Stirling EE-9248 Robot Vacuum Rubber Brush Assembly

myminifactory

Well, that was a thrilling challenge! Sometimes it's crystal clear that various manufacturing methods have unique capabilities and constraints, especially when attempting to replicate something for 3D FDM printing! This part, which is a rotating rubber brush that had broken in my vacuum cleaner, features a rigid core, a metal pin seated inside a bearing and suspension bushing, and flexible rubber fins on the outside. Not the most obvious target for a 3D printed alternative, but we can't let that stand in our way! Most crucially, this spare part needed to be easily printable, without supports, and without requiring any special printer features beyond printing flexible filament for the blades themselves. Several design considerations arose: * The rod core must be designed to print with layers running parallel to the long axis for maximum strength. * The flexible blades need to be printed with layers perpendicular to the long axis also for added strength. * Blades must be secured in place so they can't move relative to the rod core, or else they'll shift under load during operation. After a few design adjustments, the final product took shape: * A hexagonal central core for easy printing on its side * Sleeve-style blades printed in flexible filament and slipped onto the rod * Blades designed as segments for easier printing * Tight press-fit flange end-pieces printed separately * Gradual vertical steps for printability without supports while maintaining functionality * Incorporation of a cavity for a 10mm M3 bolt, which, when screwed all the way in, leaves it protruding exactly the right length to accommodate the bearing. There you have it - more incredible things we can accomplish with 3D printers!