Jumbo Chicken-Head Knob overlay

thingiverse

This is a heavy-duty pointer ("chicken head") style control. I had concerns that mating the 3D-printed design directly to a quarter-inch shaft might not be strong enough, so this control is an overlay for an existing commercial control. The original control was one of these: https://www.sparkfun.com/products/9998 The "Basic knob cutout.stl" file is a plain 3D model of the main shape of the original control, with no detailed features or shaft hole. The "Basic knob cutout with hole.stl" file is the same, but also includes a cylindrical protrusion from where the set screw is located on the original control. In other words, it's the shape of the cutout needed on the bottom of the jumbo control in order to fit over the original control and allow access to the set screw. These files are available in case you want to design a new control; the cutout is already done in the main STL file, "Jumbo control.stl". The original control fits very snugly in the cutout. Some force is required to insert it. You may find it helpful to warm up the printed part with hot water before inserting the control. This control was created for the console of Organ Donor, http://organdonorproject.org Print Settings Printer Brand: Ultimaker Printer: Ultimaker 2 Rafts: No Supports: Yes Infill: 25% Notes: The cutout for the original control requires support material, but the hole for access to the set screw does not. Use a brim to help anchor the edges of the round skirt. The skirt bent upwards when the control was removed from the heated plate. I soaked the control in hot water to allow the skirt to relax into its flat as-printed shape. The support material in the cutout must be completely removed. Any remaining support material could prevent the original control from going all the way into the cutout.