HOME / Q & A / About Controller / 1.Alarm Troubleshooting

●Questions about X Axis

Ans . 

When CNC-300/350 turn on power and execute X axis Home process, X axis servo motor can’t drive X axis smoothly or can’t go to HOME.

Control unit issue – MOT 19 X axis following error exceed, MOT 008 X axis loss pulse,finally issue X axis servo driver alarm ,3 alarms are group alarms.


To slove the problem , please turn off power first, then turn on power, then  MOT 019 MOT 008, MOT009 will be go away.

Please open the X axis slide way cover to check the slide way:  

  1. Switch mode to MPG status, use MPG to move the X axis slowly from maximum – direction to Maximum + direction, to check where have problem, for example, if there have any obstacle stop the X axis slide way. After X axis movement is very smoothly by MPG, then it can execute X axis Home again and solve the problem.
  2. Or take off left X axis servo motor cover then use 8 mm Hex wrench to turn the ball screw end manually to find the problem position.
    Video of how to check the X axis slide way:


Maintenance suggestion:

Since X axis not often running, it only works during Home X axis only. So, side of X axis slide way maybe not use, and it is dirty or rust, then caused X axis moving difficult during X axis move to center period.

Please use MPG to let X axis running from left to right direction for 1 time /per month, it can let X axis ‘s ball screw and slide way working no rust problem.

And clean and maintain the machine 1 time /per 6 months.        




When the CNC-300 is in the manual operation of the X-axis movement, the ALE11 and MOT-009 X-axis driver alarm happen , possible reasons will be :

  1. The connector CN2 of the X-axis servo motor encoder is loose
  2. The connector on the motor end is not locked well
  3. The green signal wire of the encoder is damaged or not contact well .

Please check it one by one in order.


Please check the steps 1, 2, and 3 on attached first.

NOTICE - If need to check the step 4 , please must check with skillful technician !


Video for the checking steps:


Ans .

Three possible reasons as below:

  • X axis servo driver damaged 
  • X axis servo motor damaged
  • X axis motor U,V,W cable damaged (Short circuit)


Please check :  Attached “TROUBLE SHOTTING”

  1. Servo driver : Turn off power and take out (Off) the U,V,W connector from X axis driver to disconnecting motor U,V,W power from servo driver, then turn on power again .
    If the ALE01 alarm go away  X axis servo driver is no problem → see No.2
    If X axis servo driver still shown ALE01 → X axis servo driver damaged and need to replace X axis servo driver.
  2. If X axis servo driver no problem:
    Please check servo motor connector and U,V,W cable wires between servo driver connector ? If any U,V,W wire damaged , it will cause short circuit problem and caused ALE01 alarm.
  3. If X axis servo driver and X axis U,V,W cable no problem , the possible reason is caused by X axis servo motor.


How to double check the X axis servo motor is damaged:

  1. Confirmed Y axis servo driver and servo motor is okay .
  2. Take off original Y axis U, V W connector and Y axis Encoder connector
  3. Connect X axis servo motor U,V,W connector to Y axis servo driver U,V,W connector
  4. Connect X axis MPG connector to Y axis CN2 (MPG) connector for testing X axis servo motor .
  5. Turn on power, if Y axis servo driver issue ALE01 alarm , it can confirm X axis servo motor was damaged.  

Ans .

MOT 008 , MOT 023 , MOT 019, MOT 009 is belong to one alarm which caused by MOT 009 X axis servo driver alarm .


ALE-06 : It is caused by over load reason .

Please check X axis slide way and X axis ball screw action smoothly or not.  

And check X axis mechanical parts (Ball screw, Pulley and keyless bush etc.) is no problem and moving by hand smoothly.  

Take off the X axis plastic cover and X axis servo motor cover , then use handle to turn the X axis ball screw manually , moving X axis by hand from right to left ,it is possible ball screw running too heavy or any obstacle stop at X axis slide way , since   left side slide way not often using .


ALE-11 and ALE-04 alarm: Most possible reason is caused by encoder cable.

Please check the all cable between electric box to servo motor end, maybe there is any broken or connection not perfect during middle section of the encoder cable, common happen at cable inside machine base range. 

Please check all the X axis encoder cable status.

Ans .

The home position as Machine zero position (X0, Y0, C0) 

Normally when turn on power, controller request to execute zero return (home), after finished zero return (home) process, the controller will use home position as machine zero position (X0, Y0, C0) , program is following the zero position to move first X and first Y point .

The controller system use Delta servo motor, the position memory is not in servo driver .X axis servo motor zero position will only get after perform X axis Home process.

If controller have the battery problem will issue the battery lacking power, but controller battery has long life and it will charge after power on.

If the controller lacking power and don’t solve the problem, it should loss all parameter, not only just X axis.


The possible reason of X axis shift problem:

A. X axis Home sensor adjusted

When execute X axis Home , the X axis Home sensor get signal at 97% , controller warning the signal not within 20-80% and issue alarm , it need to adjust X axis sensor .

After adjust, if adjust to nest 50% position , it’s possible shift one pitch 5.0 mm (X axis pitch: 5mm) , but at the same time controller will issue warning X axis Home position was change.  

B.Fixture not clamping

If operator use unstable clamping fixture or the fixing position is not same between first and second work-piece, it will make center of work-piece change, so keyway shift.

How to check if the fixture is not clamping unstable:

Install two dial gauge , one is touch work-piece outside diameter , another put on X axis slide , then execute X axis home process , check the two dial value is stable or not .

Change to another work-piece and clamp well , then check the sensor touch work-piece is with same value or not . It could change another work-piece , clamp again and check dial position to find the reason of shift . 

If dial gauge on X axis slide with same position, but dial gauge for work-piece OD wrong , it mean fixture clamping problem.


The possible reason caused by X axis servo driver damaged or X axis servo motor damaged .

Please check which one damaged by following method:

  1. Turn off power
  2. Change X axis driver CN2 to Y axis driver CN2 , 
  3. Change Y axis CN2 connect to X axis CN2 position
  4. Change X axis driver U,V,W connector to Y axis U,V,W connector , the X axis and Y axis exchange to each other.
  5. After change well then turn on power again.  Notice: Just turn on power, don’t move X axis or Y axis .
  6. Check X axis and Y axis servo driver display:
    If X axis servo driver damaged → Y axis servo driver should show ALE03 after exchanged .
    If Y axis display do not shown any alarm after exchanged → X axis driver is OK,
  7. Please check X axis driver screen display, it will show different alarm if X axis servo motor damaged.