Buying a used DMG MORI ecoMill 70 (5-axis vertical machining center) is a major investment. You need to verify mechanical integrity, control/electronics health, accuracy, and serviceability. Below is a detailed checklist and pitfalls to watch for.

Reference specs / baseline to compare with

Before inspection, get or confirm the nominal specifications so you know what “good performance” should look like. Some published specs for the ecoMill 70:

Parameter	Typical / published value
X travel	~ 750 mm
Y travel	~ 600 mm
Z travel	~ 520 mm
Tool magazine	~ 32-position, SK40 or ISO 40 style
Spindle speed	Up to 12,000 rpm
Table / swivel / axes	B axis −10° to +95°, C axis 360°
Table / clamping area	~ 800 × 620 mm, load ~ 350 kg
Rapid traverse (linear axes)	~ 24 m/min
Control options	Siemens 840D, Heidenhain TNC 620

Use these as benchmarks during inspection: if the machine falls far short, it may indicate wear, damage, or mis-adjustment.

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Detailed inspection & evaluation checklist

Here’s a systematic breakdown of subsystems and tests you should perform (or demand) when evaluating such a machine.

1. Structural / frame / geometric integrity

• Base, casting, frame
    – Examine base, cast iron structures, frame joints for cracks, weld repairs, distortions, or evidence of past collisions.
    – Check for signs of aging, fatigue, or distortion—especially in heavy load zones.
    – Verify that the machine is level and not twisted or bowed in its installed position.
• Columns, gantry, B/C axis supports
    – Check the rigidity and alignment of columns, overhead cross-members, gantry or support bridges.
    – Ensure the B/C axis supports, swivel arms, or rotary parts have not been bent or stressed.
    – Look for shim additions, backing plates, or structural patches that might indicate prior misalignment repairs.
• Guideway alignment / straightness
    – Use straightedges, precision bars, or preferably a laser interferometer to check linear guide alignment across the full range.
    – Inspect guide surfaces for wear, scoring, pitting, or embedded chips / debris.
    – Move axes slowly and feel for “steps,” binding zones, or nonuniform resistance.

2. Linear motion / axes / ball screws / feed mechanisms

• Ball screws & nuts / coupling / drive train
    – Check for backlash, play, or slop in each axis (X, Y, Z, B, C). Reverse direction and see how well it reverses without delay or overshoot.
    – Inspect screw threads at both ends and at nut interface for wear, damage, pitting, or rust.
    – Check couplings, alignment between motors and screws.
    – Listen / feel for uneven motion, grinding, or vibration when moving.
• Linear guide / slide condition
    – Manually or under control, travel full strokes and look for smoothness vs jerkiness, “sticking spots,” or zones where resistance changes.
    – Check for wear marks, corrosion, and signs that chips have scratched or gouged surfaces.
• Axis limits, homing, end stops
    – Test homing routines, limit switch behavior, and software travel limits.
    – Move to near travel extremes and check for interference, mechanical stops, or axis “ghost motion.”

3. Spindle, rotary axes & 5-axis mechanisms

• Spindle & bearings
    – Run the spindle at low, medium, and high speeds. Listen for noise, vibration, or roughness.
    – Mount a test bar or precision collet and measure radial and axial runout (taper quality).
    – After some runtime, measure spindle housing temperature—excess heat suggests bearing wear.
    – Inspect the spindle taper, nose, collet interfaces for wear, chips, corrosion.
    – If the machine uses direct drive or high-speed designs, check for evidence of surge / torque issues.
• Rotary / swivel / B & C axes
    – Command rotation (B and C axes) through full range, at different speeds. Watch for jerks, resonance, backlash, or drift.
    – Test precision of stops / indexing: rotate to a position, move away, return, measure deviation.
    – Under simultaneous motion (e.g. combined linear + rotary), observe dynamic behavior (e.g. vibration, coupling effects).
    – Inspect bearings, gearboxes, coupling (worm, harmonic, direct-drive, etc.) for play or wear.
• Tool orientation / head / kinematics
    – If the machine has a moving head or tilting head, test that mechanism—as it adds complexity and failure modes.
    – Check wiring, cabling, seals, and mechanical joint integrity in those moving parts.

4. Control, electronics, software & cabling

• Power-up / boot / diagnostics
    – Watch the machine boot. Note any error codes, missing modules, failed I/O, warnings, or discrepancies.
    – Access diagnostics, I/O status screens, alarm logs.
    – Inspect control cabinet: fans, heatsinks, wiring quality, signs of overheating, dust accumulation, or corrosion.
• Servo drives, motors, feedback / encoders
    – Inspect drive modules for signs of stress (heat, discoloration, loose connectors).
    – Run axes and check motor noise, hum, or vibration.
    – Inspect encoder cables and connectors: shielded, properly routed, no strain or damage.
    – During motion, check for feedback signal errors or dropouts.
• Software / parameter integrity
    – Ask for a backup of all parameters / settings, calibration / compensation tables. Verify they are intact and restorable.
    – Check for firmware version, custom patches, or “nonstandard” modifications.
    – Test parameter editing, save / restore behavior, and see if compensation settings (thermal compensation, axis linearization, backlash correction) are functional.
• Homing, reference, interpolation, tool cycles
    – Run typical 5-axis motion programs (linear + B + C) to verify smooth interpolation and motion control.
    – Test tool change sequences, look for collisions, delays, mis-indexing.
    – Test feedrate override, lookahead, acceleration/deceleration behaviors.
• Safety, interlocks, limits
    – Test e-stop, guard door interlocks, axis limits, motion disable upon guard open.
    – Try opening covers / doors (in a safe mode) to see if machine halts.

