On Tuesday 11 August 2015 04:41:16 Dave Caroline wrote: > There is no such thing as "instantly" there is a delay until an edge > is detected, a delay before the software has looked at the current > position and direction and a delay before Z starts to follow the > reversal, the sum of delays is a strain on the tap, making all numbers > less will reduce the strain. > > I have made a 50 slot wheel for my 5 axis in readiness to try rigid > tapping. > > 200 counts per rev, Z screw is 1mm per rev, that is about .2 thou from > the encoding and more for any software delay to Z command. > A ball Z screw of 1mm/rev? Even my toy lathes 16mm PD z screw is 5mm/rev. Its also geared down from a 425 motor, 2/1.
> Someone with a .2" pitch screw and 8 slots has a possible error of > 6.25 thou before seeing the encoder edge. not something I would try. 8 slots=32 edges for an ABX encoder. So it outputs an update every 11.25 degrees A 1/2"-13 USS tap, and an 8 slot encoders best would be a 0.00240384615385" error. Worst case maybe 2x that at the inner turnaround. With the reative lack of rigidity in my carraige, I would try it on scrap the first time. I suspect it would be 100% usable & way better than I could do by hand. Thats _If_ I had the drive parts laying there, installed. I have a kit that puts all metal sprockets and backgears in it, but haven't found the round tuit yet. Because my jackshaft, which is a 3/1 reduction from a 1 HP motor already, has a 9mm output shaft, and the new kit is 8mm, I think I will order a lower sprocket with 2x the teeth and a suitably longer XL belt. IMO there's not enough sprocket hub to bore it to 9mm and have it survive, and from the papers, my max revs will be under 1000 in high gear due to the pre-existing 3/1. But that bridge is not yet in sight. I may use the last plastic sprocket to make a jackshaft wih an 8mm output & change that out just so I can use this sprocket & see if its really too slow. But that will be after I have the GO704 fully calibrated. > Dave Caroline > > ---------------------------------------------------------------------- >-------- _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
