[npolanosky]

Gents, I have a tough one for you (or maybe not, I might get lucky).


I'm getting a 410 Servo Alarm (B Axis Excess Error) on my KIA lathe with a FANUC 0i-TB.
I picked it up used about a year ago knowing it had some issues and it's only in the past month or so I've been able to get it into a shop with 3ph to power it. The subspindle axis driver and the B motor were out of the machine when I got it, so they had obviously run into this before.


Here's what happens:
Power up lathe.
Press Standby to enable servos and zero-return all axes.
Hydraulic pump comes on, servos get powered on, all is well.
B axis (subspindle linear axis) attempts to home.
B axis jerks + or - an inch or so and throws the 410 alarm.
No alarms on any of the servo amps themselves.


If I disable B by setting it's axis number to -128, I can jog the other axes (X/Z/C) but it will NOT run normally (can't run a program, turn on spindle, etc) presumably because it wants B at home for safety.


What I have observed:


B axis servo amp had missing solder on the main power bus bars inside. I repaired this, but it may indicate a problem with the driver. The subspindle servo does move though, so if it is damages it's (a) not throwing an alarm and (b) still moving the servo a fair bit.


The encoder reads position just fine, and after doing the P-CAN procedure and resetting zero with Param #1815 the home location and soft overtravels are in (at least the ballpark of, +/- 1/4") the right place.


The motor appears to move just fine and the tech I had out (who was also stumped by this) checked the motor and agreed it seemed ok. Resistance on all phases was the same, no ground issues.


I checked all of the parameters (yes, ALL of them. Took forever) and aside from a couple of minor discrepancies (backlash, machine on time, stuff like that) it all matched up.


Here's a video of the problem too, as well as a few minutes of me rambling about the aforementioned stuff:


KIA SKT21LMS problems and ramblings - YouTube


So my question is, what do you folks think is the problem? Should I throw a B axis drive at it and hope that's all it is ($1200 refurb on ebay or $3000 from Fanuc? Is it a software issue I can fix by changing parameters or resetting positions of something? Know how to fully disable the B axis so I can go about my regular turning and come back to this later? Have I stumped you as well?


Let me know, and thanks in advance. I'm happy to provide more info if I missed anything.

[zavateandu]

so if you have in 1815 APC and APZ to 0 it means the reference will be on the dog ,did you saw that dog???
if you have no dog for reference it means that the zero is on the motor and the APC and APZ must be 1,in your video i see them all 0.

first i should move the zero of that axis ,100 mm to the spindle side and see if it is the same.

[drdos]

If you can PM me your ladder I can make the machine run without the B axis.

[npolanosky]

How would I do that?
I have everything set up to try and send over serial, but I am stuck in MDI. The machine seems to think it's in Estop even though the switch isn't activated and as far as I can tell the limit switches are all clear. Ladder (if I am reading it right) indicates the switch is open, but does not change if I depress the Estop switch.

[npolanosky]

The E-stop button isn't pressed, and I don't have voltage at the button but I have continuity on the gnd line
It looks like there are maybe a few things in series with it that could cause this. I am not super familiar with electrical diagrams..anything jump out that would indicate what I should check next?
Relevant diagrams attached?

[npolanosky]

Replaced B axis driver, no change in behavior.

[npolanosky]

An update on this:
I replaced the B axis amp and motor/encoder and I finally have a screen clear of alarms HOWEVER I still can't jog or ZRN the B axis. I've tried resetting the zero with the 1815 param, I've tried manually moving it to the first inductive switch, I've swapped back to the original driver...no change in behavior. No alarms on control or on the amp. I power up, press Standby, press jog+zero return, and X and Z both ZRN properly. C will ZRN too. But B is unable to jog or ZRN.

Ideas?

[zavateandu]

An update on this:
I replaced the B axis amp and motor/encoder and I finally have a screen clear of alarms HOWEVER I still can't jog or ZRN the B axis. I've tried resetting the zero with the 1815 param, I've tried manually moving it to the first inductive switch, I've swapped back to the original driver...no change in behavior. No alarms on control or on the amp. I power up, press Standby, press jog+zero return, and X and Z both ZRN properly. C will ZRN too. But B is unable to jog or ZRN.

Ideas?

can you copy tbe ladder and nc parameters and send to us?
i am thinking that the B axis is disabled or you have an interlock on keeprelays.
[email protected]

[npolanosky]

What's the easiest way to do that? I haven't had succcess dumping them to a CF card, I just get an "IO ERROR 99". Haven't tried RS232 yet but I can do that next.

[zavateandu]

easy is by CF card but you can download via rs232 too,make the cable and by a usb to serial converter

[ktik]

Gents, I have a tough one for you (or maybe not, I might get lucky).


I'm getting a 410 Servo Alarm (B Axis Excess Error) on my KIA lathe with a FANUC 0i-TB.
I picked it up used about a year ago knowing it had some issues and it's only in the past month or so I've been able to get it into a shop with 3ph to power it. The subspindle axis driver and the B motor were out of the machine when I got it, so they had obviously run into this before.


Here's what happens:
Power up lathe.
Press Standby to enable servos and zero-return all axes.
Hydraulic pump comes on, servos get powered on, all is well.
B axis (subspindle linear axis) attempts to home.
B axis jerks + or - an inch or so and throws the 410 alarm.
No alarms on any of the servo amps themselves.


