Inch/Rev for tapping

[Hertz]

Hey guys, I am having issues with Mastercam changing my feedrates and rpm in the parameters. I have a 3/8-16 tap that I want to use. My post outputs G95 everytime (which is what I want) but if I put say 1000 RPM, it changes my feed from .0625 to 62.5. Then it outputs 62.5 inch/rev.If I change the feedrate in the parameters to .0625, it changes my rpm to 1. I can't change both as it keeps overriding my selection. Is there somewhere to tell it to leave it to what I set?

[Guest]

You should never set your .0625 in the feedrate, that if calculated properly will be 62.5 IPM, this way if you change speeds the feedrate updates but will still output the IPR value

 

The post shold have switches to calculate the IPR output and output it

 

Not know what post you are using and what's been done to it....it's not easy to say what needs changing or needs to be switched

 

A lot of posts will have something similar to thsi

 

 

tap_feedtype       : 1     #0 = Units Per Minute (G94)

                           #1 = Units Per Revolution (G95)

ptap$            #Canned Tap Cycle
      pdrlcommonb
      result = newfs(17, feed)  # Set for tapping Feedrate format
      if met_tool$,
        [
        if toolismetric, pitch = n_tap_thds$  #Metric NC Code - Metric Tap
        else, pitch = (1/n_tap_thds$) * 25.4  #Metric NC Code - English Tap
        ]
      else,
        [
        if toolismetric, pitch = n_tap_thds$ * (1/25.4)  #English NC Code - Metric Tap
        else, pitch = 1/n_tap_thds$           #English NC Code - English Tap
        ]
      pitch = pitch * speed #Force Units Per Minute for regular Tap cycle
      pbld, n$, sg94, e$
      pcan1, pbld, n$, *sgdrlref, *sgdrill, pxout, pyout, pfzout,
        prdrlout, *pitch, !feed, strcantext, e$
      pcom_movea

You "may" only need to change the output

 

*pitch, !feed

 

make sure you don't have

 

!pitch, *feed

[Hertz]

You should never set your .0625 in the feedrate, that if calculated properly will be 62.5 IPM, this way if you change speeds the feedrate updates but will still output the IPR value

 

I don't understand. I want the feedrate to be .0625. I don't want it to ever change since the feed for a tap does not change. Not sure why you say not to set that. What would I put in the feed box? I understand why it posted 62.5. Its cause I set my spindle speed to 1000. If I change the spindle speed to say 500, it will change my feedrate to 31.25. The problem is the post outputs G95 for tapping cycles regardless. Sorry if I sound dumb, but I'm not getting what you mean.

[Guest]

I know you don't understand

 

Set your feedrate for IPM in the feedrate and let the post do it's work

 

I can't say it any more plainly.

 

I do not have a single tap setup across many libraries and customers with an IPR setting, but I can output either by only using the correct post for the proper machine/customer

 

Set your library up right, set your post up right you will never have to fiddle with it again

[crazy^millman]

You should never set your .0625 in the feedrate, that if calculated properly will be 62.5 IPM, this way if you change speeds the feedrate updates but will still output the IPR value

 

The post shold have switches to calculate the IPR output and output it

 

Not know what post you are using and what's been done to it....it's not easy to say what needs changing or needs to be switched

 

A lot of posts will have something similar to thsi

ptap$            #Canned Tap Cycle
      pdrlcommonb
      result = newfs(17, feed)  # Set for tapping Feedrate format
      if met_tool$,
        [
        if toolismetric, pitch = n_tap_thds$  #Metric NC Code - Metric Tap
        else, pitch = (1/n_tap_thds$) * 25.4  #Metric NC Code - English Tap
        ]
      else,
        [
        if toolismetric, pitch = n_tap_thds$ * (1/25.4)  #English NC Code - Metric Tap
        else, pitch = 1/n_tap_thds$           #English NC Code - English Tap
        ]
      pitch = pitch * speed #Force Units Per Minute for regular Tap cycle
      pbld, n$, sg94, e$
      pcan1, pbld, n$, *sgdrlref, *sgdrill, pxout, pyout, pfzout,
        prdrlout, *pitch, !feed, strcantext, e$
      pcom_movea

You "may" only need to change the output

 

*pitch, !feed

 

make sure you don't have

 

!pitch, *feed

 

 

This is the correct way to approach this. I agree with John here and I never have to fight with Mastercam when it comes to tap. I set my speed and done.

 

HTH

[Hertz]

OK thanks guys. I'll call my re seller on Monday to have them fix it the way you showed.

[Hertz]

.............. 

[CJep]

Hertz back to your OP, the feed rate and rpm should update when changing one of the fields. They are directly proportionate to one another when using the G84/74 tapping cycle. What JP & Ron are saying is set your desired RPM and let the post convert that to IPR.

 

There are switches in some of the posts to set IPR for tapping or if you're using the MpMaster post go to the misc values and activate integer #6.