Need insight from C-axis programmers.

[g-codeguy]

I posted this elsewhere, but I know there are some REALLY capable guys on this forum, so...

 

I've done some C-axis programming, but nothing fancy. I have a job that I programmed from the center of a 7/32 inch ball mill. No tool comp. Set-up person has to subtract .109 for Z-axis and .218 for X-axis after touch off.

 

He didn't even tho it says to in 3 separate places in the header. Okay then, I'll just subtract these values from the program. Easy enough, right? Wrong!

 

Z-axis works, of course, but the X-axis is close only on the C0 slot. It cuts too much off both sides, tho not equally. The other 3 slots are way off, and, in fact, the 180 slot doesn't cut any chips.

 

Why??? Obviously I am not understanding something that is basic to those familiar with C-axis programming. As I'm thinking about it, the thought occured to me that maybe I should have added .218 instead of subtracting on the 180 degree slot. Problem is the zero degree slot didn't come out right either.

 

I modified program back to the original figures, and job is now running. I'd like to understand how to program it from the sides of the tool so the set-up person doesn't have to remember to move the offsets. (I realized too late that I should have left the Zs alone so only X-axis would need an offset. Easy to change, tho.)

 

Since this is the Mastercam forum I should add that this isn't laid out in lathe. We didn't have any live tooling posts at that time, and in fact don't have a working one yet.

[crazy^millman]

quote:

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We didn't have any live tooling posts at that time, and in fact don't have a working one yet.

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Well look to Mplmaster and try that and see what the code looks like, The generic Lathe post should give you code pretty close. All of these post are free and can be modified to run on just about any machine with C axis.

 

I would look in the post and see where you are starting and ending your geometry. View 3 is important and not going through center line is important as well.

 

HTH

[Murray Mold]

I'm not too sure what you're trying to describe, but we have a Mori and when I do c axis, the operator has to put a radius value in the offset register and also tell it that it is an X or Z milling head

 

HTH

[Bryan Johnson]

changing offsets with c-axis cuts can give unexpected results.

In the example where you cut a square on the face of a part. If you try and fudge the X offset, the result will be that the sides are no longer flat.

[g-codeguy]

Murray, machine has no option for telling it X or Z milling head. Ball mill is programmed from the center of the radius, but is touched off on a probe.

 

Ron, what is View 3? Are you referring to Right Gview? Part is not layed out in Lathe. Until this year most all my programming has been manual. If I needed to mill a hex, I layed it out in Mill, scaled X to double it, changed Y to C, and cut-and-pasted cutting moves to my program.

 

For this job I layed out the profile when looking at it from the right, offset, drew .218 diameter arc, analized it, typed values in program.

[crazy^millman]

Do you have a Mastercam Lathe Seat to use ???

[g-codeguy]

Bryan, part looks kind of like a cage. 4 openings. Finished with a .750 dia. keycutter that has the shank turned down to .200 max dia. for about 3/4 inch to clear front lip. I added the ball mill to rough these openings out to try and keep from twisting the .200 dia. section off the rest of the shank.

 

I know I'm not explaining it well, but have no way to post the drawing.

[g-codeguy]

Ron, we have 3 lathe seats.

[crazy^millman]

Can you send me the file??

[g-codeguy]

Ron, I will be on vacation until Friday in case you try to reach me and wonder why I won't respond. Won't be near a computer.

[crazy^millman]

Ok I got hit hard today so may be a couple days before I can get back to you anyway.