Fanuc chuck programming

I have an old Yam lathe with a Fanuc 11T control. I’m using a bar puller with M68 & M69. Everything works fine, but after the end of the program, the foot pedal for the chuck doesn’t function until I push reset. This causes me to lose position and need to rehome before the next cycle. Is there a code to free the chuck after the program so I can just use the foot pedal?


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Clymer said:

I have an old Yam lathe with a Fanuc 11T control. I’m using a bar puller with M68 & M69. Everything works fine, but after the end of the program, the foot pedal for the chuck doesn’t function until I push reset. This causes me to lose position and need to rehome before the next cycle. Is there a code to free the chuck after the program so I can just use the foot pedal?


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Click to expand...

put a dwell after the m68 and after the m69, that may help

Post the exact code you're using for the forum to see. If there isn't a M5 right before you need to hit the foot pedal might try adding one. Kinda sounds like it's not sure the spindle is stopped and won't allow the chuck to open until you reset? You could also instead of using the foot pedal to open the chuck try it with the M code that does so. You'll need the M5 first before the chuck open code.

Brent

The use of M68 and M69 and what ever needs to happen to re-enable the foot control is determined by the machine builder, not Fanuc. Is there a Yam programming or operators manual with your machine?

yardbird said:

Post the exact code you're using for the forum to see. If there isn't a M5 right before you need to hit the foot pedal might try adding one. Kinda sounds like it's not sure the spindle is stopped and won't allow the chuck to open until you reset? You could also instead of using the foot pedal to open the chuck try it with the M code that does so. You'll need the M5 first before the chuck open code.

Brent

Click to expand...

forgot about that on some machines

Vancbiker said:

The use of M68 and M69 and what ever needs to happen to re-enable the foot control is determined by the machine builder, not Fanuc. Is there a Yam programming or operators manual with your machine?

Click to expand...

good to know

Are you sure it is the chuck causing the problem? If I want to run more than one cycle at a time like when using a puller and bar feed compared to running single part slugs I have to use a different M-code at the end of the program. Also if the % character is missing at the end the program it won't rewind to the top unless you hit reset.

Vancbiker said:

The use of M68 and M69 and what ever needs to happen to re-enable the foot control is determined by the machine builder, not Fanuc. Is there a Yam programming or operators manual with your machine?

Click to expand...

Correct, although a lot of machine builders utilizing Fanuc controls use the same M-codes for the same operations leading a lot of people to believe they are specific to the controller and not the machine.

Dualkit said:

Are you sure it is the chuck causing the problem? If I want to run more than one cycle at a time like when using a puller and bar feed compared to running single part slugs I have to use a different M-code at the end of the program. Also if the % character is missing at the end the program it won't rewind to the top unless you hit reset.

Click to expand...

Hello Dualkit,
Its not possible for a program to exist with the % character missing at its end, in the memory of a Fanuc Control. You will note that there is no % character available via the keypad. Accordingly, its not possible to either input, or fail to input this character when creating a program via Finger Cam. When a new program is started by keying "O", a program number and Insert, the % character automatically appears immediately after the Program Number and will continue to appear after all subsequent Inserts of code.

Similar to not being able to Input (Insert) a % character, nor can this character be deleted from the program. Accordingly, there is no scope to inadvertently delete it.

If a program not containing a % character at its end, is Uploaded to the Control from an external device, the transfer will progress without an issue until the end of the file is reached by the External Device, at which point the Control simply waits with the LSK blinking. If you now press Reset at the Control, the program that has been sent to it appears, complete with the % character at its end. Accordingly, its not possible to transfer a program without a % character at its end to Fanuc Control and result in the program in the Control's memory being without the % character at its end.

Depending on how the Comms Software handles the omission of the % character, it will either hang, or simply do what it normally does at the end of a file. In my own software, I look for the % character as the EOF. Therefore, my software simply waits for Esc to be pressed to abort.

Irrespective of whether there is a % character, or not, this character has Zero to do with the program returning to the Start of the Program. This is the function of M02 (M30). These M Codes stops Automatic Operation and the CNC unit is reset. This differs with the machine tool builder. For FS16 Control onward, Bit 5 of Parameter 3404 (M02) or Bit 4 of Parameter 3404 (M30) can be used to disable M02, M30 from returning control to the start of the program.

Regards,

Bill

Dualkit said:

Correct, although a lot of machine builders utilizing Fanuc controls use the same M-codes for the same operations leading a lot of people to believe they are specific to the controller and not the machine.

Click to expand...

Hello Dualkit,
The M Codes you will find mentioned in a Fanuc manual are hardly attributable to Fanuc per se; they are more a convention, used by just about all Control Builders. Further, it actually states in most Fanuc Manuals:
"The correspondence between M codes and functions is up to the machine tool builder".

Regards,

Bill

I should have posted code initially:
First part of program,
change to barpuller;
G00 X0 Z0.1;
M05;
Z-0.1;
M69;
(feed per minute);
G99;
G01 F50.0 Z2.0;
M68;
Z2.5;
M03;
(Feed per rev);
G98;
Rest of the program;
M30;


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Clymer said:

I should have posted code initially:
First part of program,
change to barpuller;
G00 X0 Z0.1;
M05;
Z-0.1;
M69;
(feed per minute);
G99;
G01 F50.0 Z2.0;
M68;
Z2.5;
M03;
(Feed per rev);
G98;
Rest of the program;
M30;


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Click to expand...

