Jump to content

Welcome to eMastercam

Register now to participate in the forums, access the download area, buy Mastercam training materials, post processors and more. This message will be removed once you have signed in.

Use your display name or email address to sign in:

Converting Post VF-TR to UMC 750

Recommended Posts

Hey yall,

I am attempting to update a generic Haas VF- TR post to accommodate my UMC 750. I have all the rotary axis and directions set, but I am getting this weird rapid motion between operations when the rotary repositions, instead of retracting and doing one single rotation, it seems to be attempting to track the x,y,z moves with the rotation. See the attached NC code, I've deleted a lot of the fluff to make it easier to read. 

I am fairly green at post editing, where do I need to be looking in the post to fix this?

Thank you!



haas post test vftr.NC

Generic Haas VF-TR_Series 5X Mill.pst

Link to comment
Share on other sites

With the "Null Toolchange" Post Block in the Generic Fanuc 5X Mill Post, there is a logic condition at the very top, which checks for several conditions.

(I'm talking about 'p_goto_strt_ntl', not the 'ptlchg0$' block.)

Those conditions are as follows:

  • if the Work Offset Value does not equal the Previous Work Offset [workofs$ <> prv_workofs$]
  • if Top Map is enabled, and the current value of 'n_tpln_mch' does not equal the previous value of 'n_tpln_mch'. [top_map & (prv_n_tpln_mch <> n_tpln_mch)]
  • if Primary Rotary Axis has moved [prv_p_abs <> fmtrnd(p_abs) OR if Secondary Rotary Axis has moved [prv_s_abs <> fmtrnd(s_abs)]

So, 'Null Tool Change' should already "detect" if there is a B or C motion. It uses the last "OR" condition in that complex "if" statement, to detect the change in Rotary Position.

In this Null Tool Change Block, you'll see two comments:

      ##### Custom changes allowed below #####
      ##### Stop custom changes #####

Make the changes you need in-between these comment lines, and you won't "break" anything.


Try adding just a "String Literal Comment" to identify 'where in the post' your output is coming from. I find this much easier to do, than run a 5-Axis Post through the Post Debugger.


      ##### Custom changes allowed below #####

        if n_tpln_mch > m_one, #Toolplane mapping mode
          #Enter your mapping scheme here...
          pbld, n$, pwcs, sgabsinc, *xabs_s, *yabs_s, *zabs_s, *p_out, *s_out, e$
          pbld, n$, *xout, *yout, *zout, e$
          pbld, n$, pwcs, sgabsinc, *xout, *yout, *zout, *p_out, *s_out, e$

      ##### Stop custom changes #####

Notice that I broke the "Else" result into a "User Defined Post Block". ( [  ] ) 

That allows "multiple lines of output", from a single "True" condition. That is the reason you see the Square Brackets on the lines that follow the "If" condition.

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

×   Your link has been automatically embedded.   Display as a link instead


  • Recently Browsing   0 members

    • No registered users viewing this page.

Join us!

eMastercam - your online source for all things Mastercam.

Together, we are the strongest Mastercam community on the web with over 56,000 members, and our online store offers a wide selection of training materials for all applications and skill levels.

Follow us