balencing a type iv, is it necessary to use a harmonic balencing technique or is old school triple beam good enough? Options

[funk]

I have a mech who says I should put the internals on a balancing machine. It costs 225$ I have read books saying you can use a small grinder to grind the heaviest rods, pistons ect.. then weigh on a scale for balancing to within a 1/2 gram this mech thinks a balancing machine is far superior and well worth 225$ Any advice? and if I did use a dremel on the rods and internals how do you balance a fan??I couldn't find any literature?thanks just for kicks I also spoke with a retailer/mechanic who states that type four motors don't need to balanced??