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.

[Mickey_D]

I had mine come back again this week. I used a couple of tool holders that I had not used in a while and had a little bit of Boeshield on them. I always wipe them down with a clean rag and then with my hand to check for burrs, and they did not feel funny or sticky before I loaded them in. It started randomly sticking on the change again just like it did with the hollow studs. I figured out what was wrong when I grabbed another toolholder that was really coated so I pulled and cleaned them all and the spindle bore too and now it is running flawlessly again.

[ARB]

Hmm. Wouldn't you know. I ran another couple hundred of these parts without a hitch.

I guess I will roll with if for now.

[ARB]

It's back.

Today with a different tool combination but always with the change from 3 to 4 and not every cycle.

I think I will look for the spindle orient switch. This sounds like a likely culprit for this.

[repairguy]

Maybe I missed something in an earlier post, but I didn't see any info as to where in the toolchange it fails. Does it do anything or does it stop without starting the toolchange sequence. Lots of things to check, all depending on where it fails in the cycle.

Dan

[ARB]

Originally Posted by repairguy

Maybe I missed something in an earlier post, but I didn't see any info as to where in the toolchange it fails. Does it do anything or does it stop without starting the toolchange sequence. Lots of things to check, all depending on where it fails in the cycle.

Dan

In my situation the machine comes to the tool change line
T4M6
then just sits there with the previous tool in the spindle. The machine remains in cycle and feed hold will not drop it out of cycle. I must hit reset to stop the machine.

I can then go to edit move back to the T4M6 line and restart and all is fine.

Out of the 80 cycles today it has stopped 3 times.

I'm still open for ideas.

I figure I'll check all my prox switches and make sure everbody is adjusted correctly and none of the wires are ifffy.

[repairguy]

When it fails, does the head go to toolchange height? Does the spindle try to orient?

Dan