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How fast do Model sub props spin? - Maxon gearmotors for subs?

R/C Submarine modelers

Postby lvlender » Sat Jun 21, 2003 1:32 am

Hi Fellas,

What screw RPM is recommended to push a medium-size sub? The 1/96 AKULA is 47" long witha 5.25" beam. My reason for asking is I just found some Maxon geardrive motors are on eBay. 1500 RPM at 12V DC, 900 RPM at 6V DC,and 175 RPM at 12V DC speeds are available. The motors can be used with lower or higher voltages and the output speed will be proportional. The output shaft is 3mm dia. Might be a good propulsion choice if I can match the output RPM of the motor to your recommendations.

Kevin Savage
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Postby TK-7642 » Sun Jun 22, 2003 4:00 am

You can look up Raboesch brass props on the internet. You will find a chart with all prop types and sizes, with their max rpm of cavitation for different diameters.
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Postby Robse » Sun Jun 22, 2003 8:47 am


There's some info on propellers and rpm, prices, sizes etc. on the following link:

I have researched this a bit, and have noticed that most modellers apperently uses a 3:1 gearing, bringing the propeller RPM "down" to app. 4000 -> 5500 RPM. I have not yet tested this on my own sub, and I'm really looking forward to see how the drive train will handle such speeds.. I have an idea that it is not needed at ALL to go that fast.. time will tell.
Yours Sincerely, Robert Holsting, Denmark
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"Never be afraid to try something new; remember that it was amateurs who build Noah's Ark, and professionals who build the Titanic"
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