If you’re considering buying a pre-owned Hauser S40-600 (or similar) CNC jig / hole-grinding / coordinate-hole grinding machine, especially a 6-axis model, there are many facets to check carefully. These machines are precision tools; mistakes or neglect can lead to huge costs (repairs, scrap, lost uptime). Below are professional / expert tips: what to look for, what to test, what to beware of, and red flags. I also include model-specific data for the Hauser S40 family to help you benchmark.

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Key Specifications & What They Imply

First, know what the “standard” or “typical” specs are for the Hauser S40-series, especially the “S40 / S40-CNC / S40-600 / S40-DR” etc., so you have a baseline for what to expect. Some listings give the following:

Spec	Typical Value / Range
Table size (L × W)	~ 770 × 630 mm
Workpiece-table load capacity	~ 500 kg
Travel (axes) X / Y / Z / W etc.	X (longitudinal) ~ 650 mm; Y (cross) ~ 450 mm; Crossrail / W (vertical slide) ~ 500 mm; Z or spindle vertical travel ~ 130-140 mm in some versions.
Spindle speed	Standard grinding spindle speed ~ 30,000 rpm; optional / turbine / Hi-cut versions go higher (up to ~80,000 or even 100-160,000 rpm in some DR/turbine modes) depending on head type.
Distance between columns / clearance	~ 750 mm between the columns; distance from spindle axis to table in many units ~ 0-600 mm.
Controller / CNC model	Hauser S40-CNC versions often have Fanuc controls, e.g. Fanuc 210 IS-M.

Knowing these helps you catch when a machine is under-spec’d (or claims spec but doesn’t deliver).

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What to Inspect & Test (Physical, Mechanical, Electrical & Controls)

Here are detailed checks. Think of bringing a machinist or toolroom specialist with you.

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1. Documentation & History

• Ask for full service history: when spindle bearings were replaced, when slides / crossrails were serviced, when any overhauls or calibrations were done.
• Running / working hours: both “power on time” and “cutting / grinding time” if available. These tell you wear exposure.
• Any major incidents: crashes, overloads, collisions, past damage to bed, column, spindle head.
• Records of previous accuracy tests, alignment / calibration logs.
• Manuals, electrical schematics, parts lists, write-ups of what was retrofitted, modified, or upgraded.

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2. Mechanical / Structural Condition

• Guideways / Crossrails / Column: inspect for wear, scoring, rust, pitting. The crossrail (vertical slide), column faces, table ways—all matter. Excessive wear here reduces accuracy and costs heavily to repair.
• Spindle condition: Run-out at spindle nose, taper, check noise/vibration. Also check condition of the spindle bearings: any play, heat, roughness. If spindle is a high-rpm or turbine type, check that it still meets its high-speed tolerances.
• Table: flatness, alignment, surface condition; T-slots: are they worn, damaged, correct spacing; workpiece fixture surfaces.
• Travel moves: move each axis (X, Y, Z, W, U, etc.) through full travel; listen/feel for sticking, binding, backlash, jerky motion.
• Load handling: since these machines are designed for heavy workpiece loads (500-800 kg in some variants), test with a heavy fixture / test load if possible. Deformation under weight can reveal alignment or structural issues.
• Wear of spindles / chucking / fixture elements: tool holding / mandrels, fixtures for jig holes. If these are worn, precision suffers.

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3. Electrical, Controls & Software

• Control system: brand/version, firmware, whether parts/support are still available. For example, Fanuc 210 IS-M appears in some units.
• Look for any retrofits: perhaps certain axes or control boards have been replaced. That’s double-edged: good if high quality work; bad if non-standard or no documentation.
• Wiring, connectors, motors, switchgear: check for water/coolant ingress, signs of overheating, insulation degradation, coolant leaks inside cabinets.
• All motion drives (servo motors, encoders, linear scales if fitted): test accuracy, backlash, drift.
• Safety features, interlocks, guards—these are essential both for safety and sometimes legally required.
• Diagnostics: does the machine have error logs; can the control diagnose position drift, spindle issues, etc.?

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4. Grinding Spindle, Wheel & Mandrel System

• Condition of grinding wheel spindle: balance, vibration, run-out. Any damage to the spindle nose, taper, mounting.
• Mandrels / head systems: check that internal hole grinding mandrels are straight, well aligned; check radial clearance; test with small hole grinding, taper if needed.
• Wheel dressing / truing systems: are they still in good condition; the dressing tools and systems should be precise, properly working.
• Coolant delivery: sufficient flow, high pressure, correct filtration; cooling is critical to prevent heat damage and burns.

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5. Performance / Accuracy Testing

• Do a test grind: perhaps with a known jig or fixture that has known hole pattern; measure hole diameters, spacing, concentricity, positional accuracy.
• Check repeatability: drive positions, return to zero, measure error.
• Thermal stability: let machine warm up; run it grinding for some time; measure if parts drift. Heat from spindle and grinding causes distortions.
• Under load: do heavy workpieces, large internal holes, long tool life; see how spindle and machine hold up.
• Multi-axis / coordinated hole grinding: if 6 axes, test coordinated motion; check for any slop in rotary axes.