If I disable B by setting it's axis number to -128, I can jog the other axes (X/Z/C) but it will NOT run normally (can't run a program, turn on spindle, etc) presumably because it wants B at home for safety.


What I have observed:


B axis servo amp had missing solder on the main power bus bars inside. I repaired this, but it may indicate a problem with the driver. The subspindle servo does move though, so if it is damages it's (a) not throwing an alarm and (b) still moving the servo a fair bit.


The encoder reads position just fine, and after doing the P-CAN procedure and resetting zero with Param #1815 the home location and soft overtravels are in (at least the ballpark of, +/- 1/4") the right place.


The motor appears to move just fine and the tech I had out (who was also stumped by this) checked the motor and agreed it seemed ok. Resistance on all phases was the same, no ground issues.


I checked all of the parameters (yes, ALL of them. Took forever) and aside from a couple of minor discrepancies (backlash, machine on time, stuff like that) it all matched up.


Here's a video of the problem too, as well as a few minutes of me rambling about the aforementioned stuff:


KIA SKT21LMS problems and ramblings - YouTube


So my question is, what do you folks think is the problem? Should I throw a B axis drive at it and hope that's all it is ($1200 refurb on ebay or $3000 from Fanuc? Is it a software issue I can fix by changing parameters or resetting positions of something? Know how to fully disable the B axis so I can go about my regular turning and come back to this later? Have I stumped you as well?


Let me know, and thanks in advance. I'm happy to provide more info if I missed anything.

Hi, I have the same problem on a machining center on the X axis. I changed the cables and the motor to the Y axis and it has the same problem, so it is not mechanical. Could you help me by telling me how you solved the problem? Thank you.

[servtech]

Gents, I have a tough one for you (or maybe not, I might get lucky).


I'm getting a 410 Servo Alarm (B Axis Excess Error) on my KIA lathe with a FANUC 0i-TB.
I picked it up used about a year ago knowing it had some issues and it's only in the past month or so I've been able to get it into a shop with 3ph to power it. The subspindle axis driver and the B motor were out of the machine when I got it, so they had obviously run into this before.


Here's what happens:
Power up lathe.
Press Standby to enable servos and zero-return all axes.
Hydraulic pump comes on, servos get powered on, all is well.
B axis (subspindle linear axis) attempts to home.
B axis jerks + or - an inch or so and throws the 410 alarm.
No alarms on any of the servo amps themselves.


If I disable B by setting it's axis number to -128, I can jog the other axes (X/Z/C) but it will NOT run normally (can't run a program, turn on spindle, etc) presumably because it wants B at home for safety.


What I have observed:


B axis servo amp had missing solder on the main power bus bars inside. I repaired this, but it may indicate a problem with the driver. The subspindle servo does move though, so if it is damages it's (a) not throwing an alarm and (b) still moving the servo a fair bit.


The encoder reads position just fine, and after doing the P-CAN procedure and resetting zero with Param #1815 the home location and soft overtravels are in (at least the ballpark of, +/- 1/4") the right place.


The motor appears to move just fine and the tech I had out (who was also stumped by this) checked the motor and agreed it seemed ok. Resistance on all phases was the same, no ground issues.


I checked all of the parameters (yes, ALL of them. Took forever) and aside from a couple of minor discrepancies (backlash, machine on time, stuff like that) it all matched up.


Here's a video of the problem too, as well as a few minutes of me rambling about the aforementioned stuff:


KIA SKT21LMS problems and ramblings - YouTube


So my question is, what do you folks think is the problem? Should I throw a B axis drive at it and hope that's all it is ($1200 refurb on ebay or $3000 from Fanuc? Is it a software issue I can fix by changing parameters or resetting positions of something? Know how to fully disable the B axis so I can go about my regular turning and come back to this later? Have I stumped you as well?


Let me know, and thanks in advance. I'm happy to provide more info if I missed anything.

First up, I would remove the sub spindle motor and see how tight the axis is, by first turning the ballscrew by hand, and then with a torque wrench at a gradually increasing ft/lb setting.

If there is a clamping brake on the axis, release it. Check the motor turns freely by hand, it may have a brake or not.
The 410 alarm is stating that the axis has been commanded to move and it hasn't or not within in setting parameters.

[zavateandu]

The excess erro could be from many reasons but after watching your movie it seems is not mechanical as the axis is moving ok by hand ,i was susspected the clutch/coupling between the motor and the balscrew but i think is ok.
So there is what i should do if i am in front of your machine:
-i would disconect frst time the coupling between the motor and ballscrew and let the motor turn free without moving the B axis support
-i would try to move the B axis motor by jog and see the current monitoring by watching the MONI screen to see if the motor overload
-in many cases i had the problem with the power cable of the motor that had one wire broken and the excess error was on until i just remade the cable
-also in the diagnose you will find a lot of information about movement and error
-when you make zero return on B axis make a movie with the diagnose 360,361,362,when you will see the motion commanded from the CNC ,the motion from servo and the motion from the encoder so you can see the difference between these
-also make a photo of the diagnose between 200-208 where there is also info about error
-if you want to use the machine without B axis can be done by ,like you said,-128 on parameter and lso you have to disable the reference return signal not to be checked at pwer on.
That can be done in 2 ways,from a specific parameter or if the MTB put it in the ladder by bypass the sequence with a keeprelay

Good luck