08/10/2025 By CNCBUL UK EDITOR Off

Technical Evaluation Guide: How to Identify a Quality Used, Secondhand, Pre-Owned, Surplus Mazak PFH-5800 CNC Full 4th axis Horizontal Machining Center with 6 Station Pallatech System made in Japan

1) Machine Overview & Benchmark Specs

Before on-site inspection, gather published specs for your specific unit so you can compare actual vs spec. This gives you baseline expectations. Example specs for PFH-5800 include:

X / Y / Z travels: ≈ 730 × 730 × 740 mm
Spindle: 12,000 rpm, BT/CAT-40 or similar taper, ~22 kW drive power
Pallet size: ≈ 500 × 500 mm (for each pallet)
Pallet load capacity: ~700 kg
4th axis (B-axis / pallet indexing) with 0.001° indexing accuracy (non-interpolating)
Tool changer capacity: e.g. 80 pockets
Through-spindle coolant (70 bar or low pressure) option
Control: Mazatrol 640M (or Fusion 640M)
Weight / footprint: ~11,600–13,400 kg, large floor footprint

Knowing these spec values sets your acceptance thresholds.

2) Pre-Inspection Document Request

Ask the seller to provide:

Machine’s specification / build sheet (factors like pallet system, B-axis rating, ATC type)
Serial number, build year, and past ownership
Service / maintenance logs (spindle rebuilds, axis overhauls, lubrication)
Geometry / calibration / laser test reports
Control parameter backups, axis compensation tables, B-axis calibration data
Electrical / hydraulic / pneumatic schematics
Tooling / pallet system parts list

These documents help you set pass/fail benchmarks before going on site.

3) Visual & Static Inspection (Power Off)

When the machine is de-energized:

Frame & Base: Check castings, weld repairs, cracked joints, internal weld lines, signs of overload or collision damage.
Pallet Stations (Palletech): Look for wear or damage on pallets, indexing pins, pallet support rails, lock/unlock mechanisms.
Pallet surfaces: Table flatness, no scoring or heavy marks; check contact surfaces for matching tolerances.
Guideway / Ways Covers: Check for gouges, corrosion, lubricant crusting, chip damage, way cover condition.
Spindle Nose / Taper: Inspect for damage, corrosion, scoring.
ATC / Tool Magazine: Check magazine arms, tool grippers, pocket wear, indexing for play.
Coolant / Through-spindle Plumbing: Check internal coolant lines, seals, O-rings, unions for leaks or damage.
Electrical Cabinet / Wiring: Open and inspect; look for overheating, dusty accumulation, rodent damage, burnt wiring.
Hydraulic / Pneumatic Lines: Inspect hoses, pressure lines, valves, accumulators for leaks or deterioration.
Cabinet Doors / Safety Guards / Covers: Hinges, interlock switches, door alignment, condition.

4) Power-On & Functional Tests

With power supplied (and safety procedures enabled), perform:

Warm-up / Initialization: Run axis motion for 20–30 min to stabilize temperature.
Homing / Zero Return: Check repeatability of home positions.
Axis motion test (X, Y, Z): Jog at 25 %, 50 %, 100 % feed/rapid rates; listen for unusual sound, chatter, or binding.
Pallet / B-Axis Indexing: Index several pallets; check locking repeatability, speed, and no mis-index.
Tool Change Cycles: Run ATC cycles multiple times (20+); test pick / drop / tool change reliability.
Spindle Speed Sweep: Ramp from low to max rpm and back while monitoring vibration, noise, temperature ramp.
Through-Spindle Coolant Flow: Engage coolant, check pressure, flow consistency, no leaks.
Control / CNC Alarms: Review alarm log; induce mild error conditions and verify error detection functions.
Pallet Exchange Test (if automatic): Exercise pallet change sequence; check cart motion, shuttle alignment, rails.

