Out of center axle turning?

[fizzman]

Hi.

In Fanuc, what is a good function to turn an out of center axle. I know it can be done, I just don't know any good functions to do this.

I attached a picture of it. Very nice picture too, 30 sec in Paint.

I would be very grateful if someone has a tip for this. Is it a polygonial turning? e.g G50.2?

Thanks in advance!

[Karl_T]

This why four jaw chucks are made. Mount off center by amount you need.

Karl

[jrrdw]

Originally Posted by Karl_T This why four jaw chucks are made. Mount off center by amount you need. Karl

As long as it's not a self centering chuck, correct???

[fizzman]

Ok, a four chuck solution is ok for the out of center axle itself, but how about the axle in center? By using a non centering chuck I can't turn the big diameter axle...

Thanks for the tip, but I'm looking for a way to do this by help of programming.

[Andre' B]

Unless your lathe has a C and Y axis and live tooling I think you will have to do it in to operations.

If the lengths shown in the drawing are relative you could do it in a mill. And if you do not like the milled finish set up two boring heads for finish turning the two diameters.

[fizzman]

I have both C-and Y-axis and live tooling, but I dont want to mill it, I want to turn it.

But I think it should be no problem without Y-axis as long as the C- and X-axis are synched, right?

[Andre' B]

The problem with just syncing X and C is unless the eccentricity is small relative to the diameter being turned the rake and clearance angles on the cutting tool change a lot when going thru a revolution of the part.

[fizzman]

Yes, I recognize that this could be a problem. But is there a way?

Thanks for all the input.

[Andre' B]

If you are asking if there is a G code that will do it on any lathe with a C axis then no.
If your lathe can do it the info would be in the programming manual.

Here is a specal chuck that can be used for eccentric turning on any lathe with a C axis.
http://www.workholding.com/product2_2_1_1_4.html

[fizzman]

Thank you Andre.

It was a pity that I couldn't do it without an adjustable chuck, but now I know. Thanks!

[M-man]

If you first machine one of the diameters and then use your c-axis to cut the soft jaws to get the "out of center" position for work piece.. You might get a balance problem, but just limit the spindle speed or use counter weights...