Fanuc 6M repair?

[joe m]

We have a Hitachi Seiki VA40 with a Fanuc 6M. Every once in a while, or all the time, the machine will pause in the middle of a program. Apparently waiting for the signal that it finished the last command. Mori Seiki and Fanuc have been very helpful over the phone but haven't been able to find the source of the problem. Dose anyone know of someone experienced in my area that could diagnose and fix this problem. The machine is located just north of Fort Wayne Indiana.

[Guest]

this is a real shot in the dark but ran into very similar behavior on a fanuc and found it to be the feed hold button.

hope its that simple for ya

doug

[Philcott]

Joe,

 

You haven't stated where your area is. Is this happening at a consistant point in the program like cuhck open or close, tailstock forward or reverse? If so you could have a faulty positioning switch that is not sending a signal.

 

Phil

[joe m]

Don't think it will be that easy, Fanuc thought of that too. When it stops the green cycle start light stays on, and pushing start dosn't do anything.

[joe m]

Phil,

Dosn't seem to be any pattern as when it dose it. Although it maybe when M codes are commanded, M19, M30, M03, M98, etc.

 

The machine is located just north of Fort Wayne Indiana.

[Brendan P]

Your machine is prolly a 1984 or 1985.

Jus curious,does it use work offset or G92?

 

The guys in my area Mass. that know the fanuc/Hitachi's is Boston machine in Peabody mass.

 

We have some of these old Hitachi clunkers and it is very funny how just as the heat and humidity came,the machines started to act up!!

[?Mark]

Another loooong shot in the dark...

Any lightning strikes recently?

Had this problem with machine going "postal" (yasnac control) after one of the ligtning strikes we have quite often here...

New comm board fixed the problem.

It'll only happen if you leave rs232 cable connected to the cnc at all times which we don't do anymore

 

Mark

[George_Gerhard]

If the cycle start light stays on STL is commanded and the nc has not issued a FIN or finish signal. When an M code is executed something has to happen. Execute all the m codes through that program one at a time in MDI and see which one fails. Perhaps it is a simple sensor or limit switch adjustment.

Do you have a copy of the ladder logic?

This will help you find what has to answer back the specific m code that is failing

 

good luck

George

[joe m]

Machine is a 1981 and has G54-G59 option. No lighting strikes that I know of.

 

"We have some of these old Hitachi clunkers and it is very funny how just as the heat and humidity came,the machines started to act up!!"

 

That is what I'm thinking, one of these cards is acting up becouse it didn't like move and is just showing it's age.

[JG]

Just a guess, it never happens during a rapid only feed moves, maybe a drive adjustment.

 

Jg

[chris m]

Joe

 

We had a problem with a Yasnac 2000GII of this age and it was an I/O board that was going away. The sort-term fix was to open the control cabinet in back and setup a box fan blowing on the boards. It might be worth a shot...

 

C

[John_Carpenter]

Hi,

 

Mori Seiki Mid-American Sales handles service on the Hitachi's in Fort Wayne area.

 

9587 E. 131st St.

Fishers, IN 46038

Phone: 317-577-3723

Fax: 317-577-8246

 

Regards,

 

John

[Lee.]

Joe,

 

are you drip feeding?

[joe m]

No, not drip feeding. Running from memory or MDI commands. We don't have the DNC set up yet.

[TimHollis]

quote:

---

joe m

We don't have the DNC set up yet.

---

I see the Yet....

How long do you have the machine?

And take the time to give as much detail as possible, especially the actions you have already tried.

 

Tim H.

[joe m]

We have had the machine for a week. The dealer claims the machine ran fine for them.

When running the machine from memory, it will sometimes run fine for a couple hours. Then it will just stop, green cycle start light stays on and no errors are displayed. If you let it sit, 30 secounds to 30 minutes it will start up agin. It seems to be M cammands that do it the most. So far all we have tried is cleaning the cards, and the magnetic switch for spendle orentation.

[chris m]

Sounds more and more like our Yasnac prob; give the fan a shot...

[Lee.]

It could be the wiring to your servo.

 

Sounds to me like your not getting a feedback for position.

 

When you moved the machine the wire could have been stressed.

 

Try This.

 

The servo signal wire that usually runs through the moving wiring harness. Take it out of the harness and string it up somewhere safe.

 

Try that.

 

If it works, replace the wire.

 

HTH

[joe m]

Do the magnetic switches for spindle orientation ware out? It seems to hunt for orientation at tool change.

Also if anyone has one of these they would part out we would like BT tool change fingers, or trade our CAT fingers for your BT.