G84 without spindle feedback

Hi,
Is it possible to use G84 without spindle feedback ? Floating holder is used. Now when
"M03 S100
G84 X100. Y100. F300 R3 Z-40
"

is issued machine moves to R3 but that is it Z-40 is not done.


Tero

I will try it. Is it possible to add this feature to Master?

Tero

I did try releasing G84 of comments but I got this:

It seems thread pitch is not brought into funtion convert_cycle_g84 at all. It is defined with F300 in G84 function. And it should produce 3mm/rev for START_FEED_SPEED_SYNCH. Or should I comment that line out? We have 100 Rpm and feed of 300mm/min that should be enough for floating tapping.

Tero

I tried:

START_FEED_SPEED_SYNCH(3, 0);

And now machine moves to position and remains at R-level no alarm but no Z-40 movement either. How to go forward?


Tero

This should be in form:
CHKS((direction != CANON_CLOCKWISE),
NCE_SPINDLE_NOT_TURNING_CLOCKWISE_IN_G84);

cycle_feed(block, plane, x, y, bottom_z);
STOP_SPINDLE_TURNING();
START_SPINDLE_COUNTERCLOCKWISE();
cycle_feed(block, plane, x, y, clear_z);
STOP_SPINDLE_TURNING();
START_SPINDLE_CLOCKWISE();

I will try to get it working tomorrow. It seems someone has worked on this years ago but it is not yet merged in master:

git.mah.priv.at/gitweb?p=emc2-dev.git;a=...826d8ff000ff37a03fb3

Tero

It is working. But I noticed that using Feed Speed and Max Velocity overrides affects feed while in G84 threading cycle. This should NOT be. There is a big risk of damaging something if feed is for some reason set to 50% or 200% percent before or while tap is in hole. Is it possible to go around this? Here is my quick hack:

CHKS((direction != CANON_CLOCKWISE),
NCE_SPINDLE_NOT_TURNING_CLOCKWISE_IN_G84);

cycle_feed(block, plane, x, y, bottom_z);
STOP_SPINDLE_TURNING();
START_SPINDLE_COUNTERCLOCKWISE();
DWELL(2);
cycle_feed(block, plane, x, y, clear_z);
STOP_SPINDLE_TURNING();
START_SPINDLE_CLOCKWISE();

#if 0
START_SPEED_FEED_SYNCH();
cycle_feed(block, plane, x, y, bottom_z);
STOP_SPINDLE_TURNING();
START_SPINDLE_COUNTERCLOCKWISE();
cycle_feed(block, plane, x, y, clear_z);
if (mode != CANON_SYNCHED)
STOP_SPEED_FEED_SYNCH();
STOP_SPINDLE_TURNING();
START_SPINDLE_CLOCKWISE();
#endif

It would be best to integrate Michaels work from git.mah.priv.at/gitweb?p=emc2-dev.git;a=...826d8ff000ff37a03fb3 but I still need to confirm it still works with current master since it was written 4 yrs ago.



Tero

I will try to add that piece of code to current master within next few days. That would add both G74 & G84 threading cycles with optional P word for Dwell at bottom of thread. But I still would like to know how to make feeds during this cycle to ignore feed override switches?


Tero

Hi,

I was able to get his code to build(after manual insertion of mods to few files). I have few questions:

Patch has a/src/emc/rs274ngc/interp_array.cc:

-/* 740 */ -1,1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+/* 740 */ 1,1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,

But currently this line has:

/* 740 */ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,

So it does not match original line above and I do not have a clue how to get this correct?

Also feature needs to be added so that when changing direction at bottom of thread motion wont wait for spindle_at_speed. Due to mods to taskintf.cc also this wont work:

int emcSpindleSpeed(double speed, double css_factor, double offset)
{

if (emcmotStatus.spindle.speed == 0)
return 0; //spindle stopped, not updating speed

return emcSpindleOn(speed, css_factor, offset, 1); <==
}

int emcSpindleOn(double speed, double css_factor, double offset, int wait_for_at_speed)
{

emcmotCommand.command = EMCMOT_SPINDLE_ON;
emcmotCommand.vel = speed;
emcmotCommand.ini_maxvel = css_factor;
emcmotCommand.acc = offset;
emcmotCommand.wait_for_spindle_at_speed = wait_for_at_speed;
return usrmotWriteEmcmotCommand(&emcmotCommand);
}

I got an error that emcSpindleSpeed passes too few arguments to function emcSpindleOn. I solved this by adding 1 to function call(so wait for at speed is on). But I do not believe it is correct way....

Below is same code from 2014:

int emcSpindleSpeed(double speed, double css_factor, double offset)
1373 {
1374
1375 if (emcmotStatus.spindle.speed == 0)
1376 return 0; //spindle stopped, not updating speed
1377
1378 emcmotCommand.command = EMCMOT_SPINDLE_ON;
1379
1380 if ((emcmotStatus.spindle.speed < 0) && (speed > 0)) {
1381 emcmotCommand.vel = speed * -1;
1382 emcmotCommand.ini_maxvel = css_factor * -1;
1383 emcmotCommand.acc = offset;
1384 return usrmotWriteEmcmotCommand(&emcmotCommand);
1385 } else if ((emcmotStatus.spindle.speed > 0) && (speed > 0)) {
1386 emcmotCommand.vel = speed;
1387 emcmotCommand.ini_maxvel = css_factor;
1388 emcmotCommand.acc = offset;
1389 return usrmotWriteEmcmotCommand(&emcmotCommand);
1390 }
1391
1392 return -1; //can't have negative speeds
1393 }

Also how can I get diff of modified files?



Tero

I believe I was able to solve array correct for enabling G74 would be: /*740*/ 1,-1,-1,-1,-1,-1,-1,-1,-1,-1, 1,-1,-1,-1,-1,-1,-1,-1,-1,-1, right? Now I still have to solve emcSpindleSpeed function call and how to get diff against current master so I can easily install this patch again. Also would be nice to know how to make these cycles to ignore feed override.

Tero