Fanuc Tool change strangness

[ARB]

Sharp with Fanuc OiMC. I have one program that runs with 4 tools.

I have started to get a stoppage at the last tool change. This only happens once in a while.

The program stops at the tool change line
T8M6

The cycle start light stays lit and the machine stays in cycle.

This of course is intermittent.
I have other parts that run with as many tool changes that run just fine.

This is always from tool 5 to tool 8.


I solved this by ditching the tool change at the end of the program.


What gives?

Any ideas?

[barbter]

ARB,
It could be a timer issue (keep relay)?
We hade a toolchange issue where it ignored the preselect call and just changed to what was waiting (the previous tool) instead. Luckily not too messy...
Are you calling preselect?
Is your machine random/shortest path or T1 pot 1, T2 pot 2 etc?

[ARB]

This machine is an umbrella style. No pre select. Just a tool assigned to a pot.

I will take a peak into the keep relays.

For additional information. This program with this tool set has run thousands of cycles in the last year and only recently learned this new trick. The wierd thing is that is only this toolchange in this program that gives trouble.

[spock]

Arb, I have had some issues with tool change, I think I posted most of my "discoveries" in this thread: http://www.cnczone.com/forums/showthread.php?t=47916

It is a little long, dont know if it will fix anything but might give you some insight into your problem (which dont make no sense either).

[Curt B]

The machine wants to know that it is oriented and in position for ATC to take place so I would guess one of those sensors is on the borderline. Have you checked that the in position lamps are on when it hangs up? Try adding an M19 on the line before the toolchange and see if it will hang up there. Maybe it’s “confused” and a T0 before the last tool or an M33 to clear all tools may change its behavior.

[Ox]

You have a listing for your Keeps?

Boy tha'd be helpfull! Seems they are trying to guard mine.



-----------------

Think Snow Eh!
Ox

[ARB]

Thanks for the ideas guys. I have some things to look at now.

Spock, I can't say as I can relate it to the rapid thing because I am running it WFO.

I will be looking into the orient switch.

The part that is very puzzling to me is that it is only this program and this tool change.

I think I will right a test program to do some tool change sequencing to see if I can get it to happen on other combination.

Right now I need to finish getting the parts out the door.

[ARB]

Got me by the short hairs. I let it run a test program of tool changes for over an hour without a hickup.

[Mud]

Are you doing the toolchanges in the same sequence as in the program?

Can you just run that program without material and with the coolant off?

[Tonytn36]

Might it be that there is an offset that is not getting canceled in this particular program/tool change situation that results in a Z movement that would be illegal, such as a Z+ over travel if it were to go to change. The control may not recognize this with an actual error (depending on who wrote the ladder), but may just hang.

[ARB]

Originally Posted by Mud

Are you doing the toolchanges in the same sequence as in the program?

Can you just run that program without material and with the coolant off?

Mostly. I am doing the change that is causing the hang up.

There may be somthing to the offsets.

I think I will add some magic to the code to try and make this problem go away.

Nothing like trying to get rid of an intermittent problem.

[stevo1]

If it only happens in that program I would have to agree with Tony that it might have something to do with the program/cancelation. Can you post the program you have a problem with?

I know you’re on a mill but some time back we use to have the exact same problem with our tool changer on our VTL. It ended up being that there was a value in the wear offset. Guys would make an adjustment by .001 or .002 to dial the part in and then forget to clear it out. For some reason the machine did not like that when tool changing. The door would open and it would just sit there. No alarm no nothing.

Stevo

[spock]

"Spock, I can't say as I can relate it to the rapid thing because I am running it WFO."

Dont know if it was clear in the thread I mentioned, but my machine was "hanging" on the tool change (same symptoms as yours) because it had "lost" the signal that populated the ladder right after the previous toolchange (the signal that told the machine the rapid traverse rate). The previous tool had changed, done its work, then hung up at tool change position. The dwell added to the toolchange macro gave it the needed time to get the signal.
Only difference was, mine was sometimes a random event, like every few months, sometimes every toolchange. Has your Sharp ever took off at 100% rapid even when the over ride was lower? Just curious, as you seem to know what you are doing, from a programming point of view, so I am thinking maybe something other than something in your programming.

[ARB]

I can't say as I have ever had it rapid at something other than what I wanted. I will get the code posted later on tonight for all to view.

