Hi, I first want to say what a great help this site and forum has been to me in the last week. I used the info I've found here to return my machine to Z zero after it got lost. I am also getting close to figuring out my rs232 communications with what I have learned here.

Which brings me to my curent problem. "servo alarm -01 overload". And of course a "machine not ready" message. I was running the machine and it started sort of squeeking(very slightly) in the X-direction. It ran for about 20 - 30 minutes before freezing during a cut in the x- direction. I immedietly got the 2 alarms and havnt been able to do anything to get them to go away. I pulled off the covers and can move the ball screw, back and forth approx 1/10th of a turn before it seems to hit a stop. My first question is what did I break? and secondly, is there something I can do to move my Z out of the way while I fix the X drive problems? I almost forgot, the machine has a Fanuc controler. Thanks to who ever responds.

If its an older Fanuc control. There is a red reset button on the bottom of the axis drive slightly underneath the top board. Try pressing this reset and power down then up.

Thanks for the reply Petro! :) It is a older fanuc as far as Im concerned. Yellow end caps on the servo motors and the Fanuc controller is a 3M version I think. I will try this tonite and let you know what i find out. Thanks again!

Thanks Petro! :) I had to look around a little and it didnt appear to be tripped. I reset it anyway and turned off the machine and restarted it. Everything is working great now, except for the noise from the X-axis. With the covers off it is quite noisy. If I use the hand wheel and rock the X back and forth .010 there is a clunking/loud clicking noise. If I feed the X it clunks at first and then squeaks. The clunk noise seems to be coming from the black section of the servo motor. Any ideas?

There are generally only a few things that can cause axis clunking noise.
Loose ballscrew nut capturing the bearings on either end or bad bearings (most likely the cause).
Way covers sometimes clunk due to wiper friction
Ballscrew nut slop
No lubrication on ways

Thanks again Petro. I went ahead and pulled the servo motor tonite, but didnt get a chance to pull the bearing on the end of the ball screw. When I turn the ball screw by hand it is very smooth and no noise at all. I am wondering if I can hook the servo motor back up to its electrical conections. But not hook it up to the X axis and move the motor with the hand wheel so I could keep track of movement. So I could listen for noises from the motor. Would this work or would the motor lose its "home position"? Does the motor have a Home position?

It depends on what type of encoder the motor is using. If you have absolute encoders with no reference switches you will lose home. If you have incremental encoders the axis will feed to limit switches at the positive and negative ends of the stroke and base zero off of the distance between the two.

If you do have absolute encoders you should rezero the axis anyway since the motor or ballscrew either one could have moved once you removed the motor from the coupling.

Cody Stamper



(Note: The opinions expressed in this post are my own and are not necessarily those of machinetoolhelp.com and its management)

Thanks codyst. I have limit switches so I turned the machine on and its definitely a bad bearing in the servo motor. I pulled the motor out and cleaned it up. I removed the hub from the shaft end and pulled off the cap and encoder also. I marked each of their home positions but am not sure if it matters? Im going to be pulling the motor apart tomorrow night. Do either of you have any pointers for taking one of these apart? Are the bearings/seals something I can get from a bearing supply house? Is there anything else I should replace while I have it apart? Thanks very much for all your help.

I'm not sure about those motors. I've pulled a few red caps apart, but I've never even seen a yellow cap.

Cody Stamper



(Note: The opinions expressed in this post are my own and are not necessarily those of machinetoolhelp.com and its management)

I didn't even think about it being an older motor. If its a yellow cap then its a DC motor. It has brushes that can be removed and replaced. Often when they wear down it can sound like a bad bearing. The brushes are generally about 3/4 to 1" long when new for reference. Also the powder from the brushes and surface the brushes ride on can sometimes cause problems. But before pulling apart just change the brushes if they are worn.

I should have said they were the yellow cap/DC motors. Sorry about that. The brushes are about 3/4" long and look good to me. I am pretty sure that its a bad bearing unless something came loose inside and was causing the clunking and squeaking. I have signed up over at Fanuc and am hoping to be able to get some parts drawings before i take the servo motor apart.

I pulled the motor apart tonite and both bearings are shot. I am going to try and find some locally and get this machine running tomorrow. Thanks again for all the advice Petro, and codyst. I will let you know how it all works out.

I replaced the bearings and put the motor back together. Got it back on the machine and was able to zero the machine. The bad news is within seconds of running the machine/program, the noise started again. And in about a minute it overloaded. This was the first the first motor I have ever taken apart, and Im now guessing that the noise/problem is coming from 3 of the 4 magnet strips not being attatched to the outer body/tube. I wondered if that was ok when it was apart, and Im now guessing its not ok. Do you think that could be the problem? Is it possible to re attatch those magnet strips to the body/tube? Thanks for your time on this.

I went ahead and ordered some Loctite® E-20NSTM HysolTM epoxy adhesive. Its made to Bond magnets to the steel housing in DC motors. Petro, do you know anyone who has done this?

No I don't, I usually just order a new one if its not the brushes

I didnt think many people would try it. I have to admit if I was at work, and my boss asked me if I could repair a servo motor. I would have most likely told him no. This machine is a hobby based machine in my personal shop. Which is mainly a 1800 sf garage for all my personal projects/hobbies. I will give the glue a try and let you know how it goes. I should be getting the glue tues pm.

