On Thursday 04 June 2020 19:49:36 Chris Albertson wrote: > That is such a good idea! > > It eliminates all the overhang. I took this idea and combined it with > what I do and made a hybrid. One half of this in made on a lathe out > of steel or aluminum and the other half is printed. The "hybrd" > pulley would last for years. > > This turns an intermediate skill level print job into two > beginner-level jobs one on a lathe and one on the printer. Join the > two with epoxy or CA glue. Some of this group could do this lathe > work before the printer is half done. > > Here is a 3D view of this https://a360.co/3eUpZE6 > <https://a360.co/3eUpZE6> > > Just in case the above link fails here is a render in 2D. I might > actually do this. Of course, this applies to things like helical > gears and so on. > > > [image: HybridPulley.jpeg] > Neat as can be. Lemme see what I can cobble up out of the parametric sprocket kit. I think I've some 1.75" dia alu to make the hubs from.
Looking at this one, 80% done, it looks like the teeth are twisted at a high angle, like 75 or more degrees? Crazy... > > > On Thu, Jun 4, 2020 at 3:48 PM Gregg Eshelman via Emc-users < > > [email protected]> wrote: > > For a toothed pulley with a flange on both sides I'd modify the 3D > > model to make one flange a separate part, with features on it and > > the body of the pulley to align it so that when glued on it will be > > concentric. > > > > To glue PLA, cyanoacrylate (super glue) works well. So does > > tetrahydrofuran, which is in some types of PVC pipe cleaner/primer. > > The PVC cleaners without THF won't bond PLA. > > The ridged surfaces of FDM prints can be used to make parts that fit > > together like they're snap fit. Sizing part fits just right then > > adjusting extrusion can make the same models easily drop together, a > > light press fit that holds but is separable, or a press fit that's > > not tight enough to distort but is never coming apart without > > something breaking. > > > > On Thursday, June 4, 2020, 3:14:31 PM MDT, Chris Albertson < > > [email protected]> wrote: > > If you have not enabled supports and are printing an object like a > > pulley you WILL have a total mess. 3D printer need a surface and > > an part of the part that overhangs with just air onder it will not > > print well as the hot plastic will just fall out the nozzle. > > > > But that cross hatch pattern looks like support base so it must be > > enabled. You can enable support either "from the baseplate up" or > > "everywhere" and you need "everywhere" as at to support the top > > flange. > > > > Yes, removing support is a PIA because on a pulley the teeth will be > > completely 100% inside a ring of support material. > > > > For a beginner you picked a hard project. Most people would start > > by printing a one-inch cube or a 1/2 inch flat washer. Pulleys have > > need of support and have printed threads for the set screw. Both as > > "intermediate level" skills. Horizontal threads always have > > support inside that needs pin punch (hex key) to remove > > > > I had to modify the pulley design so it could print with minimal > > support. Take all the ridges off the outside, make the flange > > thicker and radius the inside of the flange > > > > It is also possible to control the support density and pattern. > > > > Getting all this right nly tak seconds if you know to do it. I > > start in Fusion and vew thepart from al sides to see if it can be > > better designed to reduce the need for support. Then in Cura I try > > a few suport techniques and use preview to see where it is going to > > go. If it looks bad, then back to Fusion to change an angle or > > whatever. This is why engineers like really fast workstatins as > > design is iterative. > > > > I'll look at a file if you can e-mail it. > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > 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) 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
