Z stall error

[atldal]

So awhile back I discovered a crack in my z truck and had to order a new one. I got the part yesterday and put it on today. Upon putting it on I ran a test and got a z stall error. I tried running it without the belt attached and get the same error. The motor runs free and there does not appear to be any binding on the parts. I'm extremely frustrated and now at a total stand still. Any ideas on what I can do to trouble shoot this?

[Digitalwoodshop]

A Z Stall error where you say that the Motor IS Running after you disconnected the Z Drive Belt... Tells me the computer is NOT seeing position feedback and that feedback would be the ENCODER PULSES......

Since the Encoder Pulses go through the FSC Cable then that is my first choice:razz:.... Then the Plug on the Z Motor BOARD or even the Encoder on the back of the Z Motor...

All checked by going to Options, Sensor Data, and Z Data.... Once you call up the Z data it will display 0000 and when you move the motor shaft by hand it will show pulses... 0001, 0002, 0003.... and move it back and 0003, 0002, 0001 and 0000....

Let us know what you find.... It could be a loose FSC Cable but likely a ripped cable..

AL

[atldal]

The motor isn't running, it just turns freely by hand. Sorry for my poor wording in the original post I just reread it.

[bergerud]

That still sounds like the FFC wire could be the problem as Al said. The controller sends power the motor and expects the encoder on the motor to confirm movement. If the power is not getting to the motor, the encoder will not signal movement and the controller will report a stall. It is easy to interfere with the FFC wire when performing major surgery on the machine. I would suspect the wire or the connection to the carriage.

Edit: did you completely remove the z motor pack when you changed the truck? ie. unplugging the motor power wire?

[Digitalwoodshop]

Then FSC Cable is still #1....

Then the Plug on the Servo Motor... It IS possible to plug it in 180 out... but not likely...

Then the back of the motor is the other end of the plug that goes into the encoder board taking power into the motor and power to the encoder and pulses back to the computer.

IF the FSC Cable was pulled out while the power was on then that could cause an arc that could take out the Z Servo.

Do you have the Designer upgraded to do a Z Test through the keypad? That might help....

Do you have any spare parts? Motors? FSC Cable?

AL

[atldal]

I did originally when I was first trouble shooting things. If I do a continuity check on the cable it should show a break I would think. I will check that.

[Digitalwoodshop]

Because the FSC Cable is a flat copper wire between plastic, it cracks and as you flex it, the ends meet and not meet... So laying it flat could give you a false good...

DO the other Axis work in a Test? Could be the Power Supply if not...

You do have the 14 pin FSC cable not the old 18?


AL

[atldal]

A Z Stall error where you say that the Motor IS Running after you disconnected the Z Drive Belt... Tells me the computer is NOT seeing position feedback and that feedback would be the ENCODER PULSES......

Since the Encoder Pulses go through the FSC Cable then that is my first choice:razz:.... Then the Plug on the Z Motor BOARD or even the Encoder on the back of the Z Motor...

All checked by going to Options, Sensor Data, and Z Data.... Once you call up the Z data it will display 0000 and when you move the motor shaft by hand it will show pulses... 0001, 0002, 0003.... and move it back and 0003, 0002, 0001 and 0000....

Let us know what you find.... It could be a loose FSC Cable but likely a ripped cable..

AL

So I moved it by hand and got no pulsing at all.

[atldal]

Because the FSC Cable is a flat copper wire between plastic, it cracks and as you flex it, the ends meet and not meet... So laying it flat could give you a false good...

DO the other Axis work in a Test? Could be the Power Supply if not...


AL

I checked all other axis and they test fine

[Digitalwoodshop]

Did you unplug the Servo Motor Cable at any time? And got it 180 out on install? The Cable on the side of the motor to the board to the FSC Cable.

NO Pulses = the encoder is not getting power most likely and no return signal... check both ends of the FSC Cable and the big plugs that plug into the lower board?

A Risky test.... Would be to un plug machine and remove the Z Motor... Un plug the Y Motor Cable and plug the Z Motor into the Y Motor power then power up and do a Y test and see if the motor moves... Be sure to hold the lose Z motor.... It is risky but would half split the troubleshooting... The Trick is to make sure you un plug the machine before plugging and un plugging...

Another thought.... The FSC Cable is ONE Sided.... Any chance it is twisted and the plastic side is to the contacts side?

AL

[atldal]

Unfortunately I think I unplugged everything at one time or another. In looking at all the cables, I'm sure they are in correctly because of the cable glue that was originally in it. That is what makes me totally lost with this. Is it possible the motor is bad? Is there anyway to check that outside of the machine?

[Digitalwoodshop]

Since NO Encoder Pulses and No Movement... That tells me for both to be out.... It has got to be a open servo motor plug... as in 180 out... Or the FSC Cable 180 out..


A Ohm Meter check of the Servo Motor would do.. but since Un Related things.... Servo Driver and Encoder are OUT it must be something in common.... Like above...

AL

[atldal]

I tested the FSC cable tonight and it is fine, no breaks. I also made sure every other cable is plugged in correctly. I still only get slight movement out of the motor and then a z stall. This occurs if the z truck is attached or off. Still at a total loss.

[Digitalwoodshop]

So we are to a point that you need to call LHR Hardware Tech and go through the procedures they recommend...

1. You need a new Motor

2. You need a new Computer as the Servo Driver is inside the computer. That is going to be expensive... IF the FSC Cable was removed while the power was on then that can blow the servo driver.... When at Sony making Picture Tubes I replaced many little servo drivers like this... I have never done one in the CW.


