Four flights today on 4 various capacity batteries, 300-550mA, on lighter packs it might need slight more of prop down thrust. Also testing 3 different props after cutting out new alloy spacers for precision fit to different prop addaptor. Seems like 9x4.7 is the best so far but trying hard to get 9 or even 10 by 2.5 low pitch CF ones which would be a perfect match for this set up.

Cutting out alloy sleves for perfect prop fit.

The best so far, 9x4.7 orange one.