[nlh]

Hello,

I am trying to help a friend fix his Okuma MC-5VA mill. It has a toolchanger issue. When machine is first started up toolchanges work properly but as time goes on the toolchanger arm will hang mid way, sometimes it will grasp the tools and hang. He can succesfully complete ~2-3 toolchanges before this happens. Currently he is just running it as a 1 tool machine or if he needs to change tools, he does so by hand which is not as easy as it sounds because of the heavy 50 taper holders.
The machine is a 1984 model w/ OSP5000M green screen control. Can someone point me in some direction on this? I would really like to help him out but don't know anything about the machine. First guess is maybe a limit switch but the fact that it works only while the machine is cold makes me wonder if there is some air or hydraulic adjustment that needs to be made?


Thanks

[theokumaguy]

They implemented a very useful tool on the mills that "might" be there on the 5000M's, called Machine Diagnosis. If you hit Extend once then hit Machine Diagnosis while it's hanging up it will spell out what the machine is waiting for.

Does this always hang up in the same spot in the tool change, IE right as the tools are gripped? Or does it happen in many positions, arm half way down, arm rotating around etc?

Given the information you've mentioned, I will assume that the machine only hangs up in the tool gripping position. There are a few items that happen at this point:
The arm is pushed all the way into the 60 degree position around the tool (limit switch confirmed)
The arm is pushed up or down by the position of the tools and the hydraulic force of the arm rotation solenoid/gear rack (limit switch confirmed)
The tool is supposed to unclamp (if arm is up and arm is confirmed at 60 degrees)

So the questions are, What does Machine Diagnosis say? What ATC sequence number is displayed on the sequence readout below the CRT? Does the arm make it all the way around the tool? Does it look like it's gripped the tool fully? Is it hanging up on the drive dog, on the tool, or anything else? Does the arm appear to move up or down as it wraps around the tool? Does the arm wrap completely on the tool then just sit there?

Also, usually if you allow the machine to sit in the "stopped" condition for 5 or so minutes, it will alarm out with an "ATC System Condition Failure XXXXX" alarm message, what is that alarm number and code? This might be helpful if none of the others above help us figure this one out.

[nlh]

Thanks Okumaguy,

I will print this out when I approach the machine again and make a checklist. I have never witnessed the problem first hand, only had it described to me, which I passed on to whomever could give me things to check. Once I actually look at the machine and see the problem first hand, it could be different. I will probably be able to get to the machine in another week and half. I will get back to you with what I find.

Nate