Originally Posted by
f3a05
Dunno if it's possible on your contra setup,but there's often enough length on the prop shaft, to allow a washer to act as a spacer,to push the spinner back plate forward a bit.
Again, if it's possible, a simple domed prop nut at the front end replaces the entire spinner (and is convenient for quick changes of prop when experimenting with different props).
There is the opportunity to use a larger spacer on the rear shaft but that required me to go back to Debowski to get them so, as I needed some extra grip between the drive washer and prop I used a couple of sheets of emery paper that provided the improved grip on the prop and provided the spacing increase I was after! However, I eventually went back to a very slight down thrust and used the increase in incidence to do the job I was after. I think I'm almost there with the incidence at 1.2 deg ish.
Adam provides 3D printed spinners and these are retained by the prop nuts so no multiple 2 mm screws to undo when you want to remove the prop. As regards experimenting with props I don't do that with carbon props! I took Adam's recommendation of 23x20 front and rear. That provides loads of power, 3,600 w with a fresh pack at wide open throttle! I might drop down to 22x20 in due course.