23/10/2025 By CNCBUL UK EDITOR Off

From Inspection to Installation: What to Verify Before Buying a Pre-Owned, Used, Secondhand, Surplus Sanco SDL-7235 CNC 5-Axes Double Column Bridge Gantry Vertical Machining Center made in Taiwan

Before purchasing a used / surplus Sanco SDL-7235 (built in Taiwan) machining centre, it’s vital to perform a thorough inspection from top to bottom. Below is a detailed checklist—split into inspection before purchase and pre‐installation/installation readiness. You may wish to bring along a qualified service technician or machine tool specialist.

Inspection Before Purchase

Machine identity and specification verification
- Confirm the model is indeed “SDL-7235” as per the manufacturer’s catalog.
- Check the serial number, year of manufacture, and original configuration (spindle rpm, tool magazine size, control type).
- Compare with spec sheet: e.g., for SDL-7235 the table load is up to ~24 ton according to the SDL/SDM series spec.
- Ensure the machine was built by Sanco Machine & Tools Corp. in Taiwan, and not mis‐labelled.
- Check if the machine originally had the 5-axes option (you mentioned “5‐Axes Double Column Bridge Gantry”). Verify what axes are actually present: X, Y, Z travel, plus rotary axes if claimed.
Structural & mechanical condition
- Examine the main gantry columns, the bridging beam, the moving table/sub‐table for wear, cracks, bending or misalignment.
- Check linear guideways and ballscrews: for heavy machines like this, wear on the X/Y linear guideways (extra heavy duty as per spec) can be expensive to repair.
- Inspect the spindle head assembly: Are bearings in good condition? Any excessive play, runout or abnormal noise?
- Verify the home/limit sensors, axes travel stops, and the hydraulic counter‐balance system on Z-axis (the specification states Z axis movement is counter-balanced by hydraulic cylinder for exceptional stability).
- Table and surface: Flatness, condition of T-slots, absence of major gouges or damage.
Control system & drives
- Confirm which CNC controller is installed (spec sheet lists FANUC 0i-MF standard; optional Mitsubishi/Siemens/Heidenhain).
- Check the condition and version of the software, backup and parameter history.
- Test jog modes, axis motion, automatic tool changer (ATC) functionality (spec lists standard 24 tools, optional up to 60).
- Verify spindle speed and gearbox condition (spec lists 6000 rpm driven by gearbox).
Electrical & auxiliary systems
- Inspect the electrical cabinet, wiring, drive modules for signs of overheating, rust or corrosion.
- Check coolant system, chip conveyor, mist collector if present, tool magazine, lubrication system.
- Confirm whether heat compensation, linear scales, tool probe, workpiece measurement systems are present and functioning (these may be optional accessories).
- Ensure the power requirements fit your site (spec lists ~50 kVA).
Alignment, accuracy & performance tests
- Request or perform a test cut: measure dimensional accuracy, surface finish, repeatability.
- Use dial indicators or laser alignment to check gantry straightness, table flatness, orthogonality of axes.
- Check for thermal drift, vibration during heavy cutting, and the machine’s ability to hold tolerances under load.
- Review maintenance logs: what work has been done on bearings, guideways, ball screws, spindle rebuilds, etc.
History, usage and condition
- Ask how many hours the machine has run, what kind of parts it was used for (heavy mold work, high-cutting load, fine finishing).
- Check for signs of abuse (overloaded table, collisions, coolant leaks, rust).
- If possible, inspect in operation under load to get a feel for stability, sound, vibration.
- Verify part inventory: Are all original manuals, parts lists, service/maintenance records present? Are spare parts still available from Sanco for this model?
Documentation & compliance
- Ensure the machine has appropriate import/export documentation, compliance with local electrical/safety standards for your country.
- Confirm machine shipping history: Was it stored correctly, has it been moved multiple times (which may introduce misalignment)?
- Make sure the seller provides any warranty or condition guarantee, and clarifies inclusions/exclusions (e.g., fixture, rotary tables, probe, tooling not included).

Pre-Installation / Site Preparation (for shipping & installation)

Site infrastructure & layout
- Verify floor strength and area: this is a very large machine (double‐column bridge gantry type) so check required footprints, clearance for gantry travel, overhead crane or heavy lifting gear.
- Ensure you have adequate height for the gantry, moving parts, and crane for installation.
- Check power supply compatibility: voltage, phase, frequency and kVA capacity in your facility.
- Verify environmental conditions: good foundation, temperature control, ventilation (especially for heavy or high-precision cutting).
- Check access for delivery: loading dock, crane, connecting cables, moving part clearance, any required building modifications.
Foundation, levelling & alignment
- Plan for a proper machine foundation (often a concrete plinth) with anchor bolts, leveling pads, and vibration isolation if required.
- After placement, perform full machine level and alignment using leveling bolts, grouting if necessary, then realign all axes.
- Realignment should include column orthogonality, table flatness, spindle head alignment, linear scale calibration if present.
Commissioning & verification
- Once installed, redo the full accuracy tests: check zero return, repeatability, backlash, axis play, ball‐screw integrity under load.
- Perform trial runs with representative parts to ensure machine meets production requirements.
- Set up the tool magazine, check ATC change times, verify the tool life and magazine indexing accuracy.
- Verify the machine’s safety systems: interlocks, guarding, emergency stops, coolant containment, chip disposal.
- Update any machine parameters for your local use (units, language, feeds/speeds, tooling database).
- Ensure training for operators and maintenance personnel; have spare parts inventory for common wear items (guide shoe pads, seals, filters, spindle bearings).
Documentation & changeover
- Update documentation with your configuration: axes specification, tooling list, accessories fitted, any deviations from original spec.
- Set up maintenance plan: lubrication schedule, guideway inspection, belt/gearbox checks, coolant maintenance, spindle service.
- Confirm availability of any replacement parts specific to this model and local sourcing in your country / Europe.
- Consider whether any upgrades are beneficial (e.g., retrofit of more modern CNC, linear scale feedback, condition monitoring sensors) if machine is older.

Special Considerations for a Double-Column Bridge Gantry VMC like SDL-7235

Because the SDL series uses large moving table + bridge fixed columns design (or moving cross‐beam) the machine mass and rigidity are significant—any transport, removal or re‐installation must account for weight and deformation risk.
The “3 linear guideways mounted on X axis” option (for increased rigidity) should be inspected: are all three guideways intact? Are they equally worn or is one taking the load?
Because the Z axis travel is relatively long (e.g., 1200 mm standard) pay attention to Z‐axis sag, counter‐balance operation (hydraulic cylinder) and rigidity under load.
Tool magazine capacity and axis motion speed: If this machine will be used for high‐volume mold or die work, tool change time, spindle speed and axis acceleration matter a lot.
For 5-axes capability: If the machine has a 4th/5th axis (rotary table or trunnion), verify those axes carefully—indexing accuracy, backlash, gear wear, lubrication, control integration.