Fanuc 3tc spindle problems

[R.thayer]

I have been working on my Lebonde Makino lathe and now the only think wrong is the spindle won't spin up. When I give it a spindle command it makes the phase converter grunt and if you wait the spindle will turn but you can stop by hand and it spins very very very slow. Also the mdi screen shows no spindle speed commanded. The s address reads 0. It acts like the spindle has been told to turn less then 1 rpm or something is wrong with drive but I don't get any alarms. The only alarm I get is if I tell it to change gears from low to high it lells me it has not direction commanded.

[Al_The_Man]

What make/model of spindle controller is on it?
Al.

[R.thayer]

It has a siemens spindle drive, motors, and fanuc control.

[Al_The_Man]

It may be because of the fact it does not show in-gear by limit sw or Prox. sw. although generally you get an error if it does not show in gear after a certain time.
Try and locate the 2 Analogue input terminals and command a spindle speed by MDI and check the voltage on the terminals, it should rise above 0 to something between 0 & 10v depending on the S value.
Alternatively, remove the analogue connection and apply a 1.5v battery to the terminals, the drive ready has to be on for this test, again MDI a command.
This will tell if it is in the drive or a control problem.
Al.

[gridley51]

Have you got a gear commanded?It may be inching the drive to select a gear or waiting on a clutch engaged signal before it commands a speed.Siemens dc drives are easy to run of a battery box.The analogue in terminals are always 14 and 56.
I connect 63 and 64 to 9
65 to 9 through a toggle switch.Make sure switch is open.Close switch to power drive.
Battery to 14 and 56
Disconnect machine wires from the terminals before linking them.Ideally you only want 0.3 of a volt initially.8 volts will give you near enough top speed.Make SURE IT IS SAFE to energise the motor before you do it.
Another thing to check is continuity through the tacho,if it does not see the tacho it should not power up although I have had a Siemens spindle motor run away because it did not see the tach.
Check for field voltage as well you should see that when you enable the drive.
What model of drive is it.
Mark.

[cncdiag]

Have you checked you have field voltage

[R.thayer]

I have not checked any voltage as I don't understand these translated prints. I have tried to have it change gears but it acts like it needs to turn to switch into high. I have changed parameters 57-60 to 1000 rpms for all gears. This did not help. I also changed parameter 56 witch is spdlc witch is spindle offset compensation value. I put in positive 2000 and the spindle would not do anything and then I changed it to a negitive number and the spindle will turn but it is very very slow and it has no power. I can stop the spindle with my hand very easy. I should be able to look in the ladder to see what gear the machine is in right. I am not sure what model spindle drive I have but the book talks about feed drives and the number in the book is 6rb2025. Thank you guys for all your help. Also what would cause the axises to move when I am turning the power off to the control. I almost act like a cap discarging or a field discarging. I don't know

[gridley51]

The 6RB is quite a common drive.You can download manuals for that from the Siemens site,but very hard to find.I might have a pdf somewhere.
When you say the spindle is turning slowly is the motor also turning slowly?Or is the motor running normally.Have you looked to see what speed the control thinks the motor is doing?
Check with a meter what voltage you get on terminals 14 and 56 on the spindle drive when the motor is running.It should be between 0 and 10 volts dc.
When I get a problem like this I always run the drive of a battery independent of the control,this lets you determine if the fault is drive or control.You can do this with spindle and axis drives.When you have proved that the drives are ok or otherwise then start looking at the rest of the machine.
I would also change the parameters back to what they were.Unless you had lost the parameters and reloaded them and were not sure if they are correct or not it is better to leave them alone in case you bring in other problems especially if you don`t understand how the parameters affect the operation of the machine.
The fact that it`s not blowing fuses holds hope that there is not too much wrong here.
Mark.

[R.thayer]

I thought I knew where the spindle drive was but I am not sure now. The board that I thought was the spindle drive has a number on it 6rb2000. I looked in the books and I found a print that says main spindle drive. Is the spindle drive in a rack all by itself or is it in with the axis drives? I can find the termanials 63-64 side by side witch they have 22 volts coming from them. I also found 3 large wires that I think go to the spindle motor. It shows them on this print as going to the spindle motor. I have the drives enabled and I get 45 volts accross these wires. There is a ground wire and two black wires about .312 in dia. I have looked this print all over and can't find terminal 56. Can you point me in the right direction as far as where this spindle drive would be. Thank you once again you are a life saver. How do you know so much about siemens drives?

[gridley51]

You may be looking at the axis drives instead of the spindle drive.Are the cards in a row edge on or are they in a frame one behind the other?
The three large blacks could be the three phases going to the drive.
The two blacks may be the motor wires.
I don`t suppose you could post pictures or scan the prints and email them to me.
I only know a bit about Siemens stuff,not it all.It comes from being in central Scotland,three hundred miles away from the nearest good board tester/repairer and the fact that you are looking at a cost of $1200-$2000 for a repair.When a machine goes down and the job has to go out the door you learn to be self sufficient.I have a lot of Siemens drives on my machines,6RA`s,6RB`s,610`s and 611`s.Siemens 6T,810 and 820 controls.I`m also not bad on GE2000`s and Hiak drives.
Try and get more info and I`ll try to help.
Mark.
www.ems-fife.co.uk

[R.thayer]

Please send email address to jen61304 at yahoo dot com. I not need spam so I wrote it out. Lets say that the ground and two black wires is the spindle motor power. If the drive is enabled what should the voltage be from ground to the black wires. Also the axis drives are on edge in a rack. In the book it calles these axis drive and then one basic board. Then there is another rack that the main power comes into. This has board one behind the other. I looked in there and still did not find terminals that you stated before. There is one board that has a bunch of leds on it. I will try to get some picture very very soon. Just send your address and I will send them to you. So you are like me try to do things yourself. It saves alot of money and problems in the end I think. Once again thank you and hope to hear from you soon.

[Al_The_Man]

When dealing with 3 phase, Unless your system is referenced to ground or have a neutral, the reading will be misleading, I would suggest only taking readings across three phase, if you need to.
Al.