diameter ≈ 920 mm, turning length (distance between centers) ≈ 4,000 mm, spindle bore ~170 mm.
• Power and speed: typical main spindle up to ~ 1,600 rpm, with milling / live tooling axes capable of higher speeds (e.g. 10,000 rpm) in many configurations.
• Tool magazine / ATC capacities in used listings vary (e.g. 80, 120 position) depending on configuration.
• The “II” generation likely includes enhancements (control, rigidity, features) over earlier models.
• Because these machines combine turning + milling + multi-axis, there will be multiple motion axes (X, Y, Z, B, C), live tooling, tool changers, possibly subspindle, and various support systems (coolant, chip handling, guarding).

Thus, your inspection must cover turning systems, milling/live tool subsystems, multi-axis synchronization, control / electronics, and auxiliary systems.

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Inspection / Evaluation Checklist

Below is a comprehensive breakdown by subsystem of what to inspect, what to test, and what red flags to watch for.

Subsystem	Inspection & Tests	What to Watch Out / Risk Indicators
Frame, base & geometry	• Examine casting, pillars, bed, cross-support for cracks, weld repairs, distortions, signs of collisions. • Check alignment and straightness of major structural members (e.g. beam, columns). Use straightedges, laser alignment, etc. • Confirm machine is properly grounded, mounted, and level.	Structural damage or misalignment is very expensive to correct; even small twist or sag degrades accuracy in a big machine.
Guideways / linear axes (X, Y, Z, etc.)	• Jog each linear axis slowly over full travel; feel for binding, friction changes, “sticky spots.” • Reverse direction and check for backlash or hysteresis. • Use indicators or measuring equipment (laser, dial gauges) to test straightness, linear deviation, “steps” in motion. • Visually inspect the guide surfaces for scoring, pitting, embedded chips, rust, or corrosion.	Wear or damage in linear ways is a common wear point in large machines. If guides are severely worn, rebuilding or replacement is costly.
Ball screws / drives / couplings	• Move axes over varying speeds; listen / feel for noise, vibration, roughness. • Check for axial or radial play in screw-nut assemblies. • Inspect screw threads and nut interface for wear, pitting, contamination. • Examine couplings between motors and screws for looseness or misalignment.	Worn screws / nuts degrade positioning accuracy and repeatability. Replacement is expensive.
Main spindle & turning system	• Run the spindle at different speeds (low, med, high); listen for noise, vibration, growl, hums. • Mount a test bar or collet + indicator to measure radial and axial runout. • Let the spindle run for a while to warm up; use a thermometer or temperature sensor to check for overheating. • Inspect the spindle nose, taper, seating surfaces for wear, burrs, corrosion. • If subspindle or secondary turning spindle exists, test its performance, alignment, clamping.	Spindle bearings are one of the most expensive components. Excessive runout, noise, or overheating often indicates nearing end of life or improper maintenance.
Milling / live tooling / multi-axis subsystems	• Test live tooling (milling/drilling) under load: check for runout, vibration, stability, power delivery. • Cycle B / C axes through range of motion, check for smoothness, backlash, repeatability. • Execute combined motion (simultaneous turning + milling) to test path interpolation, synchronization, dynamic behavior. • Inspect drive motors, gearboxes, coupling, belt / beltless transmissions of these axes.	Live tooling and multi-axis synchronization are complex and high-stress. Faults lead to poor surface finish, crashes, or in-out-of-spec machining.
Tool changer / magazine / tool handling	• Cycle the tool changer many times; check for misindex, collisions, delays, failures to clamp / release. • Inspect the magazine rails, sensors, grippers, drive motors, sensors, switches. • Test for reliability under continuous cycling.	Tool changer failure is a major downtime cause. Mechanisms may be hard to repair, especially custom robotic or long-bar handling options.
Control system & electronics	• Power on and watch startup sequence: note any error codes, missing I/O modules, warnings. • Cycle axes, tool changes, interpolated motion; check for smoothness, jumps, errors. • Inspect control / CNC cabinet: wiring harnesses, fans, heat sinks, discoloration, burnt traces, dust, corrosion. • Check encoder feedback, sensor wiring, shielding, connector integrity. • Verify that parameter backups, configuration files, compensation tables exist and can be restored. • Test motion commands, path simulation, macro sequences.	Control electronics are as critical as mechanics. Missing, failed, or corrupted modules or software often kill a used machine’s utility.
Cooling / lubrication / fluid systems	• Test coolant pumps, pressure, flow, hoses, nozzles, filters, plumbing. • Inspect coolant tank / reservoir: sludge, metal chips, contamination, erosion. • Check lubrication systems for axes, turrets, spindles — verify fluid delivery, absence of blockages. • Look for leaks (hose, seal, piping), signs of wear in wet zones, corrosion in coolant paths.	Poor fluid systems accelerate wear, cause thermal instabilities, lead to failures in bearings, guides, tool changers, etc.
Chip management, guarding & sealing	• Inspect chip conveyors, chip flushing, coolant return paths, guarding covers. • Check that bellows, covers, wipers, seals are present and intact — they protect critical moving parts from chips and coolant. • Look for chip intrusion or embedded debris on guide surfaces or inside mechanical cavities.	Chips and abrasive debris inside mechanisms cause scoring, wear, misalignment over time. Missing guards or poor sealing is a red flag.
Thermal drift & stability	• Run the machine under load for an extended period (30–60 min or more). • Re-measure positions, test parts, or indicator readings before/after run to detect drift. • Observe whether components, axes, or the structure heat unevenly, causing dimensional changes.	Even well-maintained machines may drift. Large drift is symptomatic of design, wear, or cooling/thermal issues.
Test part & production trial	• Request or run a test part (one similar to your intended work). • Monitor surface finish, dimensional accuracy, multi-axis motion, tool changes, cycle time. • Run multiple cycles to check repeatability, stability, consistency. • Vary speeds / feeds to stress the machine across its envelope.	Seeing how the machine behaves under real work is the best litmus test. Hidden flaws often reveal themselves here.
Maintenance history & usage profile	• Ask for the year of manufacture, serial number, runtime hours (if logged), spindle hours, cycle counts. • Request maintenance logs: repairs, replaced parts (bearings, guides, screws, electronics), crash history, alignments. • Ask about the working environment (clean, dry, temperature-controlled vs dusty, humid, coolant-laden). • Ask whether any retrofits or upgrades were performed, and whether documentation exists.	A good documented history reduces risk; unknown or neglected history is a red flag.
Parts, support & documentation	• Check whether Mazak (or authorized distributors) still support that Integrex model and whether spare parts (spindles, drives, encoders, turrets, electronics) are available. • Ensure the seller gives you maintenance manuals, electrical / wiring diagrams, spare parts catalogs, control software / parameter backups, calibration data. • Ask about any spare modules, control cards, wiring spares, or consumables included.	Without parts and support, downtime or unrecoverable failure becomes a major cost.
Shop & infrastructure compatibility	• Confirm your power supply (voltage, phases, current) meets the machine’s requirements. • Ensure proper grounding, stable electrical service, low noise. • The floor / foundation must be rigid, level, and able to support the machine’s mass without deflection. • Space clearance: ensure you can access all sides, perform maintenance, tool changes, removal of large parts. • Chip / coolant drainage, filtration, wash-down and ventilation must be adequate. • Safety: emergency stops, guards, interlocks must meet your local regulations.	Even a perfect machine fails if installed improperly or in an unsuitable environment.

