Thread: Okuma MV-5 with an OSP 3000 control questions

Hello gents, got a strange problem on one of these I'm trying to figure out. Problem is that in the program it, intermittently, is hangs up on a Z move. It will just sit there with no alarms. Sometimes after 5 or 10 minutes it will will move reposition for the next move in Z and hang up again with no alarm. Most of the time it will just sit there for until you hit reset.

It does the same thing in any program ran. I can jog all day long, it only does it in auto. There is not much in the way of manuals. Part of an operation manual. A programing manual and a set of electrical schematics.

I've worked with a 5020, 7000 and a UG100 before but never a 3000M ( 82 vintage ). There is a section on self diagnostics but I seem to having difficulty making use of it. It does appear to display as the manual states it should. Any help in that area would be appreciated as far as interpreting it.

It has LDU 600 drives for the axis.

It is running in inch/min so I think that rules out a spindle feedback issue.

The problem only appears to in Z. Sometimes in + sometimes in the -. Sometimes it will run through the program, sometimes it won't make it past the first Z move.

The lack of diagnostics on an intermittent is killing me here.

The one thing that stands out a little is, I was able to pull out of the diagnostics is that there is a .002 in the RDIF on the Z and the next 2 screen show the a .002 difference in the Z position. I seem to recall that the Okumas were a little finicky about a difference between the actual and the position it is supposed to be at. But with no manuals I can not search down that avenue.

Basically, I feel like I'm playing " Whack a Mole " with a Gremlin.

Any help or suggestions at all would be greatly appreciated guys. I joust with it again in the morning.

Thanks in advance,

Dave

No mills with 3000's but some lathes. I'm at home and my manuals are at the shop, but IIRC there's some parameter settings for difference in actual vs commanded position, and if they're set wrong the control will do some crazy stuff. I crashed one of mine once, pretty solidly, and the jar somehow altered those parameters. On the restart, it would try to move and the drive on the moving axis would kick out. Was about to declare it dead and stumbled onto what looked to be some wierd numbers in those parameters, reset them to some reasonable values per the manual, and everything was fine. Probably not your problem, but it proved absolutely that parameters can change in these critters without human intervention.

The operation manual is the one that covers parameters. There's not many of them, but I've never seen their identification and values anywhere but in the op manual.

FWIW, I've never had one of my lathes stop for any reason without throwing an error code.

Oh....just remembered one last thing....have you checked to see if the feed hold light is lit when it stops? On one of mine a while back it did begin stopping an axis for no apparrent reason. Feedhold was energizing itself somehow. Pulled the button out of the panel and saturated it with some cleaner and its been fine since. Didn't feel sticky or otherwise unusual. When that happened it would sit there forever and not do anything, and of course there was no error shown because it really wasnt an error.

Added: Probably not it either since you said it sometimes moves eventually. Once feedhold is engaged, cycle start has to be pushed to clear it.

Metl, yep no feed hold, and just for grins tried cycle start when it stops. It does this in single block and auto.

It does act exactly like it is in feed hold. Z always reached the programed position which is why I was thinking it might be something with the difference I saw in the in the RDIF. Mabye there in the one set of numbers so it does not command ant further feed. And not in the other so it just sits there.

I was thinking that a manual for the LDU 600 drive would explain the settings and maybe give me some things to check.

Keep on posting any thoughts or ideas, it all helps.

Thanks,

Dave

CNCMEK,

Shoot me an email... from an address that can receive attachments in the 3.5MB range... I'll send you an MC-5V/OSP 3000 Op & Maint. manual...

JR@GaMTR.Com

Have you had Gosiger in to look at it. They have a couple of guys who work on the older stuff.

JR - e-mail sent, thanks.

16w,I have spoken with them. They are checking the basement for some info. They have some good techs, Dave is a great guy. They may be in next week.

[ 07-09-2007, 05:36 AM: Message edited by: cncmek ]

Well, an update is due. It's always nice to know what the problem was for future reference.

I was informed on day two of troubleshooting that the Z axis brake had been adjusted. I heard noise when running the Z And they said it was the ball screw, and to be honest it sounded like a bad when rapiding. Was quiet when jogging.

The Okuma distributor came in and looked at the RDIF that I talked about and it was out too far. And way too far out when moving the Z.

They found the Z brake was bad. The brake had been mechanically locked down enough to hold the axis when E-stopped. They backed it off and the machine ran OK. New brake on order.

One would think that I would have gotten an over-current on the Z or that it would have alarmed out during a move with the RDIF being so high. Or that it would never have completed a programed move then just sit there. Per the manual there are alarms that followed the problem but were not displayed and never alarmed out.

Anyways it looks like you just get some weird stuff from time to time and it is a 25 year old machine.

Thanks for the help guys and hopefully this will help someone in the future.

Dave