Harmonic Drive (Nema 23) 3D-printable by Trollox

Last crawled date: 3 years, 1 month ago

Intro:
For my final exams i am constructing, printing and building a 6-axis robotic arm in style of the UR robot arms ("universal robots").
Since original harmonic drive gearings are too expensive for me (one costs about 600€) im trying to build my own version.
Im using 6mm steel softair BBs for the flexible bearing inside of the gearing.
I already printed an approx. model of the gearing, which even works (handdriven).
However this project is still work in progress and i will add everything in the next few days.
UPDATE: i have built a first prototype (check the photo), but i didnt like the way the bearings work, they were not precise enough to fulfill my quality standards. I therefore redesigned the mounting cylinder, enclosure and bearings. first i tried to fix the inner rings of the bearings with a thread on the mounting cylinder which didnt work either, at least not if im printing with a 0,8mm nozzle. In order to press the inner rings of the bearings on the mounting cylinder im now using the same holes im using to transfer the radial forces from the mounting cylinder to the flexspline. Also i updated all other files here on thingi.
OLD UPDATE: I updated the following Files: "Lagerkäfig Flexkugellager", "Lagerkäfig Schrägkugellager", "Gehäuse", "Motorhalterung".
OLD UPDATE: I now created a more detailed version of the gearing which is compatible with Nema 23 motors. I will now check if everything works out but it takes some time to print...
OLD UPDATE: My Nema 17 Motor isnt powerful enough to drive the gearing yet. I will check if a nema 23 Motor which is compatible with the ustepper motor driver or radds motor driver, delivers enough power. Otherwise i will add a planetary gearing ontop of the nema 23 or go with another motor driver.