Servo motor repair in India
Multi-brand repair, alignment and load test.
Servo motorsEncoder alignment and programming
Servo motor encoder alignment, testing and programming
Encoder alignment sets the feedback device's position to the rotor's magnetic poles, so the drive switches current at the right moment. Star Automations tests servo motor encoders and resolvers on a universal feedback tester, aligns them to the rotor, and on supported serial encoders, including Fanuc, Yaskawa and Tamagawa types, reads and programs the encoder memory. Every motor is then proved with a run test and a full-load test.
01Symptoms
Signs of a misaligned encoder
A misaligned encoder often looks like a motor fault. The motor turns, but it does not deliver torque cleanly.
- High current at low torque, or the motor runs hot
- Rough running, cogging or noise that changes with direction
- Overcurrent or overload trips soon after start
- Position or following errors on the machine
- The motor runs one way but not the other
02When it is needed
When alignment is needed
Encoder replaced
A new or repaired encoder must be aligned to the rotor before the motor goes back.
Winding work
After winding repair, the offset must be checked even if the encoder was not touched.
Rotor or bearing work
Disassembly can disturb the encoder mounting. We check the offset after every rebuild.
Unexplained alarms
When a motor trips but tests healthy electrically, the offset is one of the checks.
03Feedback devices
Feedback devices we test and align
Alignment is part of the repair. The motor comes in, the feedback is tested, repaired or replaced, aligned and then proved under load.
The tester covers incremental, absolute, serial and resolver feedback across the major encoder makers, including Heidenhain, SICK Stegmann, Hengstler and Tamagawa.
- Incremental encoders with UVW or Hall commutation tracks
- Sin/cos encoders (1 Vpp)
- Resolvers
- Absolute encoders: EnDat, BiSS and BiSS-C, SSI, parallel absolute
- SICK Hiperface and Hiperface DSL
- Serial encoders: Fanuc, Mitsubishi, Yaskawa, Tamagawa and MFE types
- Hall effect sensors and tachogenerators
04Encoder memory
Encoder memory read and programming
Many serial encoders store data the drive relies on, such as the commutation offset or encoder alignment angle. If that data is lost or wrong, a motor with a good winding and a good encoder will still alarm or run badly.
We read the full encoder memory and record it before work starts. After repair, or when a replacement encoder is fitted, we write the data back on supported serial encoders, including Fanuc, Yaskawa and Tamagawa types, then check alignment on the tester and run the motor.
Other serial types, such as Mitsubishi, are read, checked and aligned on the tester. Send the nameplate and the encoder part number and we confirm what applies to your motor.
05Verification
How alignment is checked
We read the encoder or resolver on our servo motor test system and compare its electrical angle with the motor's back-EMF. The offset is set, locked and re-checked, then the motor runs in both directions with no load and under full load, and current is compared with the nameplate.
The measured offset and the run results are recorded on the test report. See the real tester screens and run test.
06Report
What the report records
| Item | Recorded |
|---|---|
| Feedback device | Type and part number as found, and as fitted |
| Encoder memory | Data read before work, and data written back where programmed |
| Offset | Measured offset before and after alignment |
| Run results | No-load and full-load speed and current in both directions, compared with the nameplate |
| Result | Released, or not released with the reason |
See a sample test report.
08How to send
How to send the motor
You can send a servo motor from anywhere in India. Talk to us before you courier, so the unit is expected and logged on arrival.
Send the nameplate
WhatsApp a clear photo of the nameplate, the alarm code and what the machine was doing when it failed.
We confirm repairability
We tell you whether we can test and repair that model before anything is shipped.
Courier or pickup
Courier the motor to our Chennai, Puducherry or Bengaluru site, or ask us to arrange pickup where needed.
Inspection and quote
The motor is opened, inspected and photographed. You get the findings and a quote before work starts.
Repair, test, dispatch
Repaired, run-tested and load-tested, then dispatched with a printed test report.
What is encoder alignment?
Setting the encoder's zero position to the rotor's magnetic poles, so the drive commutates correctly.
Can I just fit a new encoder?
Not on most servo motors. Without alignment the motor may run rough, overheat or trip.
Which feedback devices do you align?
Incremental encoders with commutation tracks, sin/cos encoders, resolvers, EnDat, BiSS, SSI, Hiperface and Hiperface DSL encoders, and Fanuc, Mitsubishi, Yaskawa and Tamagawa serial encoders. Send the nameplate and the feedback type.
Do you program servo motor encoders?
Yes, on supported serial encoders, including Fanuc, Yaskawa and Tamagawa types. We read the encoder memory, write it back after repair or encoder replacement, and check alignment before the motor runs.
Is alignment checked under load?
Yes. After alignment the motor runs with no load and then under full load on our rig.
Do you repair the encoder too?
Where possible, yes. If it cannot be repaired, we source an equivalent and align it.
Send the nameplate. We confirm repairability before you courier.
WhatsApp a nameplate photo and the alarm code to +91 97866 22233, or email info@starautomations.com.