I am currently building a skimmer (Dave M will be very familiar with the type). I propose to mount the motor as a pusher on the single pylon. To minimise clutter I was thinking of a single rudder, mounted centrally behind the motor. Most skimmers/airboats I have seen have two rudders, but do I really need two? Any thoughts? Thank you Steve
Hi Steve The two models of your skimmer we have in our club both have two rudders. Others have built from scratch but all have moved to two rudders as this gives the best control. Our lake is large and perhaps on a smaller lake one rudder may be OK.
I would have thought that, every thing else being the same, 2 rudders will probably, maybe, give twice the turning effort, possibly. Does the position of the rudder(s) in relation to the thrust of the prop affect the effectiveness of the rudder though? A single rudder immediately behind the centre line of the prop will have the max air flow at the top and bottom of the rudder blade, so presumably behaves differently to twin rudders on either side of the centre line where the max thrust would be in the central part of the blade. (I think!) The other option is of course suck it and see, and change it if needed.
Hard to believe I know, but I am not an aerodynamicist!
From what I have seen of Airboats (including several in Florida many moons ago 🤔) two rudders are predominant. Offset Twin rudders seem to be smaller, not so long front to back and single rudders huge and seem to have been used only on very early versions of airboats. Must be a reason why they evolved to slimmer twin rudders. My guess is better response with less braking effect and consequent loss of speed in turns and / or less effect from cross-winds. Whatever, have fun with it, but watch out for the alligators 😲😉 Cheers Doug 😎 PS can highly recommend a visit to an alligator farm 😲😲
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Young at heart - slightly older in other places 😉 cheers Doug Grant me the Serenity to accept things I can't change, the Courage to change things that I can, and the Wisdom to know the difference!