4th Axis Z Position

[Tim Simmermon]

I am trying to program my first part using 4th axis positioning. I've got the rotary end of it down, I just have a question about setting my Z Axis zero. The part I am cutting is held in a chuck that is mounted to a tombstone. It ends up that the bottom of the part is about 4" above C/L. Does my Z zero have to be the C/L of the A axis or can I move it? I don't want the bottom of the part to be Z +4.00.

 

Thanks

[Guest]

The "accepted" way of programming 4th axis work that I am familiar with is you always use your centerline as your zero point.

 

Whenever I program on the 4th axis almost everything is a Z+.

 

The guy before me used to program at the top of the part and I can't tell you the confusion that created.

 

Others may do it different but that is how I do it.

 

BTW, what difference does it make if the bottom of the part is Z+4.00 in the control?

 

[ 11-02-2005, 12:47 PM: Message edited by: jmparis ]

[Tim Simmermon]

I also don't see a difference in having everthing be a Z positive. The guys in the shop see it differently though. Every 4th axis progaram we created before we had Mastercam was with z0 being at the top of the part or at the top of the fixture. I am reprogramming a part and just trying to keep everyone happy.

[Guest]

You're a programmer?

 

Forget keeping everyone happy, it'll never happen.

 

[Slepydremr]

If your machine can follow an origin point not on centerline as it rotates..

 

(for example our acramatic could but our okuma is too old and can't)

 

Then you don't have to set z at centerline of rotation

 

But if it can not follow the origin then you will either have to program from centerline or create a different offset at each angle for the operator to pick up

[crazy^millman]

Well been there doen the what the guys in the shop want and what works best in programming and guess what someone has to lose. I always program my 4th axis work for Z0 being center line of rotary vertical or hortzional. I am working on a part right now that goes from about 85lbs to 12lb alot of 4th axis surfacing, 4th axis postioning and standard 3 axis work. I would have to make about 8 models and 10 different CNC programs paste them all together to get something that makes Z0 top of the part. I have one model do all my operations and done. All my indexs all postions and everything is done in one posted program 24 different tools.

 

HTH

 

[ 11-02-2005, 12:53 PM: Message edited by: Crazy^Millman ]

[Tim Simmermon]

You don't even want to know how we used to figure out where our positions were. What a nightmare.

 

We are using Haas Rotary Heads and I believe it can follow the origin, because that is how we used to program.

 

I think I'll stick to the "accepted" way. You're right on trying to keep everyone happy, though!

 

Thanks for your help.