I would suggest that you calibrate the xy shrinkage, and z shrinkage in your printer slicer, instead of compensating for it in your design.
> On Mar 25, 2022, at 3:29 PM, gene heskett <[email protected]> wrote: > > Greetings all; > > It has come to my attention that one of the potential failures in my > harmonic drive with a loose belt experimentation, which seems to be > caused by the unequal shrinkage in the xy direction as opposed to the z > direction is at least partially caused by the nozzle diameter. If I > attempt to achieve a zero clearance bearing simply by shrinking the dummy > ball from about .5mm bigger than the bearing, as it shrinks, the wider > edges of the bearing groove come into zero or a slight preload condition, > leading eventually to a race fatigue split at the center of the races > width. Working in openscad, a scale command would fix this by shrinking > the bb shape used for clearing that groove, only in the x direction. > > Th question is how much would it take to transfer the majority of the > stresses on the race from being on the outer edges of the race, to be > more concentrated on the center of the race, with an eye toward reducing > the splitting force on the bearing race. > > 1% x shrink, 2%, 3%, what would be the ideal amount of shrink to > compensate for the printers .4mm nozzle, being used to only lay .12mm per > layer? > > Seems to me there ought to be a way to mathematically predict how much > that shrinkage diff there is. Attached, an extra 2 lines to draw that > away from the bearing itself, showing how little the difference is for a > .97 x shrink. > > Comments plz? > > 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, 1940) > If we desire respect for the law, we must first make the law respectable. > - Louis D. Brandeis
> _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users
_______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
