26/09/2025 By CNCBUL UK EDITOR Off

Technical Buyer’s Handbook: Assessing Pre-Owned , Used , Secondhand, Surplus CNC Machines Before Purchase COILTECH PRO 80 – 100 – Servo Feeder made in Türkiye

Below is a draft Technical Buyer’s Handbook / Due-Diligence Checklist tailored for evaluating a pre-owned / used / surplus COILTECH PRO series (e.g. PRO 80-100) Servo Feeder (or equivalent) before purchase. You can adapt it (add/remove items) depending on your use-case, budget, and risk tolerance.

This is intentionally detailed; you may choose which items are “must-check” vs “nice-to-check” depending on the deal size.

1. Pre-Assessment & Preparatory Steps

Step	Purpose / Questions	What to Collect / Do Ahead
Define your functional requirements	Ensure that the candidate machine is appropriate for your process	Required coil width, thickness, feed speed, acceleration, stroke length, tolerances, integration with downstream press/tooling, control interface
Collect all available documentation from seller	To verify claims and reduce unknowns	Original manuals (electrical, mechanical, pneumatic), spare parts list, wiring diagrams, maintenance records, serial number, modifications history
Ask preliminary questions	To screen out obviously unsuitable offers	How old is the machine? Has it been in continuous operation or standby? Why is it being sold? What parts have been replaced? Is it currently running? Can you see it under power inspection?
Request photos & videos	Visual clues often reveal much	Exterior, interior panels, wiring, drive components, running in-feed / out-feed motion, roll surfaces under motion (if possible)
Understand spare parts availability & vendor support	Risk mitigation	For COILTECH / HESSE / related servo feeder brands, are key parts (rollers, bearings, encoders, belt/gearbox, servo motors, electronics) still available locally or via suppliers? Coiltech in Turkey does produce servo feeders.

2. On-Site / Physical Inspection (Before Running)

Below is a checklist to go through before powering up (if possible), and in tandem with powering up.

2.1 Visual & Structural Checks

Frame, body, mounting surfaces
Check for cracks, weld repairs, deformation, misalignment, bending.
Roller / feed rolls
Look for surface wear, pitting, corrosion, misalignment, flattening, run-out.
Bearings & shafts
Check for play, discoloration (overheating), lubrication condition, looseness.
Gearbox / transmission / belts / couplings
Inspect housing for leaks, damage; check belts for wear, cracks; couplings for misalignment.
Encoder, feedback devices, sensors
Inspect for damage, cleanliness, alignment.
Wiring, cabling, connectors
Loose wires, frayed insulation, overheating marks, exposed shielding, loose terminals.
Electrical panels, drives & control units
Open cabinets if allowed: look for signs of burning, corrosion, dust accumulation, moisture ingress.
Pneumatics / hydraulics / air supply (if used)
Check hoses, valves, cylinders, seals, fittings, pressure conditions.
Limit / safety switches, guards, interlocks
Verify that guards & covers are present, functional, and not bypassed.

2.2 Alignment, Geometry & Kinematics Checks (manual / low speed)

Roller alignment & parallelism
Use dial indicators or straight edges to verify feed rolls are parallel and coaxial.
Axis / slide guideways (if applicable)
Check for smooth motion, binding, scoring, lubrication.
Backlash / slop
Manually move axes (or feed mechanism) to detect slack, play.
End stops / homing / limit travel
Verify limiters operate and are not overridden.
Encoder feedback vs mechanical travel
Where accessible, move mechanism and see if encoder reading matches movement (coarse check).
Flatness / planar reference
Use surface plates or reference planes to check that machine is not warped.
Lubrication systems
Confirm that lubrication lines are intact, no clogged or missing parts, check oil levels if gearboxes have oil reservoirs.

3. Power-Up & Functional Testing (Under Power / Dynamic Checks)

If allowed, run the machine under controlled conditions. For a servo feeder, feed movement, acceleration & accuracy are key.

Test	What to Observe / Measure	Acceptable / Warning Signs
Power-up / boot diagnostics	Control boots cleanly; error/warning messages	Persistent errors, alarms or inability to initialize are red flags
Homing / referencing	All axes / positions home correctly and reliably	Inconsistent homing, large offsets
Feed motion (acceleration / deceleration)	Does it follow expected profile? Inspect for jerk, vibration, stalling	Excess vibration, inconsistent motion, slipping
Repeatability / positioning accuracy	Feed a test strip or marker, measure deviation vs nominal	Deviations beyond spec tolerance (e.g. >±0.05 mm if spec)
Maximum speed test (gradually increasing)	Ramp up to nominal speed and slightly beyond	Motor overload, torque drop, slip or current spikes
Load / torque test	Use a small dummy load (sheet, coil) to test under typical working conditions	Loss of motion, current limit trips, overheating
Thermal and stability test	Run extended period to see temperature rise in motors, drives, gearbox	Excessive heat, drift, thermal expansion causing errors
Interrupt / sudden stop / reverse test	Test emergency stops, reverse motion, abrupt deceleration	Mechanical instability, lost position, noise
Sensor / limit / safety test	Trigger limit switches, safety interlocks to ensure machine stops or responds correctly	If safety fails or continues operation, unacceptable
Noise & vibration monitoring	Listen, feel vibrations, check for unusual noises	Grinding, knocking, bearings failing, gear noise

