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Fanuc Encoder Repairs

mjk

Titanium
Joined
Oct 20, 2005
Location
Wilmington DE USA
I have a Fanuc A860-0320-T113-3000P ABS Pulse coder from the Y axis of my 1994 TNC vmc

from one repair shop I've rec'vd an evaluation:

"Glass and mask have been rubbed and are bad"
non repairable

I'm having the encoder sent back to me.
Is this a a problem that can be fixed by a shop with differant skills, or do I need to find a a new encoder?

Mike
 
I have had them apart before and it sounds like that diagnosis is correct, there is a thin glass disc inside with various timing marks or whatever you want to call them etched in. Any other markings on the glass will make the encoder read incorrectly. Shop around, pricing on those things are all over the place.
 
The key part of the encoder is the disk and its markings. If that is truly shot, then all of the value of what remains is minimal. Google your part number and you will find options.
 
Try Tennessee Industrial Electronics, they sell remanufactured units (615) 471-5070.
 
TIE didn't have the encoder by itself

I've been in touch with all the Google and Bing hits today in the USA, and attempted to read languages from countries I didn't know existed in other parts of the world
 
I need to vent to someone who may understand my immediate pain

This morning I received my encoder back from the repair shop. Although I've been told a glass rub is a kiss of death I did have a conversation with 2 repair shops that said it is remotely possible to repair.
Wasn't I surprissed when a differant encoder was returned to me!
The day can only get better?

Mike going to take my first Excedrin of the morning
 
Can you somehow get a hold of a Fanuc know it all that can tell you what other encoders may work by just altering a few parameters? I am guessing there may be a sub, maybe not. Try calling CNC Electronics in Virginia (434) 971-1394, they do Fanuc board repair, they might know another source for encoders.
 
Sorry man, TIE and CNC Electronics are the only ones I have used for like parts. The good news is you have isolated the trouble. Keep watching E-bay maybe one will eventually turn up. You might have to farm some stuff out till you get the machine repaired. I was in the same boat, had two machines down after my move for months. I was upfront with the customers and let them go elsewhere, fortunately they received poor quality parts and I got them back.
 
yeah, just have 1 vmc, just about to start 1st production run of a a new product line
waiting for a quote back fitting my style motor with an ABS3000 encoder


Fanuc just told me no stock avaialable for my a new motor

And I thought classic cars was an expensive stressfull endevor
 
Have you searched for a used motor with encoder? Sometimes the entire motor is more readily available as many who scrap out machines do not disassemble beyond major sub assemblies.

Of course there is the risk that the encoder is bad in the used motor but you can wiegh the risk verses your immediate need to get running.

Also check with these guys Servo Motor Repair - Servo Repair Experts | Servotech USA as they repair a lot of encoders and may be sitting on a replacement.
 
Update 8/2
machine is back up running
Servotech Incorporated in CT put together a refurbished motor with a differant style 3000 pulse encoder
I gave a verbal goahead last Friday to put it together, shipped my core out Monday
They shipped the replacement Wednesday, arrived this morning
Not sure if every motor shop does this on repairs, but the motor has been repainted and a new Fanuc style decal applied, a little attn to detail, hopefully a hint as to their other skills
1 year warranty, pricing was more than I could afford but more than fair considering the turnaround time

Mike
 
What did you pay, I would think that set-up would run $2500 at a minimum? You didn't have to alter any parameters? Glad it is running.
 
No parameter change as the encoder pulse qty was the same
had to move the axis home trip dog 1/16"

1 hour after receipt of motor machine was back running
still have to replace sheet metal, but I've been running a startup program to cycle machine, along with shutting down and starting up. No issues

this weekend to do 3 weeks work................
 
Yes its an old thread but a followup and a repeat of good service.

When the above motor/encoder was installed I had already switched the working X axis motor to the Y to eliminate a possibility of anything that wasn't the motor causing the problem.
After the 2012 repair I had the rebuilt motor on the X axis and the original X axis motor on the Y axis.

Within the last year I was having to do the "P" "CAN" at startup to allow Y axis to home.


Early August 2020 and that and changing par 701 wouldn't allow the Y axis to home.

Checked all the "easy" things, and decided to swap out the X axis motor (8 year old rebuild) into the Y axis location.
It worked , but the original Y axis motor in X gave same errors.
Called Servotech and got a "worse case scenario price" for a rebuild, bit the bullet and sent the motor in for repair.

Encoder diagnosed as non repairable and the rebuild involved a modification to use a new non-tapered mount encoder, bearings and power socket .
The motor was back in about a week(I had not paid for rush service).
As before the motor looked like new.

Installed the motor in the X axis without issue and everything worked fine with homing the machine.
Shut it down and started it up several times and then ran a warm up program that loops until reset .
After about 15 minutes as I was in the other end of the shop I heard the spindle stop.

Look at the monitor and error 414,424 & 434 oh crap.
My first thought was the newly rebuilt motor.
Tried restarting, no change.

Called Servotech and worked with Mike the owner.
Thru some basic diagnostic tests with an ohm meter and removing motors from the system I found it was the Y axis motor.

Since the error went away when the power connection was disconnected from the Y axis motor, Mike felt that it was possible there was a winding issue that I couldn't detect with the equipment I had.
Since the error code went away but the cable from the servo amplifier was still connected, that cable should be fine.

What it turned out being was the power connector (machine side ) to the Y axis motor.
The bakelite was decomposing allowing 2 of the female pins to move back when the connection was made.
Upon taking the fitting apart, the back half had signs of coolant.
I installed a new connector, luckily having enough extra cable to to give a clean end and now the machine has been running all week without an issue.
I'm a 1 man shop and was treated like one of the big guys.
Thanks Servotech.


mike
 
Have you searched for a used motor with encoder? Sometimes the entire motor is more readily available as many who scrap out machines do not disassemble beyond major sub assemblies.

Of course there is the risk that the encoder is bad in the used motor but you can wiegh the risk verses your immediate need to get running.

Also check with these guys Servo Motor Repair - Servo Repair Experts | Servotech USA as they repair a lot of encoders and may be sitting on a replacement.


This was going to be my recommendation.
You can likely buy a whole used motor ready to go for the cost of a new encoder, plus you will have a spare motor. (your original)

Another option is to search google for a Fanuc motor manual download and find the page that covers the motor numbering codes, and then find any other motor with the same suffix related to the encoder.


OK, didn't git that it was an 8 yr old thread 'till now, but I will leave the reply up.


-----------------

Think Snow Eh!
Ox
 
Ox

Your thinkin to much bout snow....yes replying to an 8 year post but with additional info about a repeat good experience with Sertvotech.

Although the encoder was beyond repair my reason for posting was reminding those about the other what appears unseen problems...a disintegrated piece of bakelite that was also a problem. The overcurrent alarms 414.424 & 434 could have easily have thrown up the flag of "Replace the Servo Amplifier" in some shops.
The connector was the clam-shell/split design and on the Y axis which has the motor and connections just inches from the coolant flow.
Today's work involves creating a better chip removal tray.
An auger or conveyor just isn't an option with this machine
 








 
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