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Fanuc 3T Parameter Spindle Indexing 900?

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Plastic
Joined
Feb 27, 2019
OK - wrapping up the work on the Citizen Cincom F12 swiss lathe (Fanuc 3T control).
That last thing I'm trying to get going on this machine is getting the C-Axis to index.

I can run an M18 and the live tool spindles will turn on along with the main spindle indexing to "zero" and locking up.

Then I try to command a C180. or C90. and it skips right past that line of code until it reads an M20.
The stepper drive unit must be working.

I almost think having the ability to index the spindle was a 900 parameter option - can anybody confirm?
 
Is your machine a full C axis or an indexer?

I have some Citizen notes about this. Not specifically for the 3T but may still be applicable to you. I think the machine I got this from had a Mits control, but it's been so long ago I don't remember.

My notes say that for a full C axis you call M18 and C on the same line to index. So to do 180 degrees you would have M18 C180.

It also mentions at 5 degree increments a lock pin can be engaged on that line by adding K1.

M18 internally sets the G0 mode so be sure to restate G1 if cutting in the next block.



If your machine is not a full C axis then M28 S in 15 degree increments will index the spindle.
 
Vancbiker,

Thanks for the response.

No it is NOT a full C-Axis, but it is supposed to index in 1 Deg increments.

Tried all of the above to no avail.

M18 indexes the spindle to zero per a hall effect sensor.
M28 just engages the indexing mechanism without "zeroing".

I followed the manual's example program and it seems to just skip over any "C" commands.
 
Sorry to give you bad news

I did yes,

Entered as C90,

MDI takes it in as C0.0090,

I recently had to try this on my 3T control. problem is it's from 1983 so not too smart this control. I have been using this machine for years just having to drill a cross hole 90 degrees, until i went through the manual and found it is only capable of 90 degree indexing on the "c" axis. had to move the milling to a Mill, not happy with second op's.
 
I recently had to try this on my 3T control. problem is it's from 1983 so not too smart this control. I have been using this machine for years just having to drill a cross hole 90 degrees, until i went through the manual and found it is only capable of 90 degree indexing on the "c" axis. had to move the milling to a Mill, not happy with second op's.

So you were in fact able to drill a hole say at 0 deg AND @ 90 deg?

What does your code look like to index the C?
 
Does your 3T have a couple of dials like this on the front? Our 3T uses M28 and M29 to index (once you call M18) to index the spindle the desired number of degrees - i.e. if the first dial is set for 50 then when you call M28 it will index the spindle 50 degrees. If you call a M29 it will index whatever the second dial is set for, in my case it's set for 1 degree. If you call M28 again, it will index 50 degrees again, for a total of 100 degrees.

Screenshot from 2020-06-01 16-09-31.jpg
 
I've used a swiss machine with a 2T or 3T that had dial wheels like that for the spindle and you called S1, S2, S3 for your spindle speeds. Maybe old but still makes good parts fast.

I run a part on our 3T that runs for weeks at a time (10,000+ parts). The machine ain't fancy, it ain't fast, but it just sits there and makes good parts day after day, week after week.
 








 
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