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6. Wear, Consumables & Spare Parts

• Mandrels, fixtures, tool holders: are they worn? Are exact replacements available locally or with reasonable lead time? Costs of mandrels / fixtures sometimes high.
• Wheels, bonding, mandrel materials (CBN / diamond etc.) – cost and availability.
• Parts for spindle bearings, encoders, servo/drives, control boards. If these are obsolete, you may be stuck.
• Consumables: coolant, filters, dressing tools. Are they in usable shape; does the machine need many replaced / cleaned?

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7. Logistics, Setup & Environment

• Physical size, weight: these machines are large (often ~4-4.5 tons or more), heavy footprint. Check whether your facility can handle transport, rigging, foundation, floor load, leveling.
• Power requirements: voltage, phase, current; stable clean power; possibly special power for high-speed spindles / turbine heads.
• Cooling / fluids, filtration systems: are they present, functional, or will you need to upgrade?
• Environment: temperature stability, humidity, vibration, dust. Jig / hole grinding is precision work; environmental control helps.
• Delivery, installation, calibration costs. Sometimes seller may provide re-alignment, or you must hire someone.

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Red Flags / Warning Signs

These are things that, if present, should make you either walk away or demand a large discount / repair before purchase.

• Spindle vibration, noise, excessive run-out that cannot be fixed easily.
• Severe wear or damage to guideways/crossrails, e.g. scoring, rust, pitting—especially where lubrication was neglected.
• Missing or heavily worn mandrels, fixtures, tool holders; non-standard / modified parts with no documentation.
• Control system is obsolete or undocumented; replacements or support unavailable.
• Excessive backlash or slop in rotary / coordinate axes (especially if machine is 6-axis, with rotary or swing components).
• Cooling or fluid systems that are nonfunctional, leaking, contaminated.
• Evidence of past damage/repair: cracks, welds, deformations.
• Lack of maintenance or records; unsure history.
• Excessive downtime or inoperative functions when you test on site.
• Machine stored in poor environment: outdoors, exposed to moisture, temperature extremes – these degrade parts fast.

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Cost / Financial Considerations

• The purchase price is only part of the cost. Include shipping, installation, foundation, leveling, alignment, calibration, utilities. With large grinders, these costs add up.
• Budget for refurbishment: new spindle bearings, re-scraping ways, rebuilding fixtures, replacing worn mandrels etc.
• Downtime while commissioning / validating; lost productivity while operators familiarise with machine.
• Spare parts and consumables cost: mandrels, grinding wheels (especially exotic ones), dressers, coolant filters etc.
• Support / software / control updates: if control needs firmware updates, or some retrofits, cost may be nontrivial.
• Resale / lifetime value: machines that are well maintained, have available parts and support, sell better later; ones with obsolete controls or no documentation may lose value fast.

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Using Hauser S40-600 Specifics (versus “plain S40”) as Benchmarks

The “S40-600” version (as per listings) has larger workpiece capacity / table load in some cases (e.g. 800 kg), larger table width etc. So when someone offers a “S40-600”:

• Verify that the claimed “600” refers to table width, spindle-to-table height, load, or one of the axes. Make sure the claimed spec matches the machine in front of you.
• Larger capacity often means heavier structure, bigger motors, possibly different spindle head or cooling. But it also means more weight in transport, more power requirement.
• The larger the capacity, the greater the risk: any misalignment or structural distortion under load will show up when you load big workpieces. So pay extra attention to structural rigidity.

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Suggested Inspection Protocol

Here is a step-by-step process you can use on-site:

1. Pre-visit: Request detailed spec sheet, photos (especially spindle taper, mandrels, ways, cross-rail, fixtures), maintenance history, proof of accuracy (test data), plus list of replaced major components.
2. Site visit:
   • Warm-up the machine. Run idle for some time, then check spindle temperature, any vibration.
   • Run all axes through full travel, no load; listen / feel for smoothness. Measure backlash if possible.
   • Check spindle: test with dial indicators / run-out gauge; test taper cleanliness.
   • Test with fixtures / mandrels: do hole grinding (or a test job) and measure holes for size, concentricity, positional accuracy.
   • Apply load; see how machine handles workpiece weight.
   • Check coolant and dressing systems: dress a wheel, verify wheel truing; check coolant flow, heat control.
   • Check rotary / coordinated axes if any: make sure they move cleanly, no play.
3. Post-inspection: Get quotes for needed repairs; compare with cost of better machine or refurbished unit. Negotiate price accordingly (either include repairs, parts, or price deduction).
4. Ensure you can get some guarantee or at least seller commitment: for example, that critical accuracy or spindle run-out is within a certain tolerance.