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View Full Version : How to get a Twin screw lifeboat turning on spot


Declan Barry
Sep 19, 2004, 03:11 PM
Hi all..

I'm just getting started into the electrics of Model Boats and was
wondering if anyone knows of a speed controller that will allow one
engine to be put in reverse wilst the other is going forward. I'm
current building an RNLI Mersey Class lifeboat and I know from
experience - having served on one - that turning on the spot is done
by making one engine go in reverse and the other forward and
controling engine rpm - depending on what way you wish to go.

Anyone any ideas or am I being too critical. I don't was to use a bow
thruster as I wish to keep to scale and authentic replication.

Regards

Declan Barry


Regards

Declan Barry

Kevin R
Sep 19, 2004, 07:11 PM
there are lots of units out and about that do exactly this but all you need
is a elevon mixer http://www.vanns.com/shop/servlet/category/type/298 for
$12.99 connect the elevator channel to the throttle channel and the aileron
channel to the rudder channel along with a y lead, then two normal speed
controls will give you the control you need along with your normal rudder
"Declan Barry" <dpbarry@barryweb.co.uk> wrote in message
news:j2jrk01hql7r94h7rdap7ac0libpm6ff4k@4ax.com...
> Hi all..
>
> I'm just getting started into the electrics of Model Boats and was
> wondering if anyone knows of a speed controller that will allow one
> engine to be put in reverse wilst the other is going forward. I'm
> current building an RNLI Mersey Class lifeboat and I know from
> experience - having served on one - that turning on the spot is done
> by making one engine go in reverse and the other forward and
> controling engine rpm - depending on what way you wish to go.
>
> Anyone any ideas or am I being too critical. I don't was to use a bow
> thruster as I wish to keep to scale and authentic replication.
>
> Regards
>
> Declan Barry
>
>
> Regards
>
> Declan Barry

William
Sep 19, 2004, 09:11 PM
"Kevin R" <dontemailme@ntlworld.com> wrote in message
news:y0n3d.999$jO1.333@newsfe3-win.ntli.net...
> there are lots of units out and about that do exactly this but all you
> need is a elevon mixer http://www.vanns.com/shop/servlet/category/type/298
> for $12.99 connect the elevator channel to the throttle channel and the
> aileron channel to the rudder channel along with a y lead, then two normal
> speed controls will give you the control you need along with your normal
> rudder

That's a cool idea, and I didn't know such things could be had
so cheap. I'll have to look into it myself.

I'm in the planning stage for large model of the U.S.S. Olympia
and, looking at the decidedly un-balanced rudder (essentially all
aft of the pivot point) I was thinking of rigging something to let
the props provide some steering action to improve
maneuverability. (And as a backup in case the rudder linkage
snaps - although I'm thinking I may have to use a worm drive to
the rudder shaft to get enough torque; pushrods are right out.)

-Wm

Kevin R
Sep 20, 2004, 05:11 AM
"William" <all_replies@news.group.please> wrote in message
news:php3d.12326$1d6.2661@fe1.texas.rr.com...
> "Kevin R" <dontemailme@ntlworld.com> wrote in message
> news:y0n3d.999$jO1.333@newsfe3-win.ntli.net...
>> there are lots of units out and about that do exactly this but all you
>> need is a elevon mixer
>> http://www.vanns.com/shop/servlet/category/type/298 for $12.99 connect
>> the elevator channel to the throttle channel and the aileron channel to
>> the rudder channel along with a y lead, then two normal speed controls
>> will give you the control you need along with your normal rudder
>
> That's a cool idea, and I didn't know such things could be had
> so cheap. I'll have to look into it myself.
>
> I'm in the planning stage for large model of the U.S.S. Olympia
> and, looking at the decidedly un-balanced rudder (essentially all
> aft of the pivot point) I was thinking of rigging something to let
> the props provide some steering action to improve
> maneuverability. (And as a backup in case the rudder linkage
> snaps - although I'm thinking I may have to use a worm drive to
> the rudder shaft to get enough torque; pushrods are right out.)
>
> -Wm
and even if you have 3 props you can still use one just connect the centre
motor with a y lead to the throttle and when stationary it should not move
but the outer ones will, I have seen specialist units for quite a bit more
but as far as I can see they do the same job but are marked up "marine" and
they put the price right up
Kevin

BigJ3650
Sep 21, 2004, 09:11 AM
Its simple to get one engine to go in reverse and one in forward but
it depends if you want the two motors to be running together or
independantly.

to run them together...i dont know

to run them independantly then run it as a 4 channel 1 channel for one
motor so you have channel 1 for motor 1 and channel 2 for motor 2 then
channel 3 for the rudder (the rudders you should have together) and
channel 4 for whatever you please.

J