Propeller Question

[Adam WoodParticipant @adamwood43576]

Hi everyone…. I hope you can help me as this isn’t strictly about model boats, in a way it is though.

 I’m looking to find the best prop design driven using a flow of water (rather than an engine driving water) and I need a number of characteristics if someone can help.

I require medium torque with high RPM (not the easiest combination) which could be driven from something like the flow of a tap or hosepipe.

Thanks in advance

Adam

[John BoydParticipant @johnboyd97248]

   Try ringing propshop they advertise in MODEL BOATS .

[TelstarParticipant @telstar]

It depends what you want to drive with it.

It may be more effective to use a paddle bladed device. What you are talking about is a water turbine. These are very different to a normal prop. 

Tried to post a simpl drawing of what I mean, but don’t seem to be able to.

If you are interested give me a personal e-mail and I will forward a sketch to you

Cheers [email protected]

[Robert RyanParticipant @robertryan95520]

Can any one imform in the best way I can water proof the propeller shaft and rudder of a working model boat.

[Malcolm FraryParticipant @malcolmfrary95515]

For Robert – the best known way is to ensure that the inner end is above the waterline.  Otherwise, follow the US convention of calling such tubes "stuffing boxes" – they get stuffed with grease.  On a model, light water resistant grease as too much heavy grease introduces drag.  

Another way is to make sure the bearings are a close fit, and that the end play is minimal.  I tend to favour using a small "O" ring as a washer at the prop end.

[Adam WoodParticipant @adamwood43576]

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