Post problem 4th axis winding up

[Ronald Glatts]

Machine Mori Horizontal with 4th (B axis)
Control Fanuc 18i
Software Mastercam V9.1

I am programing swarf 5 axis tool paths only using the B axis.
The post keeps winding the B axis.
I have three operations programed.
If I select all three operations for posting, the B axis winds up.
Each consecutive operation will start at a larger B value than where the last B left off from the prevous operation.

If I post each operation seperatly then the B moves are not wound up.

Let's say the first operation moves from B-45. to B45. (rough cut)
The second operation does the same thing. (finish cut)
The third operation does the same thing again. (2nd finish cut)

What the post puts out is .....
First operation will position at B-45. then feeds to B45. then retract.
Second operation will position at B315. then feed to B405. then retract.
Third operation will position at B675. then feed to B765. then retract.

How do I get the post to reset the B axis at each contiguous operation?

Ideally the code would go ....
B-45. to B45.
then B-45. to B45.
then B-45. to B45.
for each operation.

[inkydo69]

So the code comes out with messed up numbers?

[HuFlungDung]

I don't know Mastercam, but I can imagine the scenario.

I would guesstimate that the rapid positioning move to the same start position between operations is inferred (in your mind) but is not actually present in any of the operations. Can you devise a way to insert a repositioning move at the end of each operation to put the tool back at the start point?

Or, can you limit the useful range of the indexing head in your post setup, say +/-180°?

[tobyaxis]

This is most likely a post processor problem. Did you change your post or edit any part of it?

[Superman]

More than likely, a post problem ( pa, pr, prot, or protary call-up in the post )

Possible work-around, try force a toolchange to try and set axes internally back to zero

[Ronald Glatts]

Originally Posted by Superman More than likely, a post problem ( pa, pr, prot, or protary call-up in the post ) Possible work-around, try force a toolchange to try and set axes internally back to zero

Tried the forced tool change. Did not work.

[Ronald Glatts]

Originally Posted by tobyaxis This is most likely a post processor problem. Did you change your post or edit any part of it?

Tried a post that has not been modified and got the same results.

[tobyaxis]

Originally Posted by Ronald Glatts Tried a post that has not been modified and got the same results.

Have you tried your Dealer to see if they have a working post for you. I imagine you can get help with editing your post here. I don't edit posts but there are a few others here that can help.

[Superman]

Originally Posted by Ronald Glatts What the post puts out is ..... First operation will position at B-45. then feeds to B45. then retract. Second operation will position at B315. then feed to B405. then retract. Third operation will position at B675. then feed to B765. then retract. How do I get the post to reset the B axis at each contiguous operation? Ideally the code would go .... B-45. to B45. then B-45. to B45. then B-45. to B45. for each operation.

Just a wild question..
The angles you state that are bigger than B45, are these the values in the NC program or are they what the machine screen displays while running the program ?

1 more
What post are you using ?
paste in the first 12 lines of the .PST file
( this may allow us to have some idea of where to direct you to the problem area needing fixing )

[Ronald Glatts]

Originally Posted by Superman Just a wild question.. The angles you state that are bigger than B45, are these the values in the NC program or are they what the machine screen displays while running the program ? 1 more What post are you using ? paste in the first 12 lines of the .PST file ( this may allow us to have some idea of where to direct you to the problem area needing fixing )

I have attached a ZIP file that includes a MasterCam file and a post. Post the program and see what code you get. You will see that the B axis winds up if you post all operations at once. If you post the 2nd or 3rd one alone you will will not see the B axis wound up.

[Ronald Glatts]

I found a 5 axis post in X3 that does not wind up the 4th axis. Hurray! So I guess I just need to find out how I can fix my V9 post to prevent the wind up. Have tried some of the posts of the MC V9 CD but have not found positive results.

Sorry, but I'm still resisting using X3 even though I have paid for it. Still waiting for MC to make it a little more intuitive. I find X3 awkward and unstable.

[inkydo69]

Originally Posted by Ronald Glatts Sorry, but I'm still resisting using X3 even though I have paid for it. Still waiting for MC to make it a little more intuitive. I find X3 awkward and unstable.

I would say your missing out then! Yes at first it is different but I use to think the same way. I can tell you this now that I use x3 I couldn't tell you even how to use V9 anymore lol

Just go to a refresher coarse on it through your dealer. Its worth it!