[1988]

I want ask that I am using xinje servo motor & drive and I am facing one problem. When position reset command is given to the motor through HMI it takes one full rotation and gets reset to home position. But when there was no problem then it was only rotating 10 degree to get reset to the home position. What is the problem happening plz solve my issue

[mactec54]

I want ask that I am using xinje servo motor & drive and I am facing one problem. When position reset command is given to the motor through HMI it takes one full rotation and gets reset to home position. But when there was no problem then it was only rotating 10 degree to get reset to the home position. What is the problem happening plz solve my issue

It's just using the Z-Pulse / index Pulse, which is one Pulse per revolution of the encoder, so wherever it is, and you do a Reset it will move to the Z-Pulse / index Pulse position.

Homing is different where it will backoff until it finds the Z-Pulse / index Pulse position. this also can be in the software a setting as to how far it backs off.

[1988]

It's just using the Z-Pulse / index Pulse, which is one Pulse per revolution of the encoder, so wherever it is, and you do a Reset it will move to the Z-Pulse / index Pulse position.

Homing is different where it will backoff until it finds the Z-Pulse / index Pulse position. this also can be in the software a setting as to how far it backs off.

Thanks for your reply
I am new to servo motors and don't have related software. How can I rectify this one full rotation reset process bcoz there is no room for full rotation reset in the machine it will damage other components. Actually this servo motor is used in surgical mask manufacturing for earloop holding purpose. This type of same servo motor used in opposite side just rotates only 11 degree not 360 degree for resetting its home position. Plz suggest any solution for this issue

[mactec54]

Thanks for your reply
I am new to servo motors and don't have related software. How can I rectify this one full rotation reset process bcoz there is no room for full rotation reset in the machine it will damage other components. Actually this servo motor is used in surgical mask manufacturing for earloop holding purpose. This type of same servo motor used in opposite side just rotates only 11 degree not 360 degree for resetting its home position. Plz suggest any solution for this issue

The programing is what controls how the Reset works so if you want it the same you would have to change it in the PLC or move the positioning of the motor spindle so that it does not have to do that much movement, so you may be able to disconnect the motor spindle and move it 3/4 of a turn. if it is not close to the Index-Pulse it will do a full turn or until it finds it.

[1988]

The programing is what controls how the Reset works so if you want it the same you would have to change it in the PLC or move the positioning of the motor spindle so that it does not have to do that much movement, so you may be able to disconnect the motor spindle and move it 3/4 of a turn. if it is not close to the Index-Pulse it will do a full turn or until it finds it.

Thanks for your reply

I will first disconnect servo motor while encoder cable connected and then set motor shaft such a way that while resetting it finds z-pulse immediately. And then connect the motor terminal and then will full system reset

[1988]

Thanks for your reply

I will first disconnect servo motor while encoder cable connected and then set motor shaft such a way that while resetting it finds z-pulse immediately. And then connect the motor terminal and then will full system reset

What is electronic gear ratio? I want to know concept and how its is determined?

[mactec54]

What is electronic gear ratio? I want to know concept and how its is determined?

The Electronic Gearing enables the servo motor to travel distance per input referance pulse to be set to any value, this allows the controller to control the movement per Encoder PPR

This would be setup in the servo drive in relation to the number of pulses needed to move to a distance, so you have to know what the encoder resolution PPR is, Incremental or Absolute, plus whatever the motor is driving, Ballscrew / Belt drive Etc. Ratio, then you can calculate the PPR needed to move a set distance

[Al_The_Man]

If in fact it is using the encoder Z pulse to set zero and it has dramatically changed, it could possibly be that the encoder to motor coupling has moved?
Either that or what ever couples the motor to the load has changed position, for that system I would think there is a set up procedure when the system was designed.
For Electronic gearing, there is also systems out there where one or more servos can be geared off of an encoder on a separate motor, ratio can be changed, even on the fly.
This is done in such as Galil Motion Systems etc.

[1988]

If in fact it is using the encoder Z pulse to set zero and it has dramatically changed, it could possibly be that the encoder to motor coupling has moved?
Either that or what ever couples the motor to the load has changed position, for that system I would think there is a set up procedure when the system was designed.
For Electronic gearing, there is also systems out there where one or more servos can be geared off of an encoder on a separate motor, ratio can be changed, even on the fly.
This is done in such as Galil Motion Systems etc.

Yes I have understood z-pulse encoder concept. And your assumption about the coupling disalignment is right. But I haven't pratically performed troubleshooting this problem. I will mention the day I successfully solve that problem.

- - - Updated - - -

The Electronic Gearing enables the servo motor to travel distance per input referance pulse to be set to any value, this allows the controller to control the movement per Encoder PPR

This would be setup in the servo drive in relation to the number of pulses needed to move to a distance, so you have to know what the encoder resolution PPR is, Incremental or Absolute, plus whatever the motor is driving, Ballscrew / Belt drive Etc. Ratio, then you can calculate the PPR needed to move a set distance

Thanks

[Al_The_Man]

Just be aware that if the motor is a BLDC type, then the encoder usually has commutation track as well as the typical pulse encoder track.
In this case the encoder should not be moved relative to the motor shaft as it will upset the commutation position.
It would be more likely that the motor shaft position relative to load has changed, coupling etc.

