Which propeller ??

dinsdale Fri Mar 16, 2012 2:33 am

This is just a little different from the usual, so please bear with me. I'm building a small (about 15"), light (<500gm with all the gear and fuel) airboat (swamp buggy) and powering it with a stock standard Babe Bee except for the addition of an R/C carby. Hence the question, "Which propeller" should I use? With a boat the prop never "unloads" like an aeroplane engine in a dive for instance - it's always hauling hard coz the boat will always be much slower than an aeroplane. I expect this boat will do >20kph and probably <30kph (only guess figures). To further complicate matters, the range of props I have is:-
4.5 x 4 - 2 blade
5 x 3 - 2 blade
6 x 3 - 2 blade
5 x 3 - 3 blade
The engine/prop setup will be a tractor, NOT a pusher. I'm not really after the outright fastest top speed I can get, but more like a nice flexible toy for me and my grandson to play with.
Tia
Dins