Rigid Tapping G33.1 for Lathe and Milling

[hanifhan]

did G33.1 ( Rigid Tapping ) is supported on Milling and Lathe ? or is there any plan or clue to make it possible because i want to try implement rigid tapping on GRBLHal

[karoria]

I want to also try rigid tapping on mill. If it is experimental, then also I can try out.

[terjeio]

No it is not supported yet - it is on my longer term todo list though. But nice if somebody else will take on the challenge.
I am not sure the current spindle sync code can be used as-is since I do not know how it will behave during deceleration/acceleration of the spindle. Using a stepper as the spindle motor might be easier to get working?

[terjeio]

Pass the original position to the new function in the same way as it is done for mc_thread().
Spindle is reversed by inverting the ccw flag:

pl_data->spindle.state.ccw = !pl_data->spindle.state.ccw;
pl_data->spindle.hal->set_state(pl_data->spindle.hal, pl_data->spindle.state, pl_data->spindle.rpm);

[hanifhan]

hi terje , do u have any clue to make the spindle synchronization always count the encoder and convert it into feedrate , without waiting for the target programmed spindle , im trying to use that kind of thing for rigid tapping

[hanifhan]

or maybe save the previous synchronization feedrate and then send it again with paralel of back to origin Z and CCW spindle , do u think that will be do able for rigid tapping ? here is my code
in gcode.c

    case MotionMode_RigidTapping:
    {
        protocol_buffer_synchronize(); // Wait until any previous moves are finished.

        gc_override_flags_t overrides = sys.override.control; // Save current override disable status.

        status_code_t status = init_sync_motion(&plan_data, gc_block.values.k);
        if (status != Status_OK)
            FAIL(status);

        plan_data.spindle.state.synchronized = On;

        mc_line(gc_block.values.xyz, &plan_data);
        protocol_buffer_synchronize();
        plan_data.spindle.state.synchronized = Off;
        mc_rigid(gc_block.values.xyz,&plan_data,gc_state.position);

        protocol_buffer_synchronize();    // Wait until synchronized move is finished,
        sys.override.control = overrides; // then restore previous override disable status.
       // plan_data.spindle.state.synchronized = Off;
    }
    break;

in motion control.c

void mc_rigid(float *target, plan_line_data_t *pl_data, float *position) {
// Store the original Z position
float original_z = position[Z_AXIS];

// Counter clockwise the spindle 
pl_data->spindle.state.ccw = !pl_data->spindle.state.ccw;
pl_data->spindle.hal->set_state(pl_data->spindle.hal, pl_data->spindle.state, pl_data->spindle.rpm);



//protocol_buffer_synchronize();
// Move the Z-axis back to the original position
float new_target[N_AXIS]; 
memcpy(new_target, target, sizeof(float) * N_AXIS); 
new_target[Z_AXIS] = original_z; 
if (!mc_line(new_target, pl_data)) {
    return;
}



protocol_buffer_synchronize();
pl_data->spindle.state.ccw = !pl_data->spindle.state.ccw;
pl_data->spindle.hal->set_state(pl_data->spindle.hal, pl_data->spindle.state, pl_data->spindle.rpm);

// pl_data->spindle.state.synchronized = Off;

[terjeio]

do u have any clue to make the spindle synchronization always count the encoder and convert it into feedrate , without waiting for the target programmed spindle

I think you should wait for the spindle to reach the target RPM before starting. The tricky part is how to handle the direction change.
Switching spindle direction instantly is a no-no? So you'll have to decelerate/accelerate the spindle in a controlled way?

To get any clues about how to do this I would check out how it is done in LinuxCNC.

[hanifhan]

if wait until the spindle reach target RPM after the direction is change ( assume it is inside the tap ) then the tap is going to break , i think it should have been calculate the speed(feedrate) based on encoder speed and always synchronize it? , gonna find some data on linux CNC first