[mactec54]

Just be aware that if the motor is a BLDC type, then the encoder usually has commutation track as well as the typical pulse encoder track.
In this case the encoder should not be moved relative to the motor shaft as it will upset the commutation position.
It would be more likely that the motor shaft position relative to load has changed, coupling etc.

Good thought, but no one uses such a motor type on machines like this today.

[Al_The_Man]

Good thought, but no one uses such a motor type on machines like this today.

I certainly do.
I can use simple transconductance (torque mode) drives and mix and match motors & drives of different makes.
But you need a control where the CNC loop is closed in the controller. Galil Motion, Kmotion/Kanalog etc,
BLDC have slightly higher torque for their equal sized AC counterpart, in spite of being identical in construction.

[mactec54]

I certainly do.
I can use simple transconductance (torque mode) drives and mix and match motors & drives of different makes.
But you need a control where the CNC loop is closed in the controller. Galil Motion, Kmotion/Kanalog etc,
BLDC have slightly higher torque for their equal sized AC counterpart, in spite of being identical in construction.

Yes, anyone could do that, if they want to be 20 years behind, they use simple PLCs to program these pick and place machines.

[Al_The_Man]

Yes, anyone could do that, if they want to be 20 years behind, they use simple PLCs to program these pick and place machines.

What Rubbish.!
If I can achieve industrial grade CNC control (not Mach3 etc) for an efficient method at low cost I have achieved the same thing.
BTW FWIW PLC's can control a PID loop with the right add-on module., but in my case I use a High speed closed loop PID control to achieve results demanded by a modern CNC controller.
Incidentally I have modified surplus Fanuc AC servo's which range in the 1hp to 10hp range to BLDC by replacing the proprietary AC commutation encoder with a BLDC version and used them for C axis spindles .
If I were to hand you a dismantled AC servo motor and a BLDC version, I would defy you to tell the difference.
I have found that people often tear things down that they do not fully understand!! :drowning:

Definitely the case here!

[mactec54]

What Rubbish.!
If I can achieve industrial grade CNC control (not Mach3 etc) for an efficient method at low cost I have achieved the same thing.

What's the point this has nothing to do with CNC controls, so I guess you would be confused.:wave:

BTW FWIW PLC's can control a PID loop with the right add-on module., but in my case I use a High speed closed loop PID control to achieve results demanded by a modern CNC controller.

No PID loop is required to go to any control for these types of machines, it would be done in the servo drives, which is more efficient than any other way, when using modern Servo Drives. Things have changed from 20 years ago

Incidentally I have modified surplus Fanuc AC servo's which range in the 1hp to 10hp range to BLDC by replacing the proprietary AC commutation encoder with a BLDC version and used them for C axis spindles.

I'm sure you have, but this would not compare with the mega torque servo motors they use today for C & B axis, this also has nothing to do with this thread.

If I were to hand you a dismantled AC servo motor and a BLDC version, I would defy you to tell the difference.

If you say so, that must be the case then.

[1988]

The programing is what controls how the Reset works so if you want it the same you would have to change it in the PLC or move the positioning of the motor spindle so that it does not have to do that much movement, so you may be able to disconnect the motor spindle and move it 3/4 of a turn. if it is not close to the Index-Pulse it will do a full turn or until it finds it.

I have tried everything but motor takes full rotation to reset itself. There must be glitch in plc programming thats why motor behave like this while resetting. Encoder drive motor everything is ok.

[Al_The_Man]

If you have another machine of the same type, it may be possible to do a little reverse-engineering to find out what procedure is used.
It would either be by position, or to move to the zero point.
But position would infer that the machine recognize zero first at power up, I would think.
Can you move the motor shaft WRT the attached operating device ?
What test have you done so far?
Is this a system built in-house or obtained elsewhere?
If the latter the MTB should be able to help.
What make PLC is it?

[1988]

If you have another machine of the same type, it may be possible to do a little reverse-engineering to find out what procedure is used.
It would either be by position, or to move to the zero point.
But position would infer that the machine recognize zero first at power up, I would think.
Can you move the motor shaft WRT the attached operating device ?
What test have you done so far?
Is this a system built in-house or obtained elsewhere?
If the latter the MTB should be able to help.
What make PLC is it?

I have moved attached coupling to the motor repositioned at various angle but all in vain. Other machine servo motor first move little backward direction and then move forward direction to find zero position and position itself to offset setpoint in HMI. But in this motor reset procedure is not like others. This motor only move forward direction to find zero position which makes it to rotate 360 degree even if it in zero position. I have checked every component, all are good and healthy. So, I concluded that may be there is glitch in programming and logic in reset procedure of this motor.

We are using Chinese PLC of make: Xinje

[Al_The_Man]

I am not familiar with that PLC, do you have the software to view the ladder logic in order to see what is going on in the program?

[1988]

I am not familiar with that PLC, do you have the software to view the ladder logic in order to see what is going on in the program?

No