On Friday 03 January 2020 12:41:41 andy pugh wrote: > On Thu, 2 Jan 2020 at 21:47, <mark.vandoesb...@hetnet.nl> wrote: > > I've just pushed a new version. This one supports cutter > > compensation for G70 and the use of O words (such as call/repeat) in > > the subroutine used for the path. > > There have been a few attempts made to add these cycles. I did one > myself as a remap as a test of a type-2 algorithm. > https://github.com/LinuxCNC/linuxcnc/tree/andypugh/g71type2remap > > The hope was that someone else who was working on this at the time > would combine the two to give a built-in version. > The reason that I feel it should be built-in is so that cutter > compensation is done in only one place. I am away from home at the > moment so can't easily check if this is the case with your version. > > The main reason, though, that I mention my experimental branch is that > I did document the cycles, with explanatory images. This might be > re-usable, if your version of the G71 cycles behaves the same way. > > https://github.com/LinuxCNC/linuxcnc/blob/andypugh/g71type2remap/docs/ >src/gcode/g-code.txt#g71-lathe-roughing-cycle-turning
Two things about that Andy. 1. All the arrows need a definition of what they represent. 2. And down in the g76 section just below this, there is still no mention of using L and E to cut a long low angle taper for use in a compression locked shaft joint, both for the external thread, and conversely for the nut that fits that thread. I am useing such a connection between the shaft for the motor drive and its being clamped to the ballscrew for X drive on my Sheldon. Define L to put the big end at the left, and E as one "pitch" less than Z. By drilling into the end of that shaft to exactly fit the ball screw, then EDM sawing the walls of this socket into 4 petals, make a custom nut to fit threads at the small end, inserting the ball screw into that socket and tightening the nut 3 or 4 turns, many tons of gripping pressure can very effectively make it one piece. With needle cartridge bearings on that shaft, and roller thrust washers counter sunk so the outside washer exactly fits the countersink in the front of the old hand crank boss so no swarf can get in, my major src of X backlash is the nut, hovers at about 1.3 thou. Part of that is that the nut is mountless, so its mounted in a cage and has felt swarf wipers set into tapered holes in brass plates on each end face, driven by small bolts to squeeze the brass plates, and the nut, in turn squeezing the felt into the threads for wiping a fresh layer of oil on the screw. With the bottom of the cage sealed up with go-2, an annual refill of vactra seems to be sufficient to keep it wet. Its a piece of cake to do, but it does need to be properly explained. But with the current text, you have to think way outside the box to do it. Thanks Andy. 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) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
