This was designed not to require supports, with a .4mm nozzle. The bottom of the knob has a whole designed for a M4*6*6 brass insert. One of the best ways to insert the insert is with a soldering iron tip, press the insert in until it's flush or slightly below the plastic and then you have a perfectly useful knob. No supports were required, when I printed it, but depending on the machine/slicer supports may be necessary.