5) Accuracy & Motion Verification

These are the most critical tests for geometry and performance:

Laser Interferometer / Renishaw measurement: Run positioning and straightness tests in X, Y, Z axes. For example, measure linear positioning error over full stroke segments.
Repeatability: Back-and-forth motion (e.g. ±0.1 mm), measure deviation over multiple cycles.
Squareness / Orthogonality (X–Y, Y–Z, X–Z): Using a precision square or laser collimator.
Circular / Arc Interpolation Test: In 4th-axis mode, command a circular or angular contour and measure deviation from nominal.
Corner Accuracy / Tool Center Offsets: Mill a test block with multiple faces and measure perpendicular faces, step transitions, and alignment.
Pallet-to-Pallet Repeatability: Mount same part at different pallet positions and compare measured dimensions.
Thermal Drift Study: Run prolonged machining (1–2 hours) at moderate load; periodically measure reference features to see drift.
Backlash / Reversal Error: Jog reversal at small increments (e.g., ±0.01 mm) and inspect error magnitude.

6) B-Axis / 4th-Axis (“Pallet / Palletech Index”) Mechanics Check

Index Accuracy: Verify the B-axis (or pallet indexing) can index to its positions with minimal error—compare index command vs actual.
Locking / Clamping Force: Check the hydraulic / mechanical clamp on the B-axis or pallet indexing mechanism holds firmly with no slippage.
Torque / Drive Motor Loading: During indexing, monitor motor current or torque load. Spike or overload may indicate binding or misalignment.
Encoder / Feedback System: Verify the encoder or feedback device is functioning properly and no lost counts under motion.
Tilt / Interpolation (if used): If the 4th axis is used in tilt or rotational mode, test small angular movements; check hysteresis, tilt drift, or backlash.

7) Spindle, Tooling & Wear Checks

Spindle Runout / Vibration: Using a test bar, measure radial runout at nose. Use vibration analyzer to look for bearing frequencies.
Temperature Rise: Run at a mid-high rpm for 30 min; measure spindle temperature rise.
Drawbar / Tool Retention Force: If tool change is hydraulic or mechanical, measure retention force with pull gauge.
Taper Surface Inspection: Blue test or dye test to check contact area.
Tool Seating / Eccentricity: Use calibration tools to check that tools seat correctly in the spindle.
Tool Change Accuracy: Check that tool offsets and repeat pick-up offsets are consistent.

8) Coolant, Chip & Lubrication System Tests

Coolant System: Check pump pressure, flow rate, cleanliness, leaks, shut-off valves, filtration system.
Chip Conveyor / Chip Handling: Run conveyor, inspect rail wear, no jamming or loose links.
Lubrication / Way Oil Circulation: Confirm lube system is functional, supply to all axes, check for leaks or blockages.
Hydraulic / Pneumatic Attitudes: Check pressures, valve responses, accumulator charge states.
Tank / Filtration Units: Inspect filters, cleanliness (metal particles), leaks, ease of maintenance.

9) Common Wear Patterns & Failure Modes

Wear on pallet indexing rails or guides causing pallet misalignment.
Worn clamping surfaces on pallets leading to positional drift under load.
Turret / ATC wear, gripper inaccuracy.
Spindle bearing wear (noise or vibration).
Axis backlash creep or degraded servo performance.
Cooling & coolant leaks causing internal corrosion or washout of lubrication.
Control or drive failures—outdated electronics, failing capacitors, servo amplifier degradation.
Hydraulic leaks or valve sticking.
Encoder issues or lost-count errors in high-dynamic modes.

10) Required Documentation & Records

Ask for:

Factory build / configuration sheet
Geometry / calibration / laser / ballbar reports
Service / maintenance logs (spindle rebuilds, axis overhauls)
CNC / control parameter backups
Hydraulic / pneumatic schematics
Spare parts list (pallet system components, tool changer parts)
Manuals / operating instructions
Evidence of retrofits (if any)

11) Acceptance Criteria Summary (Benchmarks)

Here is a sample target sheet you could use to judge whether the unit is acceptable:

Parameter	Target / Tolerance	Notes
Positioning accuracy (X, Y, Z)	±0.005 mm over 300 mm	Depends on spec sheet
Reversal / backlash error	≤ 0.01 mm	Low is better
Repeatability	±0.003 mm	Over many cycles
Pallet indexing accuracy	≤ 0.005 mm	From commanded index
Spindle runout	≤ 0.005 mm	At nose
Thermal drift	≤ 5 µm over 1–2 hrs	Under load
Tool change repeatability	≤ 0.01 mm	For offset consistency
Coolant stability / pressure	Within spec range	No drop under load
Drive / servo current stability	No sudden spikes	Smooth trace
Noise / vibration at rpm	Minimal	Use analyzer