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Author Topic: Cygnus Driveline  (Read 1408 times)

Netleyned

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Cygnus Driveline
« on: July 30, 2013, 12:45:47 pm »

I have a Cygnus GM33 hull and it came with a MFA 919D 2.5/1 geared motor.
I have fitted a 50mm four blade brass prop and would like to run off 6V SLA's.
I need loads of ballast so batteries provide it with a fairly good run time.
This set up gives a no load speed of 3000 rpm.
Would I need to go to a 6/1 gearbox or would another motor on direct drive
be more suited?
Thanks in advance for any comments/suggestions.


Ned
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unbuiltnautilus

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Re: Cygnus Driveline
« Reply #1 on: July 30, 2013, 01:55:04 pm »

Sounds fine to me. The motor is a low drain type, at 2.5:1 reduction that 50mm prop should be just fine. With the 6:1 option you would be looking at a prop more like 60mm to 70mm in diameter to get any meaningful thrust out of it.
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Netleyned

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Re: Cygnus Driveline
« Reply #2 on: July 30, 2013, 05:04:28 pm »

Thanks for that UBN.
Thought it would be about right, but as sails are my
normal 'motive power' it is nice to get confirmation
from an Expert.

Ned
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Smooth seas never made skilful sailors
Up Spirits  Stand fast the Holy Ghost.
http://www.cleethorpesmba.co.uk/

unbuiltnautilus

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Re: Cygnus Driveline
« Reply #3 on: July 30, 2013, 05:15:22 pm »

Thanks for that UBN.
Thought it would be about right, but as sails are my
normal 'motive power' it is nice to get confirmation
from an Expert.

Ned

Where? Who? What?
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Listen politely, nod approvingly, then do what you want, works for me!
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