Fanuc OI MC control Tool change height

[Duck Waddell]

I have a Kent JM 450 machining Center with a Fanuc OI MC control. There was a crash on tool change at some point. I wasnt there so I dont know details. The issue is the carousell grabs the tool in the spindle fine but the head will not come up far enough when the carousell goes back in so it crashes. How can you change how far it goes up?

Thanks

 

[angelw]

I have a Kent JM 450 machining Center with a Fanuc OI MC control. There was a crash on tool change at some point. I wasnt there so I dont know details. The issue is the carousell grabs the tool in the spindle fine but the head will not come up far enough when the carousell goes back in so it crashes. How can you change how far it goes up?

Thanks

Hello Duck Waddell,
When you say "when the carousel goes back in so it crashes", are you referring to when the new tool is being brought into place to be loaded into the spindle? If the head is not moving up far enough, there should be an issue both when moving the existing spindle tool from the spindle back to the park position for the carousel and when moving the new tool from the carousel park position to the spindle load position.

It depends on how the machine tool builder arranged the tool change system, either using a Tool Change Macro in conjunction with the PMC, or totally using only the PMC. It's more common for a Tool Change Macro to be involved, therefore, it would be a help, to be able to help you, if you were to Post a copy of the Tool Change Macro, if one exists.

If a Tool Change Macro is used, it's common on machines that use a carousel type magazine and where the Z axis moved up and down during the tool change process, is for the two height positions of the spindle to be acquired using the First and Second Reference Return Commands; G28 and G30 respectively. This can be determined by viewing the Tool Change Macro.

Being a Carousel Type Tool Changer and therefore, not able to pre-stage the next tool, the Tool Change Macro can be called either by a "T" code only, or via M06. If the Tool Change is invoked via M06, look at parameters 6080 to 6089 inclusive for the registration of the number "6"; these parameters relate respectively to program numbers O9020 to O9029 inclusive. If the Tool Change is invoked with just a "T" code, the Tool Change Program will be O9000. To further confirm that the Tool Change Macro is being called with a "T" code, parameter bit 6001.5 will be set to "1".

For further help, find out if a Tool Change Macro is being used and Post a copy of it here for the Forum to view.

Regards,

Bill

 

[Duck Waddell]

Hello Duck Waddell,
When you say "when the carousel goes back in so it crashes", are you referring to when the new tool is being brought into place to be loaded into the spindle? If the head is not moving up far enough, there should be an issue both when moving the existing spindle tool from the spindle back to the park position for the carousel and when moving the new tool from the carousel park position to the spindle load position.

It depends on how the machine tool builder arranged the tool change system, either using a Tool Change Macro in conjunction with the PMC, or totally using only the PMC. It's more common for a Tool Change Macro to be involved, therefore, it would be a help, to be able to help you, if you were to Post a copy of the Tool Change Macro, if one exists.

If a Tool Change Macro is used, it's common on machines that use a carousel type magazine and where the Z axis moved up and down during the tool change process, is for the two height positions of the spindle to be acquired using the First and Second Reference Return Commands; G28 and G30 respectively. This can be determined by viewing the Tool Change Macro.

Being a Carousel Type Tool Changer and therefore, not able to pre-stage the next tool, the Tool Change Macro can be called either by a "T" code only, or via M06. If the Tool Change is invoked via M06, look at parameters 6080 to 6089 inclusive for the registration of the number "6"; these parameters relate respectively to program numbers O9020 to O9029 inclusive. If the Tool Change is invoked with just a "T" code, the Tool Change Program will be O9000. To further confirm that the Tool Change Macro is being called with a "T" code, parameter bit 6001.5 will be set to "1".

For further help, find out if a Tool Change Macro is being used and Post a copy of it here for the Forum to view.

Regards,

Bill

Thanks Bill, The issue is when the carousell returns after it grabs the tool in the spindle the head will not go high enough to clear the tool. I have no way to post copies of macros as this machine is in a federal prison and I cant have a phone or computer for obvious reasons. I have to do as much homework as I can before I go to work on it. I can print out your replay and bring it with me so this will help. Thanks

 

[angelw]

Thanks Bill, The issue is when the carousell returns after it grabs the tool in the spindle the head will not go high enough to clear the tool. I have no way to post copies of macros as this machine is in a federal prison and I cant have a phone or computer for obvious reasons. I have to do as much homework as I can before I go to work on it. I can print out your replay and bring it with me so this will help. Thanks

Hello Duck Waddell,
With this type of tool changer, where the Z Axis raises the head stock to clear the spindle of the tool, G30 (second Reference Return Position) is used. Its also common for this elevated Z axis (a considerable distance above the normal Reference Return Position), to be set as a forbidden zone under normal conditions and only made accessible during the Tool Change Operation; this is commonly achieved by a communication with the PMC via a Macro Program.

