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Howa Okuma Millac 4H startup - 'Not Ready'

Cooperstock

Aluminum
Joined
Apr 13, 2015
Hello,
I have been doing some searches to see if there was something obvious I am missing on 'Not Ready' condition of the machine, I have yet to find anything as it seems it is a generic condition of the machine. So I will try to include what machine I have, what I have tried and resources easily available.
1. This is the 80's era machine. I purchased it locally about 6 months ago, it was working (actually saw it running) at the shop I purchased it from. I was told he was using the drip feed option to program it although I have yet to find where that connected. The machine has Fanuc 6M - B controls. This machine has the 4 axis option.
I received with the machine the 'Operation Manaul' for the MillAC 4H as well as the 'Operation manual' and 'Service Manual' for the Fanuc 6M-B.
2. What I have looked at (and tried): So when I push 'on' on the Fanuc controls it turns on and once the screen clicks on it displays 'Not Ready' and a 'Ver' number. I do not know if it displays any messages during boot up prior to that screen as the CRT isn't on then. I then push 'Machine ready' button and nothing happens. At this time the machine has 3phase power, I have selected the 200-220 vac input switch in the main input cabinet as I measured the voltage into the machine at 213vac out of the transformer. However I do not have a phase rotation meter, so I do not know which order of wires are needed.
Also, I verified there is air pressure into the machine manual says 5-7kg/cm...I had to convert, so I need ~70-100psi. That at least runs into the regulator, can't say where it goes (or doesn't go) after that.
So at this point the machine has power, has air, the control cabinet fans are running, the CRT is on, and NO other lights are on.

My understanding is that at this point the hydraulic system would need to be started which is what I am assuming the 'Machine ready' button would do. the hydraulic system indicates it is half full of oil. The manual indicated there is not a level sensor.
I checked all of the E-stop buttons (the two I found) and they are out. The one on the controls cabinet I was able to visually check the contacts were moving.

I looked at the alarms in the Fanuc and there was none displayed
I looked at the diagnostics and confirmed that the switches seem to work: i.e. when I change from 'Tape' to 'remote' the bits toggle, when I spin the pulser remote the bits change. When I select an axis and set to 'jog' and press '-' the 'axis jog -' bit toggles.

So at this point I have been trying to figure out where the 'Machine ready' button goes. I do not have a maintenance manual for the MillAC 4H machine so I do not have a wiring diagram that shows where that button is wired to. I looked through the Fanuc manuals to try to locate it, but it doesn't appear to be tied to fanuc controller unless the name is different. There are connection diagrams in the Fanuc maintenance manual, and pages 193 and 194 show the ladder logic for the operators controls (single block, dry run, zero return, manual absolute, cycle start, feed hold...etc) but it does not show any button called 'machine ready'

The MillAC 4h manual says that for start up I 1. turn on the controller and 2. start the hydraulics (which I am assuming is the 'machine ready' button).
I have found nothing labeled 'hydraulics on' and the manual gives no button reference to find on a diagram.

At this point I am going to check the diagnostics to see if any of the axis limit switches are triggered. (in case that affects the e-stop circuit, but keep in mind I have no alarms).
The other thing I am going to start checking are the fuses.

Can anyone provide some more insight into the 'Machine Ready' button? Or any suggestions or pointing out things I have missed or misunderstood.
Thank you,
David
 
Not ready indicates the machine is in emergency stop. You need to investigate the e stop circuit.

As far as start up, can you contact the previous owner? Each machine is a little different. Normally there is a button to power up the control, and another button to power up the servos and hydraulics. Some machines use the same button pushed twice.
 
Thank you, at least I know I should focus on the Estop circuit. It appears for this machine it has the two buttons and then limit switches on the axis.
I did contact the previous owner, apparently his shop went under and he said he had no idea about what to look at to start it, Im guessing he just didn't want to mess with it.
I did try pressing the power button twice for the Fanuc 'on', but it didn't do anything. I tried to hold down with 'Machine Ready' button in case something needed to latch.
I have started trying to trace down where the wires go, fortunately they all have numbers so it is possible, it will just take some time.
It seems limit switches are the next thing to look into.
In the diagnostic screen some signals are identified with a '*' in front of them, I am guessing this means the signal is inverted?
*ESP means 1 = emergency stop is off, 0 = emergency stop is on...?

