This has already been done on Merlin. Merlin is the software that interpret g-code for most 3D printers.
The way it works is there is a distance sensor on the print head and it probes the entire bed in a grid pattern. It ALWAYS finds that the bed is not level and not flat. There are several kinds of probes sorted. One is a simple microswitch. Then after probing the bed and seeing that it is not flat or square it computers a transformation matrix and then later all X,Y,Z values in the g-code are transformed. In the end you have a part that is perpendicular to the bed but maybe not vertical. Depending on where on the bed your part is it might be leaning in a different direction. It works well within reason. Actual errors need to be only a few thousands. In my case the bad is slightly bowel shape with the =center being about 0.2mm deeper than the corners. This level of error is easily corrected. On Sat, Sep 8, 2018 at 12:23 PM Gene Heskett <[email protected]> wrote: > Greetings all; > > I am about to give up on this bedwear comp project. > > How I determine the amount of correction needed has been tried by > watching the dial as Z is moved, taking notes as to which way the center > of the wobble (the spindle is running about 15 rpms) moves, and putting > that DRO's RAD in the hal files lincurve "setp" list. Makes it worse, > change sign of lincurve y-val, still worse. Seems like the correction > is being multiplied by 3 or more. > > I have run it to a lincurve X-val-nn point, and using the jog dial, > centered the dials wobble on zero, then put the obtained rad into a > y-val-nn, again making it worse with either sign. > > So how do you folks derive the correction needed? > > I'm assuming the offset itself is in radius, not diameter. In which case > the needed radius correction max's at about 2.5 thou. And that the sign > is the "tricky" part. > > Thanks everybody. > > -- > Cheers, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
