Fanuc Spindle Motor Speed Sensor

[Shanghyd]

It looks like the previous owner took the speed sensor off the spindle on the lathe I bought from him.
I'm left with a brown plug that appears to go to the control cabinet wiring. I'm also left with a cut off wire that goes down in to the spindle. I'm guessing this is the thermal sensor wires.
If the above is correct, where can I get the cable/harness for the speed sensor? Seems to me the plug and cable are integral to the spindle motor.



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[generaldisarray]

does the lathe run?

[Shanghyd]

No. It will power up but is stuck at a 408 error. The spindle control board shows alarm AL-01, spindle overheat. I'm guessing it's because the spindle speed sensor is missing and the connector also goes to the thermal sensor in the spindle motor. It is very close to running. I bought a speed sensor from China because no one in the USA had one. It should be here soon.

[zavateandu]

asi read i really do not understand what is your problem?
Your spindle mototr has no sensor mounted?
is the red cap dismounted from the spindle motor???do you see sensor missing from spindle motor???
the black small connector is connected to sensor and the brown connector must have a similar one in the spindle motor square box where also are the power wiring.
you should find there the mother plug for that brown and the other 2 wires for thermal that were cuuted from there.
shw us some more photos from the spindle motor.

[Shanghyd]

You are exactly correct. The spindle motor has no sensor mounted.
The red cap is dismounted. There is no sensor because the person who sold me the lathe took it off and used it on another lathe.
He also took the wire with the small black connector and brown connector.
I have found the mother plug and the 2 wires for the thermal sensor that were cut.
Spot on. You described it better than I did.

I need to purchase a wire with the small black connector and brown connector.
I can not find where to purchase this wire.

[generaldisarray]

you might try TIE/Fanucworld?
You will need the motor part number for sure.

I dont even know what is inside the red cap on a ac fanuc spindle motor. Does it look like the inside of the older ac spindle motors, toothed ring and a pickup? I kind of thought the red cap spindle motors had pulsecoders?
On the older ac spindle motors with the toothed ring, you needed an oscilloscope to tune the sensor.

[Shanghyd]

Looks like this.
It has the ring with lots of ridges around the edge.
I have a scope but have not used it much. Hope I don't need it for this.

[generaldisarray]

I hear tell the ring is very easily damaged, so fyi.
That is exactly how the older ones look, the sensor might be different maybe. The ring looks the same. Maybe on the newer ones you can just set the airgap and go.

Fanuc will tell you if you call and ask them for the procedure. You will need the motor part# and drive part#

[zavateandu]

you will not need the scope for it,you just need a shim of 0.15mm to put between the sensor and the teethed ring when you mount and tie the sensor on position.
Before you mount the sensor ,use a dial gauge(0.01 increment) that will touch the shaft and smoothly turn the spindle and check if is any radial run out of the shaft,if is around 0.01-0.02mm you are safe to mount new sensor,if it is not and you have a bigger radial run out,that means your back bearing is damaged and will easily break your sensor because the teethed ring will hit it during rotation---this is the main cause of 99% of the broken sensors,so be careful about this aspect.
about the cable,just take the sensor code for reference and google it.

I think here you will find your cable if you give them the code from the motor.
good luck.
https://avtechmachine.net/a660-8006-...6-t081-l240r0/

[Shanghyd]

Got the motor out so I can work on the harness a little easier. Attached is a picture with an arrow pointing to the thermal switch. Does anyone have a diagram showing where the thermal leads go? My harness has 6 wires that go to the speed sensor. I need to repair these thermal sensor leads and install them in my new harness. I need the diagram to know where they go. Any help is appreciated.

[generaldisarray]

You have now shown both ends of the orange molex? Your first pic and this one. the thermister leads usually just come up out of the windings and go into the connector. They have no polarity, it is just a resistor.

[Shanghyd]

No. The first picture is what I am looking for. I found something online that might work but it hasn't arrived yet. Since its not the exact harness I need I'll probably have to move the pins around the molex connector. It occurred to me that the harness I get will be missing the pins for the thermal sensor. Might be a non issue. I still need the pin outs for the other pins.

[zavateandu]

No. The first picture is what I am looking for. I found something online that might work but it hasn't arrived yet. Since its not the exact harness I need I'll probably have to move the pins around the molex connector. It occurred to me that the harness I get will be missing the pins for the thermal sensor. Might be a non issue. I still need the pin outs for the other pins.

can you say the motor code?should be a yellow sticker stick to it.

[Shanghyd]

Hopefully it is under the dirt. I think they painted the motor blue.


Attachment 405460

[Shanghyd]

Back with an update and a new problem.
I installed the harness. Everything is good to go there. I can enter a program and I can jog the machine.
The machine will error with 409 Spindle Serial Error, and the Error is AL-51.
"Under voltage at DC link section". The manual states to fix the error and restart the machine.
I'm reading 21VDC at the test pins on the spindle control board.
Any ideas how to troubleshoot this?

[generaldisarray]

The DC link refers to the DC bus should be ~300, at least on the newer power supplies.
I am guessing you have the older drives without the common Power supply? Since you axes work.

[Shanghyd]

I think they are separate but the axis stop moving when the alarm comes up.
There is a sandwich of 3 boards that drive the spindle. Is this where the DC Volts comes from? I'm thinking its the big old capacitor.

[Shanghyd]

I'm not going to bother posting here. You cant diagnose problems over the internet. There are too many variables. People are just guessing. There is not support for any machine more than a few years old. Waste of time.

[Shanghyd]

I was wrong. Romi came through with the manuals I needed.