Yes I already turned them down. Currently running max velocity at 8m/min and 750mm/sec2 I think.
Which is way slower than it used to run. On Wed, Sep 23, 2020, 5:50 AM N <nicklas.karlsso...@gmail.com> wrote: > There are limits in trajectory planner adjustable in .ini file > DEFAULT_ACCELERATION= and MAX_ACCELERATION= you tried them? > > > Hi again, > > Indeed it is pretty hard to use spindle load if is doesn't change thru > > the corner. I suspect it does on smaller machines but that is not a > > generalized solution. > > Just for experimental purposes it might be interesting to decrease the > > velocity thru a corner see if it helps. Lacking the adding another row > > to the matrix should control jerk but the may not be the whole solution > > when dealing with a change in direction. So much to learn so little time > > (and energy). > > I suspect the 'big boys' do some pretty fancy adaptation to get good > > smoothing thru the corners. Of course it is all propitiatory and those > > patents take a long time to run out. Silvia McFarland (sp?) in her > > masters thesis (Uni BC) used sin accel rather than trapezoidal. Might > > help. I think traj control get much more critical as velocities get > > really radical. Some of the new Brothers with 30 tapers absolutely > > scream. When the machinist describes stepping back from the machine when > > the tool moves toward him then is must be really impressive. > > > > Dave > > > > On 9/21/20 4:55 PM, andrew beck wrote: > > > hey dave > > > > > > I hear you. I might get good at coding myself soon.. but would love > to > > > solve the problem. > > > > > > I don't think the spindle load could really help much though. > > > > > > I am machining plastic and aluminium and the spindle load doesn't > > > noticeably change in corners. I more need a limit on the initial > > > acceleration for a split second I suppose > > > > > > or go the full way and have something that analyzes the G code path and > > > calculates the best speed and path for the machine > > > > > > regards > > > > > > Andrew > > > > > > regards > > > > > > > > > > > > On Tue, Sep 22, 2020 at 11:35 AM dave engvall <dengv...@charter.net> > wrote: > > > > > >> HI Andrew, > > >> Just because I have ideas does not imply I can implement them. ;-) > > >> However, I believe there is a velocity pin that might be used to slow > > >> down in corners. Since the spindle loads up going thru corners it may > be > > >> possible to monitor spindle load and back off velocity thru the corner > > >> which should make milling a bit smoother. Adding jerk control > involves , > > >> as you know, adding another order to motion. (see first sentence). ;-) > > >> A lot of bright people are involved in linuxcnc but they all have > their > > >> own pet projects. Just the way it goes. > > >> Hang in there, your heart is in the right place. > > >> > > >> Dave > > >> > > >> On 9/20/20 8:19 PM, andrew beck wrote: > > >>> Hey guys > > >>> > > >>> just a few thoughts here. > > >>> > > >>> I have a high speed cnc machining center (cnc mill) > > >>> > > >>> it has 16mm pitch ballscrews and weighs 6ton > > >>> > > >>> linuxcnc is awesome and does a great job controlling it. I make > plastic > > >>> injection molds and lots of 3d machining all the time. plus all the > > >> little > > >>> jobs that a cnc is great for. > > >>> > > >>> I think the only thing lacking from linuxcnc for my use is some sort > of > > >>> jerk control for corners. there may already be something around that > > >>> solves the issue though without jerk control. so what happens is > when > > >> the > > >>> machine changes direction the whole machine vibrates and jumps > around. > > >> its > > >>> quite bad. enough that I may rubber mount the electrical box lol. > > >>> > > >>> I have accelerations of 750 (i think it is mm/sec2) > > >>> > > >>> and max rapids of 8m/min > > >>> > > >>> I would love to turn those up to like 25m/min rapid and 2000mm/sec2 > > >>> accelerations > > >>> > > >>> has any one tried any form of jerk control yet on linuxcnc? or > wants to > > >>> have a play and code it. I have 3 6 ton cnc machines that will all > use > > >>> linuxcnc so very keen to solve this jerk control issue. > > >>> > > >>> regards > > >>> > > >>> Andrew > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