I think I will also go into the macro and add a touch of dwell. Although that goes against the grain in my book. I am always looking to get all the time out I can. I hate that the tool change macro sends the z all the way to home then comes down to tool change height. To me that is a waste of time. I have been tempted to change that but don't want some unforseen event to happen that would result in poop in my pants.

[ARB]

Well, here is the code for this program. The last T8M6 is where it hangs up. To solve this I took out the last tool change and let it put the T8 in at the beginning and it works.


%
O1779(xyz-1776 MILL-DRILL-TAP)
(C3,D11)
(3/8/09)
(T8 3 INCH FACE)
(T7 SPOT)
(T6 9/32 DRILL)
(T5 5/16-18)
(.25 HOLE IS 0,0)
(Z ZERO IS 1 INCH ABOVE TOP OF TUBE )
G90
G10G90L2P1X-11.739Y-10.187Z-13.11
G52X0
T8M06
M8
M36
G00G90G54X2.4Y3.5S3000M3
G43Z1.H8M08
Z.005
G01Y-.35F85.
X-2.4
Y.35
X1.75Y.9
S6000
Z0
G2J-.9F120.
G0Z.01
X-1.75Y.9
G1Z0
G2J-.9
G0Z.1M9
M5
T7M06
M8
G52X-1.75
G00G90G54X-1.19Y1.19S8000M03
G43Z0.05H7M08
G81Z-.17R.05F80.
Y-1.19
X1.19
Y1.19
G52X1.75
X-1.19Y1.19
Y-1.19
X1.19
Y1.19
G80
M9
T6M06
M8
G00G90G54X1.19Y1.19S10000M03
G43Z0.05H6M08
G4X1.5
G81Z-0.8R.05F95.
Y-1.19
X-1.19
Y1.19
G52X-1.75
X1.19Y1.19
Y-1.19
X-1.19
Y1.19
G80
M37
M9
T5M06
G00G90G54X-1.19Y1.19S1440M3
G43Z0.1H5M08
M29S1440
G84Z-0.95R0.1F80.
Y-1.19
X1.19
Y1.19
G52X1.75
X-1.19Y1.19
Y-1.19
X1.19
Y1.19
G80
G0Z2.M9
G52X0
G00G90X0
G53Y0 Z0
T8M6
G91G28Z0
G90
M30
%

[stevo1]

I could be way off base here but I will give it a shot.

First thing to try would be to remove the G53Y0Z0 before the tool change. I see that you don’t have it before any of the other tool changes so I ass u me that this code is not needed for positioning for the tool change. I use to have issues with G53 but I was using G28 also and it was canceling my offsets and causing problems when positing directly after.

Another shot in the dark is the G28 line directly after the tool change. It should not matter but if the control is reading ahead it may not like the reference directly after.

That’s my .02c

Stevo

[spock]

Arb, my code looks like this for my Oi-mc:

%
O1111(TALL PIN)
G20G40G49G54G80G90G98
T1M6
M13S4444
G0X0Y0
G0Z1.5G43H1
G99 G81 Z-.06 R.1 F3
G80
M9
G91G28Z0.0
M1(or m30)

[Seekins]

I had a simular issue with my Mori last year. Problem was it was random and tough to find. It ended up being a loose tool pot and being a random tool changer.....It got fun figuring that one out..

maybe it will help or not?

[Mickey_D]

I have had something similar happen on certain tools, and all of them had coolant through pull studs. When I would take those tools out of rotation, the problem would go away. Use them and it would randomly come back. My machine is an early model without the extra air tank on the back (hmm, I wonder why they added that?), and it is sensitive to low air pressure on tool changes, and a hollow stud while it is ejecting a tool is sometimes enough to hang the change.

[ARB]

Originally Posted by Mickey_D

I have had something similar happen on certain tools, and all of them had coolant through pull studs. When I would take those tools out of rotation, the problem would go away. Use them and it would randomly come back. My machine is an early model without the extra air tank on the back (hmm, I wonder why they added that?), and it is sensitive to low air pressure on tool changes, and a hollow stud while it is ejecting a tool is sometimes enough to hang the change.

I had that suspicion. For giggles i cranked my Reg up but alas the problem prevailed. I think I will check on the stud though. I know that I do have some coolant through studs in the mix. It is worth a shot.
I just put in the sister job to this one. It has 3 tools and the program is nearly identical. Maybe I can find something.

Thanks for the ideas guys. I will give them all a shot.