4. Measurement, Calibration & Accuracy Validation

Use calibrated gauges, micrometers, dial indicators to measure actual output vs commanded motion.
Inspect the feeding accuracy: feed 1 m, measure actual displacement, see cumulative error.
Use a test strip with markings to see if alignment drifts during feed.
If possible, integrate with downstream tooling briefly to verify feed registration / repeatability with tooling.

5. Documentation & Records Review

Maintenance / service logs
Check routine services, major overhauls, part replacements, downtime history.
Spare parts replaced
What major components (servo motor, gearbox, encoder, bearings) have been replaced, when?
Modifications / retrofits
Any non-stock modifications — check whether they were professionally done or “ad hoc.”
Calibration / alignment certificates
If previous owner had calibration, inspection, or alignment checks, review them.
Original technical documentation
Control manuals, wiring diagrams, electrical schematics, user manuals.
Warranty / guarantee / seller promise
If the seller can offer short-term warranty or “as-is foot-in guarantee,” that reduces your risk.

6. Risk Assessment & Cost Forecasting

Remaining useful life of wear items
Estimate how many hours left on rollers, bearings, belts, gearbox, servo motors before replacement needed.
Spare parts cost and lead time
Check local / regional suppliers and lead times for key components.
Calibration / alignment overhead
You may need to re-set or re-calibrate after relocation.
Transport & installation risk
Disassembly, reassembly, alignment, foundation, leveling, utilities, vibration isolation.
Downtime and opportunity cost
Time to bring the machine to production from delivery.
Residual / salvage value
If things fail, what salvage value remains?
Obsolescence risk
Control electronics, firmware, interface compatibility with your existing systems.

7. Negotiation & Contract Clauses (Purchase Safeguards)

Price adjustment based on condition findings.
“Acceptance test” clause: allow you to test after installation (e.g. 30 days) and reject or adjust price.
Spare parts package / inventory transfer (bearings, belts, O-rings, sensors).
Seller to deliver full documentation, drawings, wiring, program backups.
Guarantee that no hidden defects (e.g. encoder damage, motor winding faults) exist at time of delivery.
Transport / insurance clause: who bears risk in transit.
Payment tied to successful performance acceptance.

8. Specific Considerations for COILTECH PRO 80-100 Servo Feeders (or equivalent)

Because the COILTECH / HESSE brand and PRO series is relatively specialized, here are specific points you should be aware of:

The PRO series servo feeders are used for coil feeding, straightening, and controlled sheet feeding. For instance, the PRO 100 model (by HESSE / COILTECH) is specified for ± 0.05 mm coil feeding accuracy.
Verify the encoder / feedback system is original, in tolerance, and not substituted arbitrarily.
The gearbox / drive coupling: many units use helical / bevel gear drives; check wear in those precisely.
The roll diameter & material: ensure the feed roll diameter (e.g. 80 mm) is as spec and material is appropriate (hardness, coating).
Check the maximum feed speed / acceleration capability (e.g. 75 m/min, 10 m/s² in some models) and confirm the candidate machine can reliably reach it.
Confirm control & interface compatibility: if your press / cutting tool chain uses a particular communication protocol (e.g. digital I/O, fieldbus, PLC interface), ensure the servo feeder can match.
Because COILTECH is Turkey-based, you might have relatively easier access to local support or parts (depending on your location).
If the machine has been idle for a long time, seals, bearings, lubrication may have deteriorated more than usage implies.

9. Sample Inspection Scoring / Decision Matrix

You may find it helpful to build a scoring matrix. Below is a template you can adapt:

Inspection Area	Weight (%)	Score (0–10)	Comments
Structure & Frame Integrity	15
Rollers / Bearings / Wear Items	20
Drive / Gearbox / Transmission	15
Encoder / Feedback & Controls	15
Electricals / Wiring / Panels	10
Dynamic Performance (speed, repeatability)	15
Documentation & History	5
Spare Parts / Support Risk	5