RC Groups

RC Groups
    uk.rec.models.engineering
        propulsion for a large scale rc model

#1 Matthias Broersma Jun 13, 2004 09:00 PM

propulsion for a large scale rc model
 
i was wondering what i could use as propulsion for a 9'-10' catamaran.

what kind of rpm and torque do i need? can i use those gardentool engines?
weight would not be the problem...or do they have a low rpm?

what about waterjet? if i understood well i need an engine that runs a
pump... what specs do i need in this case?
any links?


thanks.
matthias



#2 Steve Blackmore Jun 13, 2004 09:01 PM

Re: propulsion for a large scale rc model
 
On Sun, 13 Jun 2004 23:03:28 +0200, Matthias Broersma wrote:

> i was wondering what i could use as propulsion for a 9'-10' catamaran.


Sails?

> what kind of rpm and torque do i need? can i use those gardentool engines?
> weight would not be the problem...or do they have a low rpm?


Choice is small prop,fast rpm. Large prop, slow rpm. Torque means
nothing, especially when you ask a question like "What sized engine will
power a boat"

> what about waterjet? if i understood well i need an engine that runs a
> pump... what specs do i need in this case?
> any links?


Google?

Post your displacement, LWL, expected speed and I'll find my old marine
engineering books and tell you how much power you need.

--
Steve Blackmore

#3 Gary Cavie Jun 14, 2004 09:02 PM

Re: propulsion for a large scale rc model
 
In article <Bi3zc.35766$G%.14451@tornado.fastwebnet.it>,
matthias.broersma@fastwebnet.it says...
> i was wondering what i could use as propulsion for a 9'-10' catamaran.
>
> what kind of rpm and torque do i need? can i use those gardentool engines?
> weight would not be the problem...or do they have a low rpm?
>
> what about waterjet? if i understood well i need an engine that runs a
> pump... what specs do i need in this case?
> any links?
>


If you try asking your question on rec.boats.building, someone on there
sometime back pointed me to a site with an online calculator which will
fill you in with the details. I no longer have the site bookmarked, but I
remember vaguely it had something to do with an engine marinising
company.

Sorry it's a bit vague!

Gary


All times are GMT -5. The time now is 01:30 AM.