Editing generic lathe post

[colton_m]

Hello,

I am wondering if anyone could offer some ideas on where and how to start modifying the generic post MPLFAN.pst?

I have recently started programming an older Hitachi lathe, and I am wasting a lot of time doing manual edits after posting to get this thing running!

First off, the post is inserting a "G18" after every tool change and before EVERY "G02" or "G03" command. They serve no purpose in my application as the lathe is only 2 axis, but instead of just wasting memory it's causing problems. The machine doesn't understand this code and it is actually cancelling my constant surface speed. I would like to know how to edit the post to remove these "G18" codes completely from the program.

Second, this is more of a two part question... At the end of every operation I get code that looks something like this:

M9
G28 U0. V0. W0. M05
T0100
M01

I would like it to post G30 through the program and only use G28 after the LAST operation in the program. The same goes for the M05, that ovbiously only needs to be after the last operation. Also, it would be nice if the "V0." wasn't in the zero return line at all. Again, this lathe doesn't understand it and creates an alarm... There is no Y-axis here.

Finally, one more pet peeve I have about the above snippet of code; On the lathe I am using the first two digits after the "T" command call up both Geometry AND Wear values as well as indexing the turret to the right pocket. Having Txxxx after the zero return lines is redundant and does nothing in my case. I would like to remove them. However, it would be nice to have the turret index back to the first tool used in the program at the end of the program.

Whoever could offer some answers, or other resources to get me started would be greatly appreciated. Up until now my only experience editing posts was to get a random acess tool changer on a mill to pre-stage tools.

Thanks,
- Colton

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[crazythunder]

Well I would suggest your dealer. Most dealers will make these simple modifications for free. I have had whole 5 axis post supplied to me by my dealers, but I was on good standing with them.

Look in the post for this to help you:

pl_retract      #Retract tool based on next tool gcode, lathe (see ptoolend)
      cc_pos$ = zero
      if home_type = one,
        [
        pmap_home   #Get home position, xabs
        ps_inc_calc #Set inc.
        pbld, n$, psccomp, e$
        pcan1, pbld, n$, *sgcode, pfxout, pfyout, pfzout, *toolno, e$
        pbld, n$, pnullstop, strcantext, e$
        ]
      else,
        [
        #Retract to reference return
        pbld, n$, `sgcode, psccomp, e$
        if home_type = m_one, pbld, n$, *toolno, e$
        pcan1, pbld, n$, *sg28ref, "U0.", [if y_axis_mch, "V0."], "W0.",
          pnullstop, strcantext, e$
        if home_type > m_one, pbld, n$, *toolno, e$
        ]

The *sg28ref is the post call for G28. Some people change the define statement in the post where it is G28 to G30. Problem is then they want G28 and lose it. You see you need both. So you can either make a correct change where you make it *sg30 and get the G30 always when you need it and then in the post where the G28 comes out you can then see if you get what you want. I am thinking you may have to add some logic and that is where you really should contact your dealer. Hopefully that is a enough to get you started on the right track if you are so inclined to not contact your dealer.