Fanuc 6T skipping over program code

[mzk_t32b]

I have a older Wasino Lenuc-J with a fanuc 6T control series 992 version 7.

It seems to occasionally skip over code in the program.

ie a few times it has not indexed to the correct tool called out in the program,but continues to run as though it has.
( Can be a big problem when this occurs )

The spindle may fails to turn on after reading M03..

It usually occurs after the machine has been running most of the day ( 7-8 hours ). It is a intermittent problem, but causing great concern

Any ideas or suggestions

[sinha_nsit]

Difficult to believe, but I would like to know the answer to this problem.
Is it happening on the same program?
Or, possibly a typing mistake in the other program, which the control is ignoring???

[mzk_t32b]

This happens using the same program that has been running parts all day....the machine misses a command to index the turret, and continues with the wrong tool

[sinha_nsit]

Are you using #1000 series variables in your program?

[mzk_t32b]

no variables are being used..

below is a sample of the beginning and
ending of the programmed tool being used. ( typical )

G96
G50 X12. Z6. S2000 M8
G0 S1200 T0101 M3
X10. Z.1
G1 Z-2. F.012
~
~
G0X12.Z6.T0100
M1

I have different tools used , it may miss
indexing on any one of them. ( ie it stays on the previous used tool )

Do you know which diagnostic numbers show the
turret position ?, could it possibly be the encoder/resolver
on the turret causing this problem ?

As i mentioned before, at times the spindle will not start.
The tool moves up to the part, and sets, ( because the feed
is per revolution. )
It seem to be hung up ( must power down and power up
to get the spindle to start up again )

[sinha_nsit]

It is not a programming-related problem. Possibly, some hardware problem including as simple as bad contacts. Let some hardware expert comment on this.

[mzk_t32b]

Thanks for taking the time to read and reply sinha_nsit your help is appreciated

[DouglasR]

On some fanuc cnc's there's a fiber optic connection that bridges the gap between the cnc and the machine. if there's a problem there, it may cause ugly things.

[mzk_t32b]

Referring to my first post where I am having
problems with a FANUC 6T-A skipping over program
code , tool and spindle commands.

Anyone familiar with the input AFL ( aux function lock )?

Seems to be a Input FANUC has provided to allow the operator
to skip all programmed M, S and T codes in the program.
( if I do not understand this function please tell me )

On the 6T-A control Diagnostic #36 bit 0, and #100 bit 0
is where the state of this input is read.

When this bit is a 1, the machine will skip or ignore any M,S or T
code in the program and not send the command to the machine side.

While observing this Diagnostic value it will flicker between 1 and 0

It will also settle in and stay either value at different times.
There is not a switch on the operator panel to control it.

The manual for 6M model B shows C01 (15) cable #1 wire 15
as the input path
this is a model 6T model A.. would this connector and wire
be the same as a Model B ?

I ask because there is no cable connected to this terminal
on the I/O board.

I see no foreign material on the board such as metal chips etc.

Do i have a bad board, can i jumper around somewhere to
hold the input.


Any ideas or comments or corrections would be valued

Thanks, Floyd

[tc429]

good job- you've went thru all the right steps to finding your problem, wish more of our maintenance guys could do that too

from there, I would verify if that control has the big gold colored box above the i/o card (dont think it does- we had some Lenuc-J's years ago) pull the lid and look in there among all the wire wrap pins for chips too, its a common issue. Sounds like maybe one of the input channels is failing on your i/o card- if you can squeeze a wire in there safely, try pulling it to ground thru a 2k resistor and see if anything changes. if it quits flickering, look thru your connection manual again at that input- should show some internal resistors on the board side that go to another pin- if using +24 inputs (99.9% of the time) that common needs connected to 0V to keep the input terminals pulled low (think those cards have 3.3k onboard pulldown arrays).

I dont recall if those had internal PC-Model A or B option turned on- if they have internal PMC, the pinout in the manual wont necessarily be correct...you may need to look thru your ladder for the 36 or 100 bit coil, make sure the same address writes to it. Ive got a little cheat sheet I'll look up and attach later on address/pinouts, not quite all of them are in the manual. I'm not 100% sure the A/B controls had the same addressing- know the B had a lot more bits available, but unsure if the basic stuff was moved around or not...

a couple notes on that machine- pretty sure our wasino had the little red 'encoder' on the turret- actually just a rotary hall effect switch, with a magnetic rotor...if the gearset gets rusty, the shaft can snap off- I recall it was 6mm drillrod, ours broke on a sunday, I ran home and pulled a clutch shaft out of my r/c helicopter, as it was the only place I knew to find a piece...its cheep if you can find it, might want to keep a piece onhand- and better yet, keep the turret lubed

I recall the front spindle bearing went out of one of the wasinos, the bearing was unavailable- special order, like 20 grand and 2 months to have made... the guy working on it noticed the races were in fair condition, cleaned/polished, got a bunch of plain ground balls from the local bearing house, and son of a gun if it didnt hold a finish still 2 years later...think it cost 40 bucks for the balls.

Good luck on that old beast...its a heavy machine, think its kinda cool its still running after all these years. its got 6045 servo amps too dont it? the amps and the big relay board were the biggest issues we had with ours, they were pretty beat when we got rid of them...I remember the 'fuji' spindle amps eventually got trashed/updated to something else...this was like 20 years ago. cool machine as they got like a friggin 10" thru spindle hole IIRC, biggest ive ever seen

[tc429]

dont have my updated i/o sheet here...but did look up the 6T i/o list and it shows G8.0 as the actual AFL signal.

[fordav11]

it could be as simple as a dirty connector on the I/O board. with the machine OFF, you could try pulling each cable connector out separately, spray with special electronic contact cleaner then push back in and out a few times to clear any minor oxidization. Otherwise it looks like you might have a heat-related bad connection or dry solder joint on your I/O board. Possibly directly where the connector plugs are soldered into the board. You might try inspecting the connections with a high powered magnifier (8X or similar) while gently flexing the joints then re-flow the solder on the connectors if you find any that look suspect.

Also inspect the entire I/O board thoroughly for any bad solder joints. Heat-related dry joints are pretty common faults in older electronics, especially in dusty/dirty environments and/or when exposed to vibration.