Every line below is performed in house by Apex Mechtronix Pte. Ltd. at 30 Petain Road, Singapore - 208099, Singapore (SG). We do not sub-contract the electrical or mechanical work, which keeps the release record in one set of hands.
A · Station one
Servo Drive Rebuilds
A servo drive rebuild starts with a controlled strip. The chassis is opened on a grounded mat, the DC bus is discharged and verified, and every removed fastener is bagged by position rather than thrown into a tray. The power stage is inspected for thermal damage, the electrolytic capacitors are measured for capacitance and ESR, and the gate driver board is checked for cracked solder at the device leads.
Rebuild means replacement of the parts that predictably age: bus capacitors, cooling fans, thermal pads, filter inductors where they have drifted, and any relay that has logged high cycle counts. The heatsink is cleaned, the fan shroud is re-seated, and the enclosure gasket is renewed where the customer environment is dusty or humid.
Proof is the part that separates a rebuild from a repair. The drive is run against a known motor with a load bank, and we record supply current, heatsink temperature rise, bus ripple and current-loop step response over a defined soak period. The trace is attached to the job card. If the drive does not meet the release standard, it stays in the bay.
M · Station two
Control Board Refits
Many control boards arrive already repaired by someone else, with no documentation and no trace of what was changed. The refit begins with a full visual and electrical survey so the board is understood before it is touched. We photograph both sides, note every prior rework, and test the supply rails under load before chasing the reported fault.
Where the fault is traceable, we repair rather than replace. That usually means a failed regulator, a dried-out capacitor near a hot component, a cracked joint at a connector, or a worn card-edge contact. The refit replaces tired passives in the affected area, cleans flux residue with the correct solvent, and re-inspects the board under magnification.
Every changed reference designator is written to the customer file, along with the reason for the change. A control board that leaves the bay should be readable by the next technician, and the file is what makes that possible. Boards that cannot be saved without a full redesign are reported honestly, with the failed sections identified.
X · Station three
Motion Stage Alignments
Motion stage alignment is mechanical work with a measurement habit. The stage is set on a granite surface plate, the rails are checked for straightness and parallelism, and the carriage is swept through its full travel with an indicator on a rigid stand. Any error larger than the stage tolerance is corrected with shim stock rather than forced with fastener torque.
Once geometry is within tolerance, every mounting fastener is torqued to schedule in a cross pattern, and the measurement is repeated after torquing because fastening can move a light frame. Squareness between axes is checked with a reference square and a dial indicator, and the coupling is inspected for angular and radial misalignment.
The release sheet records the measured values before and after correction, the shim sizes used and the torque values applied. That record matters when a machine later drifts, because it shows whether the drift is mechanical wear, thermal growth or a control problem rather than a return of the original fault.
P · Station four
Encoder Recalibrations
An encoder that is recalibrated against a reference scale can be trusted; one that is simply re-zeroed cannot. We clean and inspect the scale, the read head and the coupling, then compare the encoder reading against a reference through the full travel of the axis. Deviations are plotted, not averaged away.
For absolute encoders we verify the battery and the multi-turn store, reset the offset and confirm that the position survives a power cycle. For incremental encoders we check the commutation offset, the index pulse and the signal quality at low speed, where marginal alignment shows itself first. Contaminated scales are cleaned with the correct method for the scale type rather than with a general solvent.
The recalibration report lists the reference instrument, its calibration status, the measured error at each travel point and the residual error after correction. Where the error cannot be brought inside tolerance, the encoder is retired and the replacement is fitted and recalibrated in the same visit so the axis does not sit waiting.
T · Station five
Cable Loom Replacements
Intermittent faults in moving systems are almost always loom faults. We replace looms rather than patch them because a repair in a flexing section rarely survives the next thousand cycles. The replacement is built with the correct conductor class, the correct bend radius and proper strain relief at both ends, and it is routed to match the original drawing unless the customer approves a change.
Each conductor is re-terminated with the specified contact and crimp tool, then pull-tested to a documented force. Shields are bonded at the correct end only, because bonding both ends of a shield turns a quiet machine into a noisy one. Where the original loom had no service loop, we add one, and we record the change on the drawing.
The finished loom is continuity checked, insulation tested and flexed through a short cycle test before installation. On site, the first run is monitored for current and temperature so that a mis-routed loom is caught in minutes rather than in the next night shift.
R · Station six
Preventive Service Cycles
Preventive service cycles are scheduled work that takes a machine out of production on purpose, at a time chosen by the customer, instead of on the night it finally stops. The cycle begins with a short review of the last job card and any fault history, so the visit is aimed at known weak points rather than a generic checklist.
On the machine, the cycle covers lubrication condition and level, belt and coupling tension, fastener torque at critical joints, fan and filter condition, connector seating, cable condition at the bend radius, and a short trace review of axis response. Anything outside standard is corrected on the visit where it can be done safely, and quoted separately where it cannot.
The written record is the product. Each cycle leaves a dated sheet with measured values, so the next cycle can be compared against it. Trends are more useful than snapshots: a fan current that rises slowly is a warning, while the same fan current measured once is just a number.
A useful enquiry includes the equipment make and model, the serial number, the axis or station involved, the fault as observed in production, and any recent repair history. Photographs of the nameplate and the installed location help more than a long description. If the hardware is already off the machine, tell us how it was removed and how it has been stored, because a board kept in a humid cupboard may need more than the reported repair.
Quotes are issued in writing, with the service line, the scope, the release standard and the expected bay time. Where diagnosis finds a different fault from the one reported, we contact the customer before proceeding, and the estimate is revised in writing. No additional work is started on a verbal approval alone.