I did manually engage the hydraulic contactor and it started (I pushed the contactor with the volt meter leads). I also checked the main voltage board and there is 24vdc and 5vdc.

Thanks for the direction
David
 
Make sure that the machine is not on one of the over travel limit switches. The e stop/start up string should go through the limit switches and though some contacts for motor over temp and what not.

If you had a wiring diagram we could surly figure it out.
 
Checking the diagnostics. None of the axis have an over travel flag. The ESP (Estop) flag is set...so i have confirmed it is a problem with the estop...but not from axis over travel. Unfortunately i can not find what other components the estop goes through. I am going to try to jumper the switches to make sure they arnt bad.
I am going to attache a picture of the estop circuit from the manual.
 

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Heres the other reference to the estop.... not very helpful

Not sure what you were trying to post but it didn't show.

I also have an Okuma-Howa Millac, mine's a MC-4VA (vertical not a horizontal). Your estop system has problems, "not ready" is what the Fanuc side says when it's all booted up and done with its POST tests and the rest of the machine hasn't come up. You could get ahold of your local Hartwig (I know there's one in Denver) that can probably give you some manuals and diagrams, god only knows if they will be relevant to your machine (ask me how I know).

If the estop system is anything like the 4VA on yours it makes a big loop between the Estop button on the panel and any other estop buttons, the overtravel switches, a fuse for the estop loop itself and IIRC a couple of breakers and relays. Given the age of the system EVERYTHING needs to be under scrutiny, a diagram will give you a starting point from there you may just have to pull covers and test or bridge switches with alligator clips until you find what is bad, could be as simple as the contacts in one of the estop mushroom switches or the machine ready button, a loose connection, corrosion, a broken wire or a chip cutting in somewhere it shouldn't.
 
Thank you,
I wish i had a real wiring diagram so i could follow the wire numbers. I need to figure out where the 24v starts for the interlock loop. May just be a fuse...
 
So I started down the road of the Estop circuit.
Both estop buttons seem to work. I.e. i disconnected the wires and cycled the buttons to make sure the contacts opened and closed.
I did the same with the 'Machine Ready' button and it did not work. The contacts were black. I disected the switch and cleaned all the contacts (there were three sets). now it cycles every time.
So what it seems is the 28v for the interlock circuit starts at the machine ready button...which is odd. The Estop on the operators panel only has one set of contacts and it connects directly to the 'machine ready' button.
It appears that Estop then goes to the one on the front of the machine as the wire numbers seem to indicate (#31 off of the first Estop, #31 is on the second Estop)
I then started looking for the axis limit switches, I found the panel covering them (I think) but thats as far as I got.

If the Estop system is actually tied to the 'Machine ready' button I don't understand why the machine would every start WITHOUT an estop flag.

GreenBuggy I have a couple of questions for you if you don't mind:
1. Do you push the 'on' button next to the CRT to turn on the Fanuc system? and then a different button to turn on your hydraulics?
2. does your machine start up in the 'ready' state when you push 'on' button, or do you have to push the 'machine ready' button to start your machine?

Oh and I sent an email request to Hartwig, I know today is a holiday so we will see what they have to say.

Thank you!
David
 
The e-stop chain goes through the "machine ready" button because there is a machine start contactor somewhere that is latched by the button.

Do you have an overtravel release button? If you hold the "machine ready" button down, can you jog the axes?

It depends how the machine is set up, but on many machines, the overtravel alarm or flag as you call it, is just for the software limits. It does not indicate the condition of the actual limit switches. In a hardware overtravel, the machine goes into e-stop. You can see in the diagram that the temporary release button bypasses the limit switches while it is pressed.
 
