Novice question on propellor choice

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ianrichards
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Novice question on propellor choice

Post by ianrichards » Fri Mar 10, 2017 3:43 am

I've now got my boiler and Stuart 5a engine sourced for the 15 ft Selway Fisher Rose that I'll be starting to build soon and am now seeking guidance on propellor choice.
Knowing nothing on the subject I am open to any advice.

I appreciate that I am looking well ahead, but at this moment in time I am snowed in in a guesthouse on the Annapurna Circuit in Nepal with nothing to do, but at least I have wifi and can dream of being back in my workshop in Cornwall (UK).

Any advice greatly appreciated and a web link or two would be great as well.

TIA
Ian
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cyberbadger
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Re: Novice question on propellor choice

Post by cyberbadger » Sat Mar 11, 2017 4:53 am

Check this thread on the FAQ subforum:
Propeller Pitch - what it means and choosing the right one

My Nyitra is a different hull, size, and engine - but she is running 18" diam x 24" pitch. I wish I had a larger diameter, but it's fine for now.

Here is a propellor calculator that dampfspieler posted in the above thread..
http://www.rbbi.com/folders/prop/propcalc.htm

-CB
ianrichards
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Re: Novice question on propellor choice

Post by ianrichards » Sat Mar 11, 2017 9:56 am

Many thanks, will read and digest
Ian
cyberbadger wrote:Check this thread on the FAQ subforum:
Propeller Pitch - what it means and choosing the right one

My Nyitra is a different hull, size, and engine - but she is running 18" diam x 24" pitch. I wish I had a larger diameter, but it's fine for now.

Here is a propellor calculator that dampfspieler posted in the above thread..
http://www.rbbi.com/folders/prop/propcalc.htm

-CB
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Lopez Mike
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Re: Novice question on propellor choice

Post by Lopez Mike » Sun Mar 12, 2017 10:46 pm

Interesting that the calculator will not accept r.p.m.s below 500. Maybe when working a 5A hard but never with my 3 x 4 single.

I'll maybe fudge the numbers and divide by two or some such scheme.
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