I am thinking of making a de-thatcher in the form of swinging blades which will be operated by my 5' cut Woods mower. Specifically, I plan to take a 1/4" x 3" x 20"(approx) steel bars, drill holes and mount de-thatcher springs (maybe torsion springs) via bolts thru the holes and cut a 1.5" hole in the end of bars and replace the mower blades with these "dethatcher" blades. Do blades like this exist or is it a crazy and dangerous idea? All sorts of dethatchers on on the market but I have never seen this idea in practice. The rotational speed is 540 rpm - too fast for de-thatching?