Somewhere in excess of 99.9% of the time my PC 7518 router speed control stays on #5. However, I'm getting into something that needs to run at a much slower speed. But, I find, at the low speed setting, the speed is anything but constant. It appears to be hunting for the set speed; speeding up to near maximum, slowing to very slow and repeating the cycle for longer than I care to sit and watch.
Disassembled and cleaned the area of the switch and circuit board, although they were fairly clean already. My router table has pretty good dust collection and keeps the router enclosure quite free of dust and chips. The cleaning didn't seem to have any significant effect. Don't recall exactly when I got the router, but it's several years old.
If anyone else has had this problem with the PC 7518 and found a definitive and semi-permanent solution I'd sure like to hear about it before I throw US$100+ for a new speed control board down the rathole.
Tom Veatch Wichita, KS USA