Volvo 850 Heater Control Knob

A replacement Volvo 850 Heater temperature control knob (driver or passenger side). When I saw that most parts stores wanted $26 for a replacement knob, I decided to make my own 3D-printed design. The knob is not an exact match, but is fairly close. I noticed after installing and testing this version, that the knob does not fit into the control panel quite right. There needs to be a recess on the back side. I used a Forstner bit to drill out 2-3 mm on the back. I will try to upgrade the file in the future to fix the error. You can fill the slot (light guide) with epoxy or if you have a sheet of polypropylene laying around, you can use that to fill the slot and create the subtle lighting effect when the dash lights are on.