I finally got the Howse HD10 yesterday and took it apart. There are left and right set s of blades and the last person to put the blades on got the sets mixed up so on each side you had one blade cutting with the cutting edge and one blade wacking with the back side. I bet it was cutting like crap before the gear box went out. I bet the operator hit something with the reversed blade and instead of cutting the object the back side of the blade hit it and exploded the teeth on both sets of gears.