Hello Clymer,
M69 and M68 appear to just Open and Close the chuck respectively. Before initially running the program, when the chuck is able to be operated via the Foot Switch, if you were to execute M69 and then M68 via MDI, does the Foot Switch become ineffective?

Clymer said:

Everything works fine, but after the end of the program, the foot pedal for the chuck doesn’t function until I push reset. This causes me to lose position and need to rehome before the next cycle.

Click to expand...

Does your control have Workshift and Tool Geometry Offsets? If so, why would pressing Reset require you to re-home (the axes I assume)? If your program is even just half decent, application of the Tool and Workshift Offsets should be included in the program.

When Posting a program example, you should at least list all of the code for a particular tool and some of the code prior to the M30. Your code example above still has the Forum guessing as to how your Work Coordinate System is set and any other commands that my be playing a part in the Foot Switch becoming ineffective. You don't say as much in your Original Post, but is the program returning to the Start when M30 is executed?

Not always, but in the overwhelming majority of cases, M30 is linked to Reset. Accordingly, M30 should halt Auto Operation and Reset the Control.

Regards,

Bill

It appears your G99 and G98 are swapped? Or at least labeled incorrectly? Most likely a typo.

Brent

Thanks for the replies, I've been tied up and couldn't get back on here. I think I did have the g99/98 mixed up when I typed this. I did't include the rest of the code b/c it seemed irrelevant. If i run a program like this with no m68/69, it runs fine, returns to the start of the program, foot pedal works, no lost position at the end or anything, it just works. I've looked through machine documentation and M68 and M69 are the only M codes it gives regarding the chuck. Just for fun I tried M67 and M70 to see if they might work like a chuck open/close cancel code, but no luck.

Does your control have Workshift and Tool Geometry Offsets? If so, why would pressing Reset require you to re-home (the axes I assume)? If your program is even just half decent, application of the Tool and Workshift Offsets should be included in the program.

Click to expand...

My program is not half decent, lol. The machine has the offesets, but I don't think I use them right. No offsets in the program, except the tool numbers. For years now I've said "I need to read up on how to do that right as soon as I get through this next job..."

Clymer said:

I did't include the rest of the code b/c it seemed irrelevant.

My program is not half decent, lol. The machine has the offesets, but I don't think I use them right. No offsets in the program, except the tool numbers. For years now I've said "I need to read up on how to do that right as soon as I get through this next job..."

Click to expand...

Hello Clymer,
Hence the reason for Posting a more complete program. Drip feeding information to the Forum is just going to have the members guessing and simply drags out any chance of a resolve.

Regards,

Bill

Sounds like it's not getting the chuck confirmation signal from the actuator. You may want to see if the prox switches are functioning correctly.

Try M2 at the end instead of M30. I don't remember the difference, but there is a difference.

R

litlerob1 said:

Try M2 at the end instead of M30. I don't remember the difference, but there is a difference.

R

Click to expand...

Hello Rob,
The difference was more applicable in the days of the Tape Machine and whether the Tape Reader was a Reel to Reel, or just an Endless Loop. M30 was Reset and Rewind, M02 was just Reset. Nowadays, each have the same use, but their execution is settable via parameter. Each can be set to either:

1. automatically search for the head of the program.

2. not search for the head of the program. The head of the program is searched for by the reset and rewind signal.

If the OP were to post the program, or at least the arse end of it, so you can see how repeat and program finish are handled, then there would be a better chance of helping him. As it is, we can go on guessing.

Regards,

Bill

Sorry guys, I'm really not trying hide anything or keep anything out, just trying to keep it simple. This issue doesn't apply to any specific program so most of the code is irrelevant. I can make a simple program such as:

O0001;
M69;
G04 P1000;
M68;
M30;

Foot pedal works fine beforehand.
Run program and the chuck opens, waits, closes, ends and goes back to the top of the program and flashes the yellow light to tell me its done.
If I hit cycle start, it does it again.
If I hit the foot pedal after running the program, I get nothing. If I hit reset, then the foot pedal works again.

Clymer said:

Sorry guys, I'm really not trying hide anything or keep anything out, just trying to keep it simple. This issue doesn't apply to any specific program so most of the code is irrelevant. I can make a simple program such as:

O0001;
M69;
G04 P1000;
M68;
M30;

Foot pedal works fine beforehand.
Run program and the chuck opens, waits, closes, ends and goes back to the top of the program and flashes the yellow light to tell me its done.
If I hit cycle start, it does it again.
If I hit the foot pedal after running the program, I get nothing. If I hit reset, then the foot pedal works again.

Click to expand...

You need to revisit post #4 in this thread.

There is logic written into the YAM ladder logic program that is inhibiting the foot pedal when the chuck function M codes are being used. Reset is releasing that logic thereby allowing the pedal to function again. YAM may have provided a keeprelay in their logic to alter that behavior. You will need to check your YAM documentation to discover your options.

The Fanuc side of the control does not know or care if you have a chuck or faceplate or whatever attached to the spindle.

But his issue is that when he resets the machine, he needs to re home it.