Picking off on a square

[danrudolph]

Maybe this is a newb question? What is the best approach to picking on a square?

The part is essentially 3/16" stock squared up with a bit of OD turning at the corners, the diameter of which is .170+/-.0002" so I am trying to avoid using a round collet and potentially damaging the part/diameter tolerance.

Based on what I've seen online, the move would be to turn to a small dia, move onto the part while both spindles are at C0.0 and spin off the part using the back spindle.

How do I get the C0.0 on both spindles to be aligned on the flats using a square collet? If you can align them, like for hex stock, could you do that here and cut off like normal?

Machine: A20 VII, Material: 316L

[g-code_junkie]

If you are using round stock then machine the part and complete the milling of the square then stop machine(do not open main collet).then you can perform the phasing prodcedure to store the orientation between sub and main spindle.In your program you will have to use the "R" on the g814 or g114.1 line and also use m77.If your sub spindle collet is not keyed you will have to phase the spindles every time you remove the collet.

[danrudolph]

Thanks, that makes sense. I wasn't sure if it worked that simply or not.

[cogsman1]

IT IS THAT SIMPLE.
Mill the part

PRESS Reset
Move the sub spindle onto the part by handwheel
Close the collet.
Go to MDI
Key in "G899 R1"
end of block, insert
Cycle Start
DONE

Just be sure when you are in MDI and execute the "G899R1" that you are in "All Block" NOT "One Block" or you may not complete the proceedure. Very common mistake.