G72 fix

[papagno-source]

1.start lathe.ini 2.load this file 3.G54 G18 G21 F400 G40 T2M6G43 m3 s100 o100 sub g1 x50 z-40f10000 x100 z-39.999 o100 end sub G72 Q100 X50 Z0 I3 R0.1 g0 x0 z0 m30

This work ok , but if change in

G54 G18 G21 F400 G40 T2M6G43 m3 s100 o100 sub g1 x50 z-40f10000 x100 z-40 o100 end sub G72 Q100 X50 Z0 I3 R0.1 g0 x0 z0 m30

This not is drawed, because ?

It worked properly before this:

Actual Master 2.9.pre0

Information about my hardware and software:

System Debian Wheezy

[andypugh]

I have made some progress with this, but not a great deal.

The "magic" is all in src/emc/rs274ngc/interpg7x.cc

Modifying the area around line 765:

    while(p!=end()) {
    printf("765 x = %f \n", x);
    while(x-tolerance>imag(location))
        x-=delta;
    printf("x = %f\n", x);
    if((*p)->dive(location,x,out,p==begin())) {
            printf("dive dive dive\n");
        if(cycle==1) {
        /* After the initial roughing pass, move along the final
           contour and we're done

I see the "While" execute once for each line in the cycle for the "good" file, then "dive, dive, dive" whereas the bad file runs once and straight to dive.

I haven't figured out yet whether this is due to the p being shorter or the dive() function returning a different result. I really know very little about C++ and this is using a lot of iterators and complex numbers.

Good

Bad

[andypugh]

It seems that imag(back()->ep) gets flipped somewhere before do_g71 the value on entry is +40 and there is no +40 in the G-code.

If the condition below in the "swap" routine is changed to "if (dir_x>=0)" then both test cases pass.

but then the code fails with z = -40.00001

    /* Change the direction of the profile to have Z and X decreasing */
    void swap(void) {
    double dir_x=imag(front()->ep()-back()->ep());
    double dir_z=real(front()->ep()-back()->ep());
    if(dir_x>0) {
        for(auto p=begin(); p!=end(); p++)
        (*p)->flip_imag();
        flip_state^=2;
    }
    if(dir_z<0) {
        for(auto p=begin(); p!=end(); p++)
        (*p)->flip_real();
        flip_state^=1;
    }
    }

[andypugh]

Thanks mark-v-d. Seems to be fixed.