Fanuc 0M G84 (tapping) doesn't work anymore..

[Chopit]

***Problem solved, I had the machine turned on all night and the next morning G84 was working again, No changes made to the code or to the machine, It just worked again, The problem is a faulty mainboard***


Hey fellow CNC-folks!

I've got an old Johnford VMC-416 mill (1986?) with Fanuc 0M as controller,

So my big problem is what the title says, G84 has completely stopped working, I get Alarm 014 as soon as the machine is about to start tapping, The code looks exactly the same as it did when G84 worked. When i check the Alarm 014 in the manual supplied by Johnford it says something about the K-value being too high of what's allowed, However, I don't use a K-value and i haven't done it before either (The k-value can be used when you use G91 for repetations or something like that, but i use G90 so i shouldn't have to use the K-value at all, and as i said, It worked just fine before), However i did try using the G91 version with a K-value in the tapping code but with the same result.

I've searched the net for a possible fix but it doesn't help that much, My assumption is that a system parameter has been changed or something is wrong with the board, The later is what i suspect because i haven't touched the system parameters ever and they seem to be intact, But with these older machines you never know


Some misc information:
-M29 does nothing (Seems like some newer controllers need this code to be able to start tapping)

If i check the G-code list in the machine there's a G63 called "Tapping mode"
G63 is used for tapping in Fanuc 21 if im not wrong?

"N...G63...Z...F"
Just for the hell of it i tried using G63 but nothing happens, No alarms, no nothing so i got no clue why it's included in the machines G-code list.

Anyone been through this before and know what i need to do? The tapping is the last operation on my parts and i'd rather not have to tap 250 holes manually, hehe


Oh yeah, I've done the "shut down the machine completely, wait a while, Start and try again-part" a dozen times and it doesn't work either,


I'd be really thankful for some help here

[dcoupar]

Maybe if you posted the section of code where the error occurs...

[jlavery]

Hi Chopit

Make sure you are using G94 feed per minute, and not G94 feed per rev.

[Chopit]

Originally Posted by dcoupar Maybe if you posted the section of code where the error occurs...

As i wrote in the first post there's nothing wrong with the code that's why i didn't include it, This is/was a hardware failure because this morning it was working again without any changes made to the program or to the machine, I even kept the machine turned on all night.

Originally Posted by jlavery Hi Chopit Make sure you are using G94 feed per minute, and not G94 feed per rev.

Yeah, That's the only feed option i can use with this old machine, G95 doesnt even exist


Ah well, Thanks anyways guys

[fanucman]

turn dry run on and see if it works that way..

[gwarble]

couple things to check...

other parameters can affect how your code will be interpreted... so make sure you are using the same as before the problem appeared:

increment system A B C...
g-code system A B C (may change your arguments from decimal/nodecimal values)
decimal point input
macros overriding any g-codes

option parameters for rigid tapping is required as well... if you can check your 900 params...

also, M29 does nothing apparent but it does something in the background (sync's the spindle and axis for rigid tapping) and usually requires an S### argument... and may or may not orient the spindle for you

feed/speed overrides could be pushing the tap speed outside the max rpm for rigid tapping

good luck
- gwarble

[dcoupar]

Is your code a secret? Perhaps if you posted it here someone could help.

[Chopit]

Originally Posted by dcoupar Is your code a secret? Perhaps if you posted it here someone could help.

No, the code is not a secret, But since it's a simple cycle code i don't see any point in posting it. Here you go anyway:

------------
%
:6367
(**** TAPPINGM12 ****)
G00 G17 G21 G40 G49 G80 G90
G91 G28 Z0 X0 Y0
T3 M06
G00 G17 G90 G94 G54 X0 Y0 S300 M03
G43 H3 Z15 M08
G00 X8.0 Y-25.0
G00 Z10.0
G84 G99 Z-21.0 R5.0 F514
G80
G00 Z20
G00 G17 G90 G94 G55 X0 Y0 S300 M03
G43 H3 Z15 M08
G00 X8.0 Y-25.0
G00 Z10.0
G84 G99 Z-21.0 R5.0 F514
G80
G00 Z15
M09
M05
G00 G91 G28 Z0.
G28 X0. Y0.
G90 G80 G40 H0
M30
%
------------

And for a third time, It's working again, read the first post for more information.

[dcoupar]

Never thought to look at your original post to see that it was solved. Sorry to have bothered you.

[stevo1]

Originally Posted by dcoupar Is your code a secret? Perhaps if you posted it here someone could help.

LMAO. Dave you crack me up.

Stevo