My second pyramide I have no picture off, it got smashed during storage long time ago. It was of medium size of the three, and had this principle blueprint (just a googled photo for illustration, not my work):
Two sickels, their upper endings meeting kind of heart-shaped and holding the rotating central rotor shaft in the mdidle. Had the size of a cut-open, halved Halloween-gourd.
I hated to saws the rotor blades. They are made of balsa, and boy did that stuff splinter easily along the cutting edge. Maybe the sawblades were not ideal, but those I had were what I had.