Makino FNC-106A - Fanuc 6M 4th axis problems

[nlh]

Hello,

I was wondering if anyone could give me a few pointers or things to check in regards to the following problem.

Machine is a Makino FNC-106A. It's a big 50 taper machine with a Fanuc 6M control, aprox. 1983 model year. It has a Tsudokama(sp?) 4th axis rotary table. It appears to have been installed from the factory. It has a fanuc servo drive in the cabinet and "4th axis module" add-in card on the mainboard. When the machine is powered up, there are no alarms. XYZ can be homed and manually jogged with no issues. 4th can also be homed and jogged with the handwheel with no issues. The problem comes when trying to move the 4th through programmed commands, either in MDI or in a program. It simply won't move. The machine will stop and wait for it to move, but the 4th just sits there. Strangely enough, there are no alarms.

I know next to nothing about Fanuc 6 series controls. I have run a 6T powered lathe but only for part of a day. My experience is with older Yasnac and Mitsubishi (Mazak M2) controllers.
This is not my machine, it belongs to a friend. I'm just trying to help him get it going. If need be I can get a copy of his program. According to him his format is as follows, "G1 A220 F20.". The program uses the 4th as an indexer rather than cutting in 3 or 4 axis at a time. He has also tried using a G0 and pretty much anything else he can think of, all with the same result.

Any input on this would be appreciated.

Thanks,
Nate

[dcoupar]

Have you tried M-codes to unclamp the B-axis prior to move? Possibly M10 to unclamp, M11 to clamp?

[nlh]

dcoupar,

Thanks for the response. I know I haven't tried any M codes. I will give it a shot soon. Although you mentioned the B axis. The machine calls the rotary table A axis. Also because this is a full 4th, shouldn't it move as any other axis moves without the need to unclamp it? What if I wanted to pull a move with XYZ4 at the same time, will it still need to be unclamped? Just wanted to clarify.

Sorry, these questions probably sound stupid but I have no prior experience with anything except indexer's which were actived by M code.

Thanks again

[dcoupar]

Sorry, I meant "A". Most of the 4th axis rotary tables I've seen have had a clamp of some sort (pneumatic or hydraulic). When you jog or zero return the clamp releases automatically, but you need to program them to unclamp and clamp while in MDI or Automatic operation.

[Dan Fritz]

There is a little-known input signal called "4NG" (or something like that). It causes the control to "Neglect" the 4th axis. This signal is normally used when you disconnect the 4th axis and use the machine as a 3-axis machine. Look for a switch labeled 4NG and see if the 4th axis is just turned off.

[nlh]

Great info guys!

Gives me a few things to check this week. I'll post back when I know more.

[nlh]

Ok, I was able to get back to the machine yesterday.

We attempted to clamp or unclamp with M10, M11 but nothing happened. I'm guessing those weren't the correct M codes for this particular machine but I have no machine specific programming manual (and even a generic Fanuc 6M progamming manual) to go by. It has a pnuematic clamping system that can be clearly seen to work when the table is moved manually.

Concerning the "4NG" signal. Would this still allow the table to be jogged manually even though it would not operate in MDI or AUTO mode? I came across a portion in the maint. manual that mentions this signal and how it can be checkd in DGN. Unfortunately I forgot to check this when I was at the machine so I will have to check it again next week.

Another question, usually what is the cause of a 401 alarm? This is intermittent and doesn't seem to be related to the 4th. One day the machine powers up fine, the next it has alarm 401 and the X servo amp has a red LED.

Thanks,
Nate

[cnc-it]

Hi Nate I also have a Fanuc 6M with 4th axis. I use M10 and M11 to clamp unclamp...if i'm using full 4th for wrapping I use a different post which unclamps at the start of the prog and clamps at the end to finish.

If I use MDI I have to manually unclamp (push button or MDI) the 4th before keying in my move in degrees ie G0 B360. (mine needs the decimal point at the end or it just sits there with no alarms or anything!)

Hope this helps!

John

[nlh]

Thanks John!

I'll give it another go as soon as I can.