Mulit-geneva

thingiverse

Not recommended for beginners. This is an overly complex Geneva wheel model, inspired by a demonstration example provided in SimLab Composer Mechanical V6.1. Designed in Moment of Inspiration (MOI), simulated in SimLab Composer Mechanical, and printed primarily in PLA on an Ultimaker Original. Some smaller components were printed in ABS on a Robox. This is not an easy print. The largest part, the Frame, is difficult to keep flat even with PLA, making the use of a brim highly recommended. With a brim, the Frame barely fits on the Ultimaker after some fiddling to find the right angle. Print Settings Printer Brand: Ultimaker Printer: UltimateMakerOriginal Supports: No Resolution:0.2mm Infill: Various Notes: Difficulty was experienced in making larger pieces, which I believe resulted mostly from a worn-out extruder drive wheel. It has also made printing recommendations difficult to give. Nevertheless, using 1.2mm wall sections and 60% fill on the Frame is suggested for sufficient strength in the connection of the taller posts to the base of the frame. Otherwise, suggest 1.2mm walls and 30-40% infill. A temperature increase from 210C to 220C was done because of extrusion problems encountered. Only Keeper Old and KeeperTops were printed on the Robox in ABS with default fine settings. The design evolved over time, and the assembly made is not the latest. To create the same as I did use Frame Old and Keeper Old and make two Keeper Tops (which are not needed in the newer version). A new Hagen Extruder Drive Wheel for the Ultimaker has been ordered because it's out of commission. In the Old design, the Keeper that carries the drive parts is attached to the frame through press fit Keeper Tops. However, this is difficult to disassemble. On the other hand, the later design uses screws to connect those components. Three-millimeter-by-ten-millimeter-long stainless steel button head cap screws were used for all screws. To see the 'Thing' in action, check out this video: https://youtu.be/xYAFBgePTWM. However, it's worth noting that my hand blocks a lot of what's going on in the video. The mechanism is much more clearly shown in the simulation (made with SimLab Composer Mechanical) available here: https://youtu.be/tYTAA3nV_Oo. Even better visibility can be obtained by viewing the 3D PDF file which allows you to examine the mechanism from any angle and then animate it. Post-Printing When designing rotating components, keep in mind that I make the axle (pin, shaft) the same size as the hole. The holes associated with rotation are then reamed to the proper size using a hand reamer. Firstly, clean up all the excess material from printing. Then ensure that all the necessary parts, specifically those involved in rotating motion, rotate smoothly within their intended areas of operation. These components include: - Base - Driver pin - Five slot geneva (centre of base) Ensure smooth rotation is possible for each component mentioned. Lastly, position the handle stem, sleeve, and keeper handle by gently tapping them together. Secure these using 3mm x 10mm long screws. For this part of assembly use four 3-millimeter-by-ten-millimeter-long stainless steel button head cap screws although eight may also be utilised. Washers for the 3 slot genevas were incorporated into the frame in 'Frame new' which is highly advisable if desired but after all the mechanism components have been proven to function correctly.