Closeups of the blade bolt modification. The blade holder hole was tapped for a 4-40 thread, and 4-40 bolts were threaded up from the bottom through the blades and into the holder, with a #4 washer under the bolt head. A regular 4-40 nut forms a locknut on top. The blade tension is easily changed and the blades are easily removed, without having to use thread lock compound. I am currently using steel bolts, but nylon would work as well... the blade stresses are carried by the blade holder sleeve and not by the bolt.