I have not found that switch/button yet...i would assume it would be on the control panel.
Would be nice to have to verify the limit switches are not the problem (or are the problem)
I havent tried jogging the machine....i will see if that does anything.
The reason i didnt use the word 'alarm' is that there is no alarm in the 'alarm' section, but i do see the ESP bit is cleared which is an inverted signal, thats why i called it a flag. The code doesnt seem to think there are errors/alarms/issues, i just cant start the machine. Im guessing hardware loop like you said. Maybe a stuck float switch somewhere. Does air pressure play in the interlock loop? (Usually)
Thanks for the reply
 
So I started down the road of the Estop circuit.
Both estop buttons seem to work. I.e. i disconnected the wires and cycled the buttons to make sure the contacts opened and closed.

Are you checking with a DMM? My experience in industrial troubleshooting has been that physical movement may not mean much if there's crap inside the switch itself.


I did the same with the 'Machine Ready' button and it did not work. The contacts were black. I disected the switch and cleaned all the contacts (there were three sets). now it cycles every time.
So what it seems is the 28v for the interlock circuit starts at the machine ready button...which is odd. The Estop on the operators panel only has one set of contacts and it connects directly to the 'machine ready' button.
It appears that Estop then goes to the one on the front of the machine as the wire numbers seem to indicate (#31 off of the first Estop, #31 is on the second Estop)

My machine is set up similarly, with wire numbers increasing for every additional switch that is crossed.

I then started looking for the axis limit switches, I found the panel covering them (I think) but thats as far as I got.

No idea how the horizontal machines are set up but on my vertical there's a stack of Omron switches on the X, Y and Z axis, that switch assembly is covered by a chip/coolant shield. Only one of the four is actually the overtravel switch, the others are for homing and slowing down the axis as it approaches end of travel. The overtravel is part of the estop chain and first number will likely be the same as the wires running across your estop buttons

If the Estop system is actually tied to the 'Machine ready' button I don't understand why the machine would every start WITHOUT an estop flag.

GreenBuggy I have a couple of questions for you if you don't mind:
1. Do you push the 'on' button next to the CRT to turn on the Fanuc system? and then a different button to turn on your hydraulics?

After switching on the disconnect, the fanuc system is powered on with the switch next to CRT and once the 6M has come up and says "not ready" I press the "machine ready" button which starts up everything else. My understanding is that the hydraulic pump contactor is controlled by the PLC as it shuts down when it is not needed for a tool change or other operation. There are M-codes to start/stop the hydraulic pump for testing. Note that this is for the toolchanger hydraulics and not the spindle oil pump (assuming yours has one) which circulates spindle oil thru the bearings and chiller.

2. does your machine start up in the 'ready' state when you push 'on' button, or do you have to push the 'machine ready' button to start your machine?

Machine does not start up in ready state, "machine ready" button must be pressed every time.
 
Are you checking with a DMM? My experience in industrial troubleshooting has been that physical movement may not mean much if there's crap inside the switch itself.

Thank you, the increasing numbers is good to know.
Yes I used a DMM to check the contacts (on the Estops and machine ready), thats how I learned the 'Machine Ready' switch needed to be cleaned. Prior to cleaning some contacts, while moving, never made contact. After clearing every push made a good connection.
I will look into the limit switches next. and hopefully Hartwig responds too.
 
Update:
Contacted Hartwig, the guy (Brian) was nice and indicated he was going to see what he could find (Feb 23rd). I haven't heard back from him yet, I really hope he is able to come up with some sort of machine assembly manual that shows a wiring diagram for the machine with wire numbers...but my hopes may be grand.
My plan (once I have some time) is to jump the initial connection which will put the 28VDC onto the Estop circuit at the 'machine ready' button and then attempt to trace the signal through the connections.
I still need to remove the cover for the limit switches in the machining compartment and inspect those.
If anyone comes across this thread and has some wiring diagrams/schematics or other information, please let me know.
I am still confused about the 'limit switch bypass switch', it seems it would be necessary in order to move the machine off the limits since supposedly they all feed the estop circuit. But I am unable to find any such switch on the machine.
 
