cheers mate what i did is sprayed it with wd40 left it over night i then tool the black knob off then i found another nut so i locked both nuts together then i got a spanner on it and ive got it to move now which is great it moves free now ive re atached the black know and i can move the fence along there rail easy now what is the best stuff to clean the metal rails on both sides of the saw and the cast iron table top