Plastic for cooling sucks.

I miss the days of being a repeat customer of any brand of any car, truck, tractor, mower, tool, because the last one worked so well, lasted beyond expectations and was often replaced because a buyer just "wanted a new one* with the one in service probably still working just fine. Now a days it's gotta be replaced because the existing one is plum wore out/"shot"/busted and because replacement parts aren't available or else if they are, a silly knob is priced at 80% of the cost of a whole new "whatever".
I remember back when I lived at home if I dropped dad's drill and broke the switch I could go down and very cheaply buy a new switch and fix the existing drill.... Much cheaper than a whole new drill would cost. Not any more! Chuck the whole works in the trash and buy a whole new unit.