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Common “Red Flags” / Deal Breakers

Here are conditions or defects that should make you walk away (unless the price is extremely low and you plan a major rebuild):

• Spindle with severe bearing noise, excessive runout, or overheating
• Axes with binding, “stickiness,” or inconsistent friction over travel
• Linear guide or slide surfaces with deep scores, gouges, embedded chips
• Tool changer / magazine failures, repeated misindexing, collisions
• Control / electronics modules missing, burned, corroded, or unresponsive
• No parameter / software backup, or corrupt configuration files
• Missing or severely damaged guarding, seals, wipers, or bellows (leading to chip ingress)
• Poor or missing coolant / lubrication systems, leaks, contamination
• Structural damage (cracks, weld patches, distortions) to bed, bridge, supports
• No service or spare parts support for that model in your region
• The seller refusing full testing or hiding the machine’s interior or subsystems
• Environmental damage (rust, corrosion, moisture ingress) that has affected internal components

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Price, negotiation & risk mitigation tips

• Estimate the cost of likely refurbishments (guide regrinding / replacement, spindle overhaul, electronics repair) and discount accordingly.
• Insist on a test / acceptance period: allow yourself to run test jobs after installation before finalizing.
• Demand inclusion of documentation, software backups, spare parts, control cards if the seller holds them.
• Bring a Mazak / multi-axis machining / metrology expert with you to help test and validate.
• Include transport, installation, alignment, leveling, calibration costs in your overall budget.
• If possible, tie part of the payment to performance (i.e. “once machine consistently holds ±X tolerances, final payment released”).
• Ask for references from prior buyers of the same model to learn about typical failure modes or weak points.