I modified the handle so that it is easier to pull for a child. There are two plates in the print profile, one with the original length and one which is cut about a third shorter, again to make it easier for younger kids to handle it. This is especially true if you also use the smaller rotor:

Quarter Scale Toroidal Prop by bird2brain - MakerWorld

I also included the Fusion 360 file in case you want to modify it further.

Thanks to Kocyns for this great model!