On Wednesday, December 22, 2021 12:45:11 PM EST John Dammeyer wrote: > > From: gene heskett [mailto:ghesk...@shentel.net] > > > > On Wednesday, December 22, 2021 4:24:30 AM EST John Dammeyer wrote: > > > Here's the 140 Tooth cup and 147 Spline for a 20:1 ratio with 0.5 module > > > > That's a rule violation for a two point drive, the count diff must be a > > power of 2. > > What rule? Where's it written? Why?
I've seen it someplace quite a while back. Basically you need the same count of teeth on both halves of a loop such as we are poking at. That part does change when you switch from an eccentric armature like I'm useing, of a 2 legged ball bearing such as you are poking at. My eccentric is less of a stress concentrator than your dual bearing, so theoretically the loose belt lasts longer. I'm making some mods to mine, as I just built a 60 tooth pulley that is driven onto the chuck axle, fitting so tight I had to drive it on with a deadblow hammer. So that totally does away with at least a degree of backlash the OEM had because their machined in key was quite sloppy in the key slot. This allows me to make my drive thicker with much stronger gears. And while I was stretching the armature, I saw some empty space that could hold a $1.70/copy bearing, bracing up the end of the armature that isn't supported by the motor bearings. I had pretty good luck printing the 60 tooth stuff, so this newer version will have 100/102, running from a 100 spline loose belt, giving my a 50/1 ratio. With the smaller pulley on the chuck axle I'll have room to build a belt tensioner, something I had no room to do before. But I can get a better finish out of the Prusa, but when the parts to fix it arrived, I found the square nuts I had were about .2mm thicker than the pocket it is supposed to fit into. So I next need to make a nut pocket in some alu so I can grind the surplus .25mm off the nuts I have with a CBN disk.. That will fix the prusa. Probably tomorrow as it's forecast for rain meaning I'm not working at unpacking and assembling a new bike still sitting in the shipping crate in my driveway. So the quest for perfection continues. Take care and stay well 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, 1940) 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
