4th Axis rotary indexing:How do 'you' set Z height offset?

[Brendan P]

I was curious to how some of you guys set your Z height offset.

Do you set it from the center of the rotab? (This will result in positive absolute Z numbers in program) Bigger Z number:away from part,Smaller Z number:cutting deeper into part.

 

Or do you set your Z height offset from maybe the top of the part (with result of Minus absolute Z numbers in program.)

 

Or I guess a better way to explain it is: Do you program your part for "Z" from the centerline of the rotab?

[Jayson Kramer]

I alwas program from the center of rotation.

the other way is good if you are using sep offsets for each face.

But I alwas try to follow center of rotation.

[Hardmill]

Center of rotation, Always.

 

 

PEACE

[Greg Williams]

Hi,

 

Centre of rotation for me

[Brendan P]

Thanks,

Before I started programming in my dept. and before we had Mastercam,the other programmer who didn't have rotary capabilities with the limited software they had,used to draw the geo. in the flat and then just manually edit the 'A' (rotary moves)in.

 

So the guys would just set their tools from the top of the part.All absolute Z's would be minus!

This makes for extra work for me.If I continue to program like this,especially if I draw the geo. where it belongs diametrically.

I am trying to get the guys to changebut they are reluctant!God forbid they have to learn something different!

 

PS..I'm starting to believe that it is only my shop that is "F'd" up!!

 

Hopefully enough people will respond to this thread so I can show this to the guys....

[Guest]

Bucket:

I program to the center. I also converted a shop from manual A-axis programming to MC programming. I had good operators that listened and understood what and why I was telling them. I also learned the importance of good setup documentation. Some of the old programs were still floating around the shop. It took several years to reprogram all their parts and get rid of the old hand written programs. In the long run it was worth it because it minimized the confusion in the shop on how 4 axis part are supposed to be set up. Good luck.

[Don S at Barefoot CNC South]

Brendan

Center of rotation here.

[SBA]

center of rotation always

[MetalMarvels]

Always the center of rotation here.

[Jammer™]

Center of rotation here too. I cut different diameter rotary dies so no matter what size I am cutting it is always the same stackup from the table when I touch off my tools.

[McRae]

PS..I'm starting to believe that it is only my shop that is "F'd" up!!

 

Brenden,

 

All shops suffer from some sort of a problem in some areas.

[Guest CNC Apps Guy 1]

Center of rotation ALWAYS, no if's and's or but's! Tell them to pull their heads out and get with THE Program.

[Shady]

Always center of rotation....just makes sense. ~~~~~~~~Shady

[Lathe-Mill]

Brendan

Center of rotation

[chris m]

quote:

---

I'm starting to believe that it is only my shop that is "F'd" up!

---

Nah; just YOU

 

C

[Brendan P]

Thanks for all the reply's,I'm already hearing:

"You're gonna end up with a lot of scrap parts if you go and change now!" from some of the mary's.

I say: "not if you got 1/2 a brain!"

 

Changing will make programming much easier for me.

[Steve Biehl - Cimquest Inc]

Brendan,

we run our MC training classes with Zero on the rotary axis. And I'd guess that close to 90% of our customers do it that way. I worked at a shop where I did a ton of rotary work and it was to the axis.

[Allan Brown]

For simultaneous 4-Axis, the center is the only datum that doesns't budge as the 4-Axis moves, right?

 

That is to say that the datum stays fixed in the control coordinates, but doesn't move with the part. And that will create problems because Mastercam has the datum tied to the part geometry. The tool moves with respect to the part (and datum), meaning that the datum would need to move along with the rotary axis on the machine.

[Tim Johnson]

For fourth axis contouring or for single part indexing I program fron the center. But if I'm running a multi part fixture with no contouring I program from part zero for the simple reason that I only have to program one part and let the macros take over.

[specv]

Maybe im not understanding this, I always program from part zero not the center of the table, or are you guys talking about 4th axis contouring?