You can determine how far above the First Reference Return position the Z Axis must go to during the Tool Change, by taking a measurement from the table to the end of the Pull Stud of a tool in the Carousal and then moving the Z Axis to the same distance plus some above the table. The value that is shown in Z of the Machine Coordinate Position Display will be the value that would then be registered in the parameter for the Z Second Reference Return Position (G30). However, as its likely that this position above the First Reference Return (G28) will be a forbidden zone, it will be unlikely that you will be able to move the Z Axis there via the Hand Wheel. It will be very probable that there is a code in the Tool Change Macro that when executed, allows the Z Axis to move into that normally forbidden area.

You really need to view the Tool Change Macro and Post it here to get more help. The Tool Change Macro wont be a very long program and could be easily copied down long hand. There is also often a copy of the Tool Change Macro in one of the books that came with the machine.

Regards,

Bill

 

[Duck Waddell]

Thanks Bill. I think I should give more of a back story as to how this started. The battery on the Fanuc died. The machine owner had to reset the home positions for each axis. When they were done and tried to do a tool change the carousel crashed in the side of the head because the head didn't come up high enough. Thats when I got a call. I found out if you change Parameter 1241 number that would change the Z height at tool change. I changed the number to 95500 and the head went to the correct height to do the tool change. The problem is it didn’t come up high enough for the carousel to clear the tool it put away to index the carousel so it crashed the carousel.
That said to you think the initial issue is the Z axis is not homing to the correct height therefore throwing off the tool change height? Should I start by changing parameter 1241 back to the number it was?

Thanks

 

[angelw]

Thanks Bill. I think I should give more of a back story as to how this started. The battery on the Fanuc died. The machine owner had to reset the home positions for each axis. When they were done and tried to do a tool change the carousel crashed in the side of the head because the head didn't come up high enough. Thats when I got a call. I found out if you change Parameter 1241 number that would change the Z height at tool change. I changed the number to 95500 and the head went to the correct height to do the tool change. The problem is it didn’t come up high enough for the carousel to clear the tool it put away to index the carousel so it crashed the carousel.
That said to you think the initial issue is the Z axis is not homing to the correct height therefore throwing off the tool change height? Should I start by changing parameter 1241 back to the number it was?

Thanks

Duck Waddel,
The Tool Change for any Fanuc Controlled machine can be either completely carried out by the PMC, or a combination of PMC and a Macro Program; its entirely up to the MTB.

If the Backup battery died, the parameters and programs would have been lost. That being the case, if a Tool Change Macro was being used in the Tool Change process then its a wonder that the Tool Change works at all. Accordingly, it may be a case that the PMC carries out the whole tool change.

If is far more common for there to be joint effort between a Tool Change Macro and the PMC, for your type of Tool Change Magazine, but that is not to say that the value for the 2nd Z Home position isn't being used by the PMC, if the PMC is acting alone. Please describe the complete Tool Change Process so that we are on the same page. In most cases with a carousal magazine type tool changer the sequence is as follows:

1. The spindle orientates to the Tool Change Position (M19)

2. If there is a tool in the spindle, the empty magazine tool grip will grip the Spindle Tool by the Carousal moving towards the Spindle. The Z Axis will normally be at the Reference Return Position (Z Home - G28)

3. The Draw Bar pulling the Tool Holder tight in the Spindle will release its grip on the Pull Stud.

4. Z axis will move in a Positive Direction sufficient to clear the Spindle Tool and its Pull Stud (2nd Reference Return Position - G30).

5. The Carousal will retract to it's home position and index the new tool to the Tool Change Ready Position/

6. The Carousal will advance towards the Spindle to place the new toll under the Spindle.

7. The Z axis will move in a Negative Direction, back to the Z Reference Return Position (G28).

8. The Draw bar will grip the Pull Stud and pull the tool holder tight in the Spindle.

9. The Carousal will retract to its Home Position.

Try and describe the current action of the Tool Changer in term as above and advise at which step the process fails. If you do an actual test of the tool change process, do so without a tool to avoid a crash.

You really have to supply more and accurate information. Like, do you know if a Tool Change Macro is being used. This can normally be determined by viewing the parameters that are set to call a Macro Program via an M or a T code. However, if the battery that backs up the parameters died, the setting in these parameters will have been lost. If you have all the books that came with the machine, in the majority of cases, a copy of any tool change Macro will be included.

If the control uses a Tool Change Macro and you can list it here, it will be fairly simple to get you back on track.

Regards,

Bill

 

[GENERALDISARRAY]

I think they just lost the servo bat. So far.

I would put any parameters back to what they were and do the Z axis origin restoration correctly. Then your G28 and G30 will be correct.Like Bill says.

And before they have more heartache, change the control batt with the control on.

 

[Duck Waddell]

The main issue is step 4 when the Z moves in the positive direction it doesn't go high enough to clear the tool. I will have the end user look for the M or T code and let you know.

There is a secondary issue I haven't mentioned that really doesn't have anything to do with Fanuc. The drawbar uses an air over oil cylinder to release the drawbar. The cylinder is very slow. It takes about 3 seconds if you press the tool out button. They have over 100 psi at the regulator. I don't see any flow controls to adjust this. I have seen these cylinders leak air into the oil reservoir making bubbles but this one is not doing that. I don't see anything that would cause this. I guess the unit could be bad.
Thanks for the help on this. It seems like technical help is hard to come by for any of these MTB.