5. Accuracy, calibration & metrology tests

• Geometric validation / volumetric accuracy
    – Use laser interferometry, ballbar, or precision measurement devices to test straightness, angular errors, linear axis accuracy.
    – For a 5-axis machine, test volumetric accuracy (i.e. how positional error accumulates in combined axes) — often the real test of machine quality.
    – Move to a given 3D point, retract, return, and measure return accuracy.
• Thermal drift / repeatability under load
    – Run the machine for a period (under moderate load) and re-check positions to see if error grows or drifts.
    – Check for warm-up distortions or axis drift over time.
• Production / “real” part trial
    – Run a sample part (representative of your intended work) through full 5-axis motions. Inspect final dimensions, surface finish, alignment across faces.
    – Repeat multiple runs to check consistency.

6. Tooling, tool changer, spindle interface & consumables

• Tool changer / magazine
    – Cycle tool changes many times. Look for failures, mis-indexing, slow operations, sensor problems, collisions.
    – Inspect magazine rail mechanics, locks, sensors, slides for wear or play.
• Tool holder integrity / taper runout
    – Mount test tool holders, measure runout, check repeatability of tool-to-tool mounting.
    – Inspect the taper faces, clamp surfaces, retention systems for wear or damage.
• Tool cooling / through-spindle coolant / coolant plumbing
    – If the machine supports through-spindle coolant or side-coolant for tools, test the coolant paths (pressure, leaks, blockages).
    – Inspect plumbing, seals, hoses.

7. Maintenance history, wear & usage profile

• Age, hours, usage counts
    – Ask for power-on hours, spindle hours, cycle counts, usage logs.
    – Compare with how intensively you plan to use the machine.
• Maintenance / repair logs
    – What components have been replaced or serviced (bearings, encoders, linear guides, drives, control modules)?
    – Any crash events, collisions, overloads — how they were repaired.
    – Environment of operation (dust, humidity, temperature, coolant practices) and maintenance discipline (cleaning, lubrication).
• Modifications / retrofits
    – Be cautious of custom modifications, unapproved retrofits, or “band-aid” repairs. These may signal hidden issues.

8. Spare parts, support, and ecosystem

• Parts availability
    – Are original DMG MORI parts still available for the ecoMill 70 line (drives, spindles, encoders, axes, control modules)?
    – Are there local or regional suppliers or service houses capable of supporting this machine?
• Documentation / manuals / backups
    – Make sure you receive operator manuals, maintenance manuals, electrical schematics, wiring diagrams, calibration & compensation tables.
    – Ensure parameter backups, control customizations, motion profiles are included.
• Support & service network
    – Is there a DMG MORI service presence in your country (Turkey) or Europe?
    – Check how long lead times are for critical parts and whether remanufactured spares are viable.

9. Shop readiness & infrastructure compatibility

• Electrical / power supply
    – Confirm that your shop can supply the correct voltage, phase, current (amps) with stable supply.
    – Consider adding power conditioning / surge protection if needed.
• Foundation, leveling, and rigidity
    – The machine must sit on a solid, rigid, flat floor. Vibrations or flex in foundation degrade accuracy.
    – Check anchor points, bolt holes, leveling arrangements.
• Space / clearance / crane & rigging
    – Ensure adequate clearance around the machine for maintenance, tool changes, access to axes, overhead lifting / crane for parts & spindle removal.
    – Assess how the machine will be moved in/out and whether your facility can support it.
• Cooling, ventilation, heat management
    – Drive electronics, control cabinets, and spindle cooling generate heat. The workshop must ventilate or cool appropriately.
    – Chip / coolant management systems (filtration, conveyors, sump, coolant chiller) must be in place or do-able.
• Safety / guarding / compliance
    – Guards, interlocks, light curtains, emergency stops must meet local safety regulations.
    – The machine should safely disable motion when doors or guards are open.

10. Pricing, negotiation & risk mitigation

• Estimate the cost of likely repairs (bearing replacements, rework of axes, control modules, calibration) and deduct from the asking price.
• Require a test / acceptance clause so that you can verify performance after installation with your own test parts.
• Demand inclusion of spare parts, tooling, backup modules, parameter backups.
• Bring along a 5-axis machining / metrology expert for inspection if possible.
• Include shipping, installation, alignment, calibration, and acceptance costs in your total investment budget.
• Ask for a performance guarantee, limited warranty, or liability clause for hidden defects.
• Check references from prior buyers of the same model and ask about common failure modes or quirks.

11. Red flags / deal-killing defects

If you discover many of the following, the machine’s risk may be too high unless priced deeply discounted:

• Cracked or welded repairs in critical structures (frame, columns, gantry)
• Severe wear or scoring on guideways or linear axes
• Excessive backlash, slop, or non-repeatable motion in axes
• Spindle bearing noise, high runout, heating, taper damage
• Rotary/trunnion axes that bind, jitter, or have large indexing errors
• Drives or electronics with repeated faults, missing modules, or unreliable performance
• Control parameter corruption, missing backups, or incompatible software
• Seller refusing full test runs or denying access to run programs
• No documentation, wiring diagrams, parts catalogs, or calibration data
• No support network or severely delayed parts supply
• Environmental damage (rust, moisture, corrosion inside electrical enclosures)
• Mismatch between claimed vs actual motion or performance
• Safety systems not working or bypassed