Here are a couple pictures of the machine controller. I know they aren't very high resolution, if other pictures might help, let me know
toolchanger.jpgmachineside.jpgFanuc6M.jpg
 
I have alot of experience with the 6MB, but not on an Okuma. I know the Okumas usually used thier own PLC's to interface with Fanuc and the Kitamura and Mori 6MB's I have use the Fanuc PLC's.


Not ready means not ready. Something isn't happy and not letting the control come up. On my machines with Fanuc PLC's you can look at a section of the PC parameters like # 240-260 and if there's a 1 anywhere in there that's your problem. There are LED's on boards all over inside the cabinets. If you have any red LED's lit figure out why.

Things that can crap on your machine readiness-

Lube level, spindle chiller, servo or spindle drives not ready, any circuit breaker/contactor heater tripped anywhere in the machine, bad fuses, bad board connections.

Does hydraulic pressure build when you push in contactor? If phase rotation is or was wrong that can be related.

Do you have 4,000,447 ice cube relays in the machine? Take a few minutes to wiggle and re-seat all of them.

Buy some contact cleaner like De-Ox and pull the daughter boards off the main board and hose the connectors.

The 6MB does not have batteries. You can't hurt the boards removing them carefully.
 
Update:
Contacted Hartwig, the guy (Brian) was nice and indicated he was going to see what he could find (Feb 23rd). I haven't heard back from him yet, I really hope he is able to come up with some sort of machine assembly manual that shows a wiring diagram for the machine with wire numbers...but my hopes may be grand.

My experience with Hartwig is that if you are unable to go into an office and talk to someone you have to ride their ass to get documentation. YMMV.

My plan (once I have some time) is to jump the initial connection which will put the 28VDC onto the Estop circuit at the 'machine ready' button and then attempt to trace the signal through the connections.

That "initial connection" should be the the "machine ready" button on the main control panel. I don't know whether or not that will give you useful information, if you put an ohm meter on the switches with power off or volt meter on the switch contacts with power jumped that would tell you where your open switch is.

I still need to remove the cover for the limit switches in the machining compartment and inspect those.
If anyone comes across this thread and has some wiring diagrams/schematics or other information, please let me know.

You can figure out which switch is which by looking at the numbers that attach to each switch, and the positions of the movable tabs which trigger the switches. The Estop switch should have the same starting number as the rest of the estop components, on my 4VA they are all 2xx numbers for the estop chain.

I am still confused about the 'limit switch bypass switch', it seems it would be necessary in order to move the machine off the limits since supposedly they all feed the estop circuit. But I am unable to find any such switch on the machine.

When I first got my Millac I was advised of its existence but couldn't find one. It may have been an option but I think if you hold the "machine ready" button down you can move axis off limit switches as long as nothing else is holding up the estop chain.

On my machine the low lube switch will prevent the estop chain from latching, that would be first thing I'd check.
 
Another thing that will cause what you have is the cabinet door switches. Check them over well/disable them.
 
My experience with Hartwig is that if you are unable to go into an office and talk to someone you have to ride their ass to get documentation. YMMV.



That "initial connection" should be the the "machine ready" button on the main control panel. I don't know whether or not that will give you useful information, if you put an ohm meter on the switches with power off or volt meter on the switch contacts with power jumped that would tell you where your open switch is.



You can figure out which switch is which by looking at the numbers that attach to each switch, and the positions of the movable tabs which trigger the switches. The Estop switch should have the same starting number as the rest of the estop components, on my 4VA they are all 2xx numbers for the estop chain.



When I first got my Millac I was advised of its existence but couldn't find one. It may have been an option but I think if you hold the "machine ready" button down you can move axis off limit switches as long as nothing else is holding up the estop chain.

On my machine the low lube switch will prevent the estop chain from latching, that would be first thing I'd check.

Thank you! (Belated)
I need to check the lube. Didnt know there was a switch there.
Im just getting back to setting up this machine...have been busy working lol
 








 
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