Grettings all; Using one of these 6 wire, 12 volt elderly floppy stepper driver motors, as 4 wire on a to6600 driver I have a choice of fitting a sleeve over the driver hub on the motor shaft, which when cleaned off is 16.8mm in diameter, meaning the minimum tooth count for a GT2_3mm belt will be about 24. Or I could fab a miniature gear puller and get down to the motors 5mm shaft by pulling the existing hub, meaning I'll need to find metal pulleys, but fleabay has only GT2_2mm for sale.
With a single reduction stage consisting of a 24 tooth pulley on the motor, driving a 180 tooth, the resulting pointing accuracy would be 0.06 degrees. But for astrophotography, they are mentioning .01 arc-seconds or better, which seems a lot finer than a single reduction stage will get me to from a 1.8 degree motor whose best accuracy will be .45 degrees. So how much more geardown do I need? And whats the best way to do it? I am thinking of trying to print a harmonic drive that's not any bigger than these motors, which are 40mm square. But I can't imagine one being under 75mm around. Maybe even ditch this idea and make a 2 stage harmonic drive. Or cycloidal, anything these teeny motors can drive as I can bang them pretty hard with a 24 volt supply and a tb6600 driver set at its lowest current. The cycloidal seems like it would be more compact axially. Thanks. 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-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
