90 degree shift in axis of post

[m_morgan]

Hey guys,

 

I'm modifying the mpmaster post to suit a loan machine which we have been supplied with, and as part of the test program I'm using, I want to tilt over on the B axis by 5 degrees and machine a pocket at an angle.

 

However, when I output the code, I get a C90. for free like this:

 

...

G0 Z10.

C90. B5.

X-157.507 Y34. Z-31.47

X-157.071 Z-36.451

...

 

It also strikes me as strange that the B and C axes outputs are reversed.

 

When I change the 'secondary shift', parameter from:

 

shift_90_s : 1

to

shift_90_s : 0

 

I get the following instead:

 

...

G0 Z10.

C90. B5.

X34. Y157.507 Z-31.47

Y157.071 Z-36.451

...

 

and all my Xs are now -Ys, and vice versa!

 

Help!

[m_morgan]

Anyone have any idea how to change the C90. to a C0.?

[Mike S @ S4A]

....is this a mill/turn machine or 5 axis mill?

[m_morgan]

It's a 5 axis mill, with a tilting head (C is attached to Z, with B attached to C)

[john316]

.

 

The MpMaster Post isn't made for 5-axis machines. You should be using the Gen5X post.

 

.

[m_morgan]

Son of a Diddly!!!

 

OK, thanks for the heads up John316!

 

Back to the drawing board!

[m_morgan]

I've rechecked the post I'm using, and I was just mistaken before. I am using the MPGEN5X post.

 

I'm still getting the same 90 degree move on the C axis.

 

The layout of the spindle/rotary axes is the same as this picture:

 

http://www.nmine.com/5axis/spindle.jpg

 

Imagining that the spindle angle can also rotate in C, and you are standing looking in the Y+ direction, that picture to me is:

 

B-20. (or thereabouts) C0.

 

But my machine wants to rotate the C axis by 90 degrees, so that the tool is tilted away from you.

 

How can I correct the 90 degree movement using the GEN5X post?

 

Sorry if my explanation is a little odd, but I've been working straight for 18 hours. :cuckoo:

[Mike S @ S4A]

check in the machine def (.mmd) file as to where the "home position/orientation" is set...

my intital question (mill turn vs. 5x mill) was along that tangent; home position for the millturn has the B axis pointing at the back of the part (y- direction from your analogy)

so to get pointed downward "from the top" would mean an initial 90 move....

Has your local reseller been any help?

what your sim# ?

[m_morgan]

I'll have a go at altering the machine def., but it seems that anything I do in there has no effect on the posted code. It's as though the post itself is making all the decisions.

 

As for the local reseller, my boss contacted them, and they are arranging to make us a post for the ACTUAL machine, which works differently to the LOAN machine we have at the minute. There's a lot of politics going on, and I'm not about to lift the phone and ring them to get an earful!

 

The reason we got a loan machine was that the machine tool reseller made a mistake about the configuration of the machine, so we're stuck with a loan machine that can only do 3 axis work, and I'm getting hassle for not being able to get the 5 axis working properly.

 

My current position is between Rock and Hard Place.

 

Thanks for all the help so far guys.

[Guest]

I am wondering if you would not be better off using the Generic Fanuc 5 axis post that come with Mastercam instead of that old MPGEN5X post

[Mike S @ S4A]

I second that...