tapping problem

[Anonymous]

I use selca 3035 and when I have to tap I create the tool and set the pitch and to get the right feed rate I am obliged to set the spindle speed 1000 at this point I have to go to the gcode to manually change the spindle speed and set it lower ... ... is it possible to modify the selca file to solve this problem?

[Marco.Takx]

Hi @Anonymous,

I’ve read your question twice but I don’t know what you exactly want. 

Post Processor editing you can modify it yourself.

You need some JavaScript knowledge.

You also can contact your Local Reseller in the link below how can help you.

HSM post adjustments needed? Find your right contact here.

If my post answers your question Please use  .Accept as Solution & Kudos This helps everyone find answers more quickly!

[Anonymous]

Hi, I try to explain myself better ... so if I have to do a M8 tapping step 1.25 I create the tool and if I want to put the spindle speed 300 I can't put it in the tool creation because when I use the milling I tear the male because the tool advancement is wrong the F value .......in practice if and step 1.25 I must have F1250 if and step 0.8 I must have F800 so when I create the tool I am obliged to set spindle speed 1000 but as a value it is high then every time after creating the gcode I have to open it and change the spindle speed from M3 S1000 to for example M3 S300

[johnswetz1982]

Is your code changing to Feed per Rev for that operation?

[Anonymous]

Selca is an odd controller.

g84 requires a thread lead in thousands of a mm for the "F" value.

http://www.helmancnc.com/selca-g84-tapping-fixed-cycle/

This is noted in the Selca post itself, but for some reason doesn't work. I have the same issue and usually get by using a floating holder and only tap to get a thread started, and finish on the bench. 

https://forums.autodesk.com/t5/fusion-360-manufacture/tapping-with-selca-post-processor/td-p/7806253 makes note of a likely fix, but I've not tried it. 

[Anonymous]

Thank you I tried but it doesn't work

[Anonymous]

Is there a difference if you select a different tapping cycle? just normal tapping vs. right hand tapping?

[Anonymous]

nothing changes because it basically multiplies the spindle speed by the step so there's always a wrong F value

[Anonymous]

I need to figure this out, as I'd like to run taps as normal in this machine now. I'm no Java programmer, but the HSM post book is a decent reference.

It looks as if the stock post isn't setup at all for FPR in um, as it certainly doesn't do the proper math, despite it being noted in the post as such:

case "tapping":
    case "left-tapping":
    case "right-tapping":
      if (!F) {
        F = tool.getTappingFeedrate();
      }
      // F is in um per rev
      writeBlock(
        gCycleModal.format((tool.type == TOOL_TAP_LEFT_HAND) ? 74 : 84),
        getCommonCycle(x, y, z, cycle.retract),
        conditional(K > 0, "K" + kFormat.format(K)), // optional
        feedOutput.format(F)
      );
      break;

Page 4-126 of the post manual gives a great example of a FPR calculated cycle:

case "tapping":
 var F = cycle.feedrate / spindleSpeed;
 writeBlock(
 gRetractModal.format(98), gFeedModeModal.format(95), gCycleModal.format((84),
 getCommonCycle(x, y, z, cycle.retract),
 (conditional(P > 0, "P" + milliFormat.format(P)),
 pitchOutput.format(F)
 );
 forceFeed(); // force the feedrate to be output after a tapping cycle with pitch output
 break;

I'm going to play around for a bit to figure this out. If anyone's decent in Javascript (I'm certainly not) any help would be much appreciated!

[Anonymous]

I've still yet to figure out what this machine requires for tapping to work. I have a production job where machine tapping would be rather nice to get working, If someone could take a quick look at the math, the feedrate is never proper.

http://www.helmancnc.com/selca-g84-tapping-fixed-cycle/
"thread lead in thousands of a mm."

Code, as written in the post I'm currently using. I'll attach the full post here also, but do note I've edited it to work on my specific machine and it outputs O-offsets and not tool offsets

case "tapping":
    case "left-tapping":
    case "right-tapping":
      if (!F) {
        F = tool.getTappingFeedrate();
      }
      // F is in um per rev
      writeBlock(
        gCycleModal.format((tool.type == TOOL_TAP_LEFT_HAND) ? 74 : 84),
        getCommonCycle(x, y, z, cycle.retract),
        conditional(K > 0, "K" + kFormat.format(K)), // optional
        feedOutput.format(F)
      );
      break;