I got 2 of the magnets glued in the housing last nite. I ran out of room for clamps, so I glued the 3rd magnet in tonite. Tomorrow nite I will put the motor together and see if it works.

I now have a new alarm code. Its a servo alarm 11, (x axis). In rapid mode the machine moves approx .02 and then alarm. With the hand wheel it will move .0002 and then surge approx .32 and then alarm.

I took the motor apart and put it back together this morning. Now I get a servo alarm 02 (vrdy) It also trips the same reset button as the 01 overload alarm.

I walked away from this problem early Sat am. It has been all ive been concentrating on for a few weeks, and I needed to get some other things done. While I wasnt working on the servo motor it dawned on me that I might have got the magnets glued into place upside down. I know they are in the right place but might be 180 degrees out. Now I need to try and figure out how to get the magnets "un" glued from the housing and to figure out how to check for proper installation. I will let you all know what I end up doing.

Does anyone have a source for used servo motors?

Or possibly a new servo motor?

If it's the Loctite glue I'm thinking of, heat is going to be your only "unglue" solution.

As far as a new or used servo motor, I would probably start with Ebay, especially being a yellow cap. A quick search for Fanuc DC motors brought back 42 items. There are also some Ebay stores that have some of the older control stuff. There is also a company based out of Tennessee, that has older Fanuc products. They do a core charge if they have it in stock(they send you one, you send the bad one back, and they recondition it and knock off some of the price). I have a contact number for them at work, and can post that for you tomorrow.

And then there's always Fanuc. They may have one, but it will come with that nasty Fanuc price tag.

Cody Stamper



(Note: The opinions expressed in this post are my own and are not necessarily those of machinetoolhelp.com and its management)

Thanks codyst, I have found 2 on ebay that are very close. Im sending them some info on my motor to see if they can identify it. My motor's plate is blank except for 4 things.

(2000M) RPM?

84.11 Date?


B-481694 Serial #?

011 I have no clue.....

The glue is a 2 part epoxy type of glue and Im not sure how to break the magnets free yet. i had heard that heat was bad for magnets and was thinking of freezing the housing before trying to press the magnets off the wall with my Arbor press.

I dont think i can afford a new motor from Fanuc.

You're correct, heat typically isn't very friendly with magnets. You might be able to freeze it and get them off, but I'm not sure. I've done it to bearings with great success, but I've never tried it with something that is epoxied on.

The company that I mentioned is Tie. Their phone # is 615-471-5070. Website is http://www.fanucworld.com A few of my customers use them quite often and I've yet to hear a complaint about them. From what I gather, they sell it for new price, or whatever the going price is for a "vintage" Fanuc part, and when you send the old one back you get somewhere around 25% back as a core. Don't hold me to the percentage; the customer I was with today couldn't remember the exact amount he got back.

Cody Stamper



(Note: The opinions expressed in this post are my own and are not necessarily those of machinetoolhelp.com and its management)

Thanks for the number codyst. Im in the process of communicating with them to try and figure exactly which motor i have.

I have left the motor housing/magnet soaking in carb cleaner over nite in hopes of softening the glue some. I have got some info to determine which way the magnets are installed and now am pretty sure i only need to loosen up one magnet. i figure since the motor worked with 3 loose magnets with the proper orientation that i can recreate that with the magnet(s) loose before gluing them back in this time. I appareiate all your and Petros help with this and will let you know waht it takes for me to get the machine running again.

The carb cleaner had little to no effect on the magnet glue. I got a hold of the company that I got the Loctite glue from and they contacted Loctite for me. Loctite recomends heat, around 350 degrees or so. and they sell a glue softener. I ordered a pint of the softener. Its coming out of Chicago and should be here by Friday or so.

I also contacted the extremely nice people at fanucworld. I emailed back and forth with a lady named Peggie. Peggie was very nice and informative also. Fanucworld gets between $2800.00 and $3200.00 for a rebuilt and new fanuc servo motorslike mine. That price would just about blow my budget considering I got the whole machine for around $6500.00.

I also contacted a couple of people with used motors for sale on Ebay. Im not sure exactly which way im headed at this point but will keep you informed of my sucess's/ failures.

I have another contact here in Indianapolis that rebuilds servo motors. I'm not sure what it would cost for shipping and rebuilding, but I could give him a call if you like. It'd probably be Thursday morning before I could get in touch with him. I'm in Warsaw, IN until Wednesday but could get his number when I get back to the office.

Cody Stamper



(Note: The opinions expressed in this post are my own and are not necessarily those of machinetoolhelp.com and its management)

Any other contacts would be appreciated codyst. Thurs will be fine. Thanks!!

I'm re-installing 6 Star swiss type lathes, and 1 new Star swiss type, and was asked to extend my stay an extra day; so I won't be back until Friday. I'll try to see if someone can get his number out of my folder at the office and send it to me.

Cody Stamper



(Note: The opinions expressed in this post are my own and are not necessarily those of machinetoolhelp.com and its management)

I appreciate all your help codyst. Friday will be OK.

You can also try:

Servo Motors and Drives
(414) 281-7700
4040 W. Loomis Road
Greenfield, WI 53220

http://www.servomd.com

Ask for Scott, and tell him Robin at Tri Star CNC told you to call.They do a GREAT job rebuilding Fanuc motors!

Robin