Need Help!- ML20 E STOP PROBLEM

[GMOORE1]

I have a 1999 ML20 that as of yesterday started giving me "450 e stop spindle pump not functingwhile spindle is turning". I pulled the headstock cover and pump is working fine. I could not determine how the control senses
the faulty pump. Thinking maybe there is a faulty sensor.
Anybody familiar with this setup.

Gary

[philserveng]

probably, there is a flow switch giving an input to the PLC. check the input, find the address in the electrical schematics (X12.6 for example). also, check if there is an in-line filter before the switch, if blocked this could give you a fault. also, have you got enough oil in the system?

[GMOORE1]

Originally Posted by philserveng probably, there is a flow switch giving an input to the PLC. check the input, find the address in the electrical schematics (X12.6 for example). also, check if there is an in-line filter before the switch, if blocked this could give you a fault. also, have you got enough oil in the system?

Hi,
The mechanical pump which is driven by the input shaft is very visible. The pickup filter is 8" from the pump and the outlet from the pump goes staight to the the manifold then to each oil point. There is no inline filter or sensor visible here. The only spot I cannot see is the back of the pump which is bolted thru the headstock casting and covered by the splashguard behind the chuck. I cannot find a single wire without a termination spot that could go to this spot. It shutsdown after about 5 minuts then within seconds after that.
gary

[jpawelk]

That vintage of the ML20 did not have a pressure switch for the headstock oil pump. I believe that there may be a short somewhere giving the control that input.

[bborb]

Is there a switch on the splashgaurd? Is it working properly?

[Wcarmn]

check for a short in wiring....

[GMOORE1]

Yep, confirmed this morning by Milltronics no pressure switch on this model. Now I get to track down an E stop display that has no hardware to back it up. Milltronics suggested check the circuits that would normally except this sensor. Machine finally started running last night for about 2 hours and now this morning back to same problem. Anybody ever experienced this before?

[philserveng]

Let's face one fact.........you have an alarm stating there is a fault from the spindle lub pump, how does the PLC know this? Answer, it must have an input from somewhere.

My second suggestion is to check the lub pump motor overload, if it is set for "auto-reset" then if the motor gets hot or overloaded then it is possible for the machine to behave the way it does. i.e; on a while then trip off, cools down.........then on again. The overload may also have an auxillary relay giving the PLC input, hence the alarm.

It could be the pump is tight due to bearings or residue in the oil, or the oil viscosity is too high (too thick). Put a clamp meter on the motor windings and check current, it might be ok and if so, the overload needs replacing.

[GMOORE1]

It ran all afternoon without a problem. This morning however it was shutting down over and over until I shut the whole system down and restarted. Then it would run awhile. I unplugged and plugged back in all the input and output plugs going in to the card cage. Now its running ok, but for how long? Like I said in an earlier post the spindle pump is mechanicaly driven not by a electric motor. No inline sensor or any electrical at all. There where some models with an inline pressure switch. So I see why there is an e stop for this in the computer system. I just don't know what possibly could be setting this off.
Gary

[philserveng]

does your electrical schematic show an input for this signal, I know you don't have it, but it is possible the fault input is "active". what I mean is there may be a link wire from 24vdc to this input. this link wire could be loose causing the problem intermittently due to vibration.

it may also be possilble the input connector to the NC rack has a bad contact or a cracked solder bridge for the input. get an experienced electrician to check out this circuit and if he can to replace the link wire. ask the machine service department which terminal numbers need be tested.

is there a PLC input for this signal ?, if so I think it should be at "1" all the time for the fault to stay "low" (off)

this advise is based on the pump being purely a mechanical drive.

[GMOORE1]

Milltronics faxed me an older version of an schematic that showed a spindle pressure switch that ran into the Home input on the #7 pin (My schematic that came with the machine showed no pressure switch of any sort or place for one). Which of course on my machine the #7 pin at the Home input is empty. I am gonna try to follow up tomorrow and get an updated version to see if there any other input position possible. I thought the home position was an odd choice for an lube pressure switch, but once you get into the card cage it starts getting way over my head. I will check the on the link wire like you suggested. I have been also starting to suspect the rack with an solder issue. I didn't run the machine today, but I have alot to run this weekend and of course if it's going down it will be then.

I sure appreciate the input!

[GMOORE1]

Finally sent in the card cage control. It was a bad interface board. Milltronics recieved my control one day and was shipping it back with new board by the end of next . These folks sincerly want to solve your problems. I bought my machine used and it is a 1999 model. Getting this kind of service I can't imagine how they react to folks with service problems with much larger new machines. They sure have my future new machine business.
Actually considering one of thier vertical mills with the new MILLSLIDE option. I would be using mostly manuel, but do lot of drill and tap hole patterns and long keyways. My business is mostly lathe work ( rollers) so I can't rationalize a stand alone cnc mill. I was wondering if anybody has opinion of this machine.
Thanks again for the help on the board.