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Fanuc "Not 0" Control on VMC's?

  • Thread starter Ox
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You're missing the boat here:

0T / 0M are both "0" controls.

"Zero Turning"
"Zero Milling"

Any of the models will be configured for one or the other.

The A900 control on my 1983 Cinci mill was better as far as the opperator is concerned than an early "0" control.


Think Snow Eh!


Think Snow Eh!
The 21T and 21i controls on my multiple Cobras are good controls. The 21i has the memory card reader. But it's old 1999/2000 tech. 512MB compact flash card. Correct me if I am wrong on this feature, but it's not a modern memory card or USB. I never used em! Also have a 21i on my Mori MV40E. Mori brands that control as MSC500. Kinda silly. "Mori Seiki Control 500"
It's all Fanuc. Pay no attention to the man behind the curtain I guess!
(Insert comment about Mori not wanting Fanuc to appear on the outside surface of their machines of this era HERE)

The 21 series control are basic controls. The insert chamfer, radius are there like on 18's but you can't use a comma to insert. You must sign the move with -/+. Omitting + with nothing. Hardinge provided a nice page in the Cobra books showing all the situations where the correct sign would be used based on tool movement. Oh, the good ole days!
On the mill, the 21i has some tool path logic. When programming a 180 degree arc, you do not have to hold the control's hand by using quadrants. It gets what you want with less commands. All in all, the 18 controls are better but the 21 series works fine once you know what it wants.
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OK, maybe y'all can help me with this riddle?

Maybe this is common? It seems absolutely asinine to me, but hey....

My machine defaults to G54. Says so right in the manual.
This makes set-up a PITA!
So what I have done now is that I leave G54 set to zero's, and I use the remaining offsets.
G53 only works on the line used.

But what is even more concerning is:
For whatever reason, I have to double the tool offset when setting up.
The CRT - while maintaining G54 as a default, does NOT include the length of the tool that is loaded in the spindle at all times.

So I come down to touch off, take the Z (negative - I hate that too, but seems all too common?) value, and then looking up the tool length for that tool, and then doubling it and adding to the Z value. Then I enter that number into my program.

What in the world?
Why would I need to double it?

Are these Fanuc defaults?
Or maybe just "0" defaults?
Or just really bad implementations?

If I git a mill with an 18 on it, should I expect this same BS?

Is there some params that I can edit that would help to make this a somewhat useable machine?


Think Snow Eh!
What is the length of your tool coming from? Are you measuring it in a presetter offline, or what?

On the position page, you would ALWAYS want to use the machine coordinates, not the absolute coordinates, when setting Z (or xy for that matter). Simply add the length of your tool to the machine coordinate value.

So if you measure your tool to be 5.123" long, and you traveled to machine Z-15.456" down from home, you would add (or technically subtract) those 2 numbers (-15.456 + (-)5.123) = Z-20.579

Although I don't understand. What are you doing when you say "enter that number into my program" ? I thought you were just trying to set a work coordinate. Are you just programming actual coordinates from home? I hope you're not using G92!!! (yes, g92 on a mill is a valid way to program but dangerous and I suggest avoiding it)

There is a parameter that makes it so the last offset you used is default when you hit reset. Usually it defaults to G54 but if you used G59 and hit reset, you could still be in G59 if you change to parameter.

There is a parameter that shows absolute coordinates either including or excluding your tool length offset, as well as cutter comp offsets. However, afaik you can't get the machine to automatically apply the tool length of the tool in the spindle to the absolute coordinate display while the machine isn't in the middle of a program.
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Offline tool length.

Your answers are per - what?

Fanuc in general?


Think Snow Eh!
I would say fanuc in general. I do the same on 16i, 21, 0, 15.

Some machines behave a little differently but there's not much different on any of them. Newer controls just have a few more parameters that control how positions are displayed. But I would always use machine coordinates for setting. And we also use a presetter offline.
So you don't have any response pertaining to the need of doubling the tool length - right?


Think Snow Eh!
No, but it sounds like you're doing something wrong? Do you have to do the same thing when looking at machine coordinate values instead of a zeroed G54/absolute value?

Did you activate the tool length before you moved the tool down? My method does not require activating G43Hxxx or anything.

I guess pictures might help.
Running G57

Doo the math between those two.

Also added a copy of the code, in case somehow I have it added 2wice.
G20 and G43 being bashfull up there in the header.
Spacer line before N1.

As I said, I have a half dozen or more Fanuc lathes, but this is my first [Fanuc] mill.

IDK what the deal is with pic 59?
I took it with a real camera, not a phone.
When I open it on the card - it is right.
Why is it turned sideways here?
I've never had that happen before! ??? :eek: :o


Think Snow Eh!


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Here's a cpl more pics showing where I took H24 out of the code.
The tool is prox in position while showing 7-8" to go yet, with a TL of 3.7 or whatnot...

Weird to me!

Now, with that said, the jobs run fine with multiple tools.
It's not like some are not reaching and others are crashing.


Think Snow Eh!


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What happens if you move g43 to the line with h24?

I would always call up a new H with G43 on the same line.

In your example without H, you can see H0 is active (shows up near the "dist to go" readout)
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Same difference.

I don't think it has anything to doo with the code tho, as I can start fresh, and doo an M6 in MDI, and when I touch off in Z, I will need to double my TL and add - to enter into my Fix Offset page.

As much as I dislike the Siemens, they sure seemed to work as I "the opperator" would expect it to.
If I had that setting there, the CRT would display to the tool tip. (on either the REL or ABS screen I guess...)
I have 2 mills just like this one (well, 3, but 2 inline) with Siemens controls on them.


Think Snow Eh!
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Are you sure you don't have any value in G53?

Any chance you have a g47 or g48 in your code somewhere? they are listed as "Axis offset double increase" and "Axis offset double decrease". I have never used them and no idea what they do. it's the only thing that makes sense to me unless we are missing something simple, like a value in g53 z.
What doo you show canceling those G codes?
Just G49?


Think Snow Eh!
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I cycled G49 in MDI ... no change.

The Z-24" is a bogus value.
Running the Z up to O/T - it is just north of Z0, so that seems OK.
Then a tape measure, and my working plane would be in the ballpark of Z-21.5 or so.

So, again =


Think Snow Eh!
Let's take another stab at this.

Your screenshot shows a "wear" page, are there any values for 24 in there? Should be 0

If you have 3.71 in geometry and 3.71 in wear, they will add together.

(none of my 0 controls have a wear page for offsets, only length; we use offsets 61+ for cutter comp offsets)
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So what I have done now is that I leave G54 set to zero's, and I use the remaining offsets.
G53 only works on the line used.
What heathen uses G53 instead of G54? :D

We have one of those newer Fanuc Smart Plus controls on our Hyundai. It's much much better than the old 0 days.....but it's still a Fanuc.
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