3. FSC Cable... or related circuit boards. I know you tested them.. but because you did not get encoder pulses.... Still think it is a common item between the encoder and drive and that would leave a cable or circuit board.

IF it were ME, I would plug the Z motor into the Y but it can be risky and LHR needs to be in the loop when you do.

AL

[bergerud]

Check the encoder disc at the back of the z motor. If the motor moved, it is connected and maybe the signal was turned off because the controller did not get any encoder data telling it that the motor moved. The disc may be cracked or stuck, or dirty??

Another thing to do is to do a sensor check on the z position. Turn the motor by hand as you look at the z data on the LCD. (press 0 - 7 - down X 3)

[atldal]

Check the encoder disc at the back of the z motor. If the motor moved, it is connected and maybe the signal was turned off because the controller did not get any encoder data telling it that the motor moved. The disc may be cracked or stuck, or dirty??

Another thing to do is to do a sensor check on the z position. Turn the motor by hand as you look at the z data on the LCD. (press 0 - 7 - down X 3)

What is the best way to clean these?

[atldal]

So we are to a point that you need to call LHR Hardware Tech and go through the procedures they recommend...

1. You need a new Motor

2. You need a new Computer as the Servo Driver is inside the computer. That is going to be expensive... IF the FSC Cable was removed while the power was on then that can blow the servo driver.... When at Sony making Picture Tubes I replaced many little servo drivers like this... I have never done one in the CW.


3. FSC Cable... or related circuit boards. I know you tested them.. but because you did not get encoder pulses.... Still think it is a common item between the encoder and drive and that would leave a cable or circuit board.

IF it were ME, I would plug the Z motor into the Y but it can be risky and LHR needs to be in the loop when you do.

AL

I'm pretty sure it isn't the Servo Driver as I didn't remove the FSC Cable prior to troubleshooting this issue

[bergerud]

Take the back off of the z motor (two screws) and you will see the encoder disc inside. It is a clear plastic disc with very fine radial lines on it which are read by the optical reader. This tells the computer how far the motor has turned. I am thinking that it is not working. The computer sends power to the motor and when it gets no encoder signal back, it thinks the motor is stalled and cuts the power. That is my theory anyway. (Actually, I think the encoder has cracked and fallen off!)

First, however, you should test it. 0-7-down X 3 on the keypad and then turn the motor by hand. If the z numbers change nice and smoothly, my theory is wrong. If the z numbers do not change smoothly, it is probably the encoder and you should take the back off of the z motor and have a look.

[atldal]

I have had that off and It does not look like it is cracked in anyway. I don't get any change in the numbers when I test it.

[bergerud]

So the encoder looks ok yet the encoder data is not making it to the computer. I would now try, as Al suggested, connecting the y motor in place of the z motor and try the sensor check again. (I assume the y sensor data does change when you do the sensor check.) If switching the y motor gives sensor data, then the z motor encoder is somehow bad. If there is no change, then you are back to wiring or some other electronic failure.

[atldal]

So the encoder looks ok yet the encoder data is not making it to the computer. I would now try, as Al suggested, connecting the y motor in place of the z motor and try the sensor check again. (I assume the y sensor data does change when you do the sensor check.) If switching the y motor gives sensor data, then the z motor encoder is somehow bad. If there is no change, then you are back to wiring or some other electronic failure.

So can a person just buy that encoder and board or do you have to purchase a whole new motor?

[bergerud]

I believe you would have to buy the whole z pack, gears and all. I would do the switch first to know for sure if it is the z motor pack. (I think you could also plug the z motor into the y board to test. That might be easier since you would not need to unbolt the y motor pack.)

[Digitalwoodshop]

I would try to re seat the big plugs with the ear clips..... and the computer end too...

Replacing the Encoder would be a challenge EVEN to me.... As the BIG solder pads for the Servo Power would be hard to un solder and you could over heat the motor end. The Slits...

And I worked on board level work at Sony and I even have a Hot Air soldering station.

In picture 4, inspect for missing mini surface mount resistors.... The little rectangle things with silver ends. R1 to R5.

AL

[atldal]

So I switched out the motors and get a reading with the y motor in both y and z and nothing from the z motor. Appears it is the encoder and I will be ordering a new z motor. Thanks for all the help I will post after I get the new motor and let you know how it went.

[Digitalwoodshop]

So I understand you that a Y Motor WORKS in the Z Position Correct? That tells you that the FSC Cable is Good as you expected.

Look at my pictures... The little Z Encoder has that plug attached on the back of the motor... The pin from the plug goes into a copper donut and is soldered. The donut has a copper trace leaving the pin area going to the encoder... In my Circuit Board Experience I am betting that the DONUT and the TRACE are Broken.... This happens when the jack is not pushed all the way into the hole then soldered... Then vibration lets the jack push into the board causing the donut to snap the connection.... A Soldering Iron and some flux could re flow the connection and you would be back in business... IF you can reach the underside of the board to solder it...

Order a FSC Cable while you are at it... Save Shipping later...

AL

Edit: I just looked at Picture 2 of my Post 5 and you can't get to it.... :(

[atldal]

So I got a new z motor today and so far so good. I think back to all the z stall errors I was getting and now believe that it has been bad for awhile either the sensor or the motor. Hope this is the final fix for a bit as I'm broke!

Thanks for all the help.

Shane