The original knob was just a default solid chunk of plastic and thus retained the heat. (Needed an oven mitt to remove the slowcooker lid.) The new design needed to be solid enough to be stable, but allow heat to disperse.
Two files:
Slowcooker_knob_spiral - the basic knob
Slowcooker_knob_spiral_MM (recommended) - same as the basic knob, but added tree supports in MeshMixer, as the regular supports in Cura were being difficult to remove. Do not use supports from your slicer for this one - trust the trees!
Uses a 6mm bolt - seems relatively standard for slowcookers, but you may need a metal nut inside the sphere. Printed with PETG, it doesn't appear to deform in use, and can be handled without an oven mitt. (If you want to print with other filaments, I'd recommend looking up the topic of "glass transition", where your filament choice might soften.)
I used a UV Sphere in Blender, and later scaled it down on the z-axis to give it a "flatter" sphere. Deleted some planes to create windows in the sphere. Extrude/scaled the sphere to make it a mesh again, then beveled around the window to give it a more organic shape. I enabled the proportional editing tool, selected the top of the sphere, and then rotated. (There was some experiments on how big of an area to proportionally edit, as well as how much to rotate - fun!)
Added a cylinder beneath (allows fingers to grasp the sphere, without touching glass), with a M6 x 1mm thread Metric Hex Nut object imbedded into it for the bolt to screw into.
For other designers reading this - the initial extrude/scale of the sphere was not thick enough. I was going for elegance, and it needed to hold up to heat and weight.
Category: Replacement PartsThe author marked this model as their own original creation. Imported from Thingiverse.