On Saturday 18 July 2020 22:18:33 Gregg Eshelman via Emc-users wrote: > PLA should have enough flex for the part of a cycloidal drive that has > to flex. It also is pretty tough so wear would be a minimal issue.
If its tall enough to flex. This PLA seems to be pretty fragile cold. And "cycloidal" hasn't a flex member, its the harmonic's that flex the gear. And there are "harmonic" designs that use a wider belt turned wrong side out. If I could find the files to print one of those, it would already be tried. But I see all these on u-tube but no place to grab the files. I may have to figure out how to reverse openscad to make internal gears. The parametric design tool works well but outputs sprockets too small by a fraction of a percent. I keep expanding the xy scales on the printer by .05% increments looking for the right size but haven't got there yet. Bore sizes are too small too. To get 16.85mm's, I have to ask for 17. And I have come to the conclusion that both cura and merlin that run the enders need to be replaced as neither has a G2 or G3 for circles, so the only belt teeth that reproduce well are the XL sized which can be reproduced as a series of straight lines but actually have a circular gullet when rendered in PLA if inspected with a strong glass. The semi-circular gullet stuffs do not render well at the scales involved. But so far, I have not been made aware of a slicer that uses g2/g3. There are 32 bit retrofit boards for the Enders, but can they do g2/g3? IDK. If they can, I'll get one of them ordered Monday. > Just don't run it fast and/or under a bunch of pressure without some > lube. I suspect a silicone grease made for plastics (like that sticky > white stuff often found in gear drives in cheaper power tools) would > work for PLA. Got a brand name? I've gotten some lubriplate BB grade lookalikes but its not exactly the same stuff. > If the part works well for a while then breaks, print another one. > Print a spare to start with to ensure the one you use lasts a long > time. ;) Murphy's law in reverse, print 3, the first will last forever. But when you do need the spares, they've vanished. :-\ [...] Cheers, Stay safe and well, 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
