Hi Hood, thanks.
  Watching a thread on encoders running now at the W9 forum. Looks like it may get worked on, will be interesting to see how it transpires.

Thanks again for sharing your research,
Russ

Be sure to update please Russ, will be very interested specially if it can be proven to work correctly.
I was in hopes that the claims that the DSPMC/Hicon could be proved as it would have provided me with a large boot to kick some arses

Hood

Well - it isn't really that it does it wrong as it doesn't do it like any other control and no one has made a canned cycle to fix it yet..  (that I know of anyway)

G33 spindle synchronized motion in linuxcnc was made to be very flexible..  You are not limited to z axis moves.  ie - you could cut a scroll if you wanted to.  or a fusee.  That though required that the pitch be calculated along the move.  So if you move x and y the same amount (45deg angle) the pitch is along the hypotenuse.  If you are cutting a taper - you have to specify the pitch along the xz move - not the z move.  (clear as mud?)  People have made some gcode subroutines to do the calculations..  Here is a good thread (no pun intended).

http://www.linuxcnc.org/index.php/english/forum/40-subroutines-and-ngcgui/13006-ntp?limitstart=0

Here is G33 from the manual
http://www.linuxcnc.org/docs/devel/html/gcode/gcode.html#sec:G33-Spindle-Sync

sam

Ha ha Sam, yes I cut fusee and scrolls every day of my life, really handy, who the hell needs pipe threads anyway

Better not ask you about all the other issues Steve Blackmore has mentioned that really pi$$ him off about LinuxCNC as you will have to get your spin doctoring skills turbocharged.

Just having a bit of fun Sam

Hood

Oh that is ok .. - steve has been more than vocal about problems he has with linuxcnc.  the ones I know about are..

1. tapered threads (you have to calculate the pitch along the hypotenuse) -  Not a show stopper as you can cut tapered threads either with a little right angle trig or gcode subroutine.  

2. Jog while paused - work has been done on this maybe in the next release (not been keeping up on it)

3. 1 segment look ahead limitation in the trajectory planner - This is what I have been helping test and am really excited about.  A developer had taken up the challenge and has made a N lookahead trajectory planner that is in the testing stages right now.  we have used steves gcode to test that the new tp.  

It is what it is.  

sam

Quote from: skunkworks on March 15, 2014, 10:21:31 PM

Well - it isn't really that it does it wrong as it doesn't do it like any other control and no one has made a canned cycle to fix it yet..  (that I know of anyway)

G33 spindle synchronized motion in linuxcnc was made to be very flexible..  You are not limited to z axis moves.  ie - you could cut a scroll if you wanted to.  or a fusee.  That though required that the pitch be calculated along the move.  So if you move x and y the same amount (45deg angle) the pitch is along the hypotenuse.  If you are cutting a taper - you have to specify the pitch along the xz move - not the z move.  (clear as mud?)  People have made some gcode subroutines to do the calculations..  Here is a good thread (no pun intended).

http://www.linuxcnc.org/index.php/english/forum/40-subroutines-and-ngcgui/13006-ntp?limitstart=0

Here is G33 from the manual
http://www.linuxcnc.org/docs/devel/html/gcode/gcode.html#sec:G33-Spindle-Sync

sam

Ha ha Sam, yes I cut fusee and scrolls every day of my life, really handy, who the hell needs pipe threads anyway

Better not ask you about all the other issues Steve Blackmore has mentioned that really pi$$ him off about LinuxCNC as you will have to get your spin doctoring skills turbocharged.

Just having a bit of fun Sam

Hood

It is what it is. 

Sure is Sam and it is the reason I have the utmost respect for you, yes you tout LinuxCNC as being the dogs danglers but unlike all the others you are willing to admit that its not perfect, the rest dont like to admit that and I think that is why it takes many years for even fundamental things to change.
Mach3 is not perfect either, far from it in some areas, and some things just cant be done with it hence the fabled Mach4, lets just hope we both live long enough to see things improve in both camps 

Hood

Russ, got a mail from Wotjek today saying they will at some point be doing a M76 for Mach3, so suppose now its just a wait to see which comes first, SS managing to use encoders without the delay, M76 macro from CS-Lab, Mach4 Turn or proof the DSPMC/Hicon can. I know which one I would bet on being last

Hood

 

Thanks Hood,


Russ