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Old Jan 12, 2013, 04:55 PM
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United States, ME, Castine
Joined Jan 2013
14 Posts
Help!
1/200 Oasis of the Seas

Im building a 1/200 scale model of the Oasis of the Seas by Royal Caribbean. Its going along great so far I have a few questions..

I have (3) 400 sized motors, do you think this is enough power at 8.4V to get the ship moving at about 3 mph? it weighs in around 25lbs and is 69" long with a 3" draft

Second, I bought a 12V big lead acid battery to help with the ballast, how can i knock the power down to 8.4V? resistors?

third, i was planning on using the traxxas EVX-2 marine ESC to power all three motors, i was planning on splicing one output to power 2 motors and leaving the 3rd motor to have its own source. I was also planning on setting them up in a parallel series.

Finally, i want to install a bow thruster, how exactly are these set up? do i need to have a seperate battery to power it or will it be sent from the esc?

Thanks,

Jake
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Old Jan 12, 2013, 05:12 PM
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Joined Oct 2004
82 Posts
Check out this thread. This fellow in Belgium has done it all ! If you can't find his E-mail let me know.

http://boards.cruisecritic.com/showt...1531861&page=2
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Old Jan 12, 2013, 05:48 PM
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PDX, OR
Joined Dec 2002
10,113 Posts
I think the three 400 series motors would be enough power.
Not sure there is any reason to knock the power down from 12 to 8.4 volts.
I ran a pair fo 400 motors on 12 volts for 5 years, and only changed them out to
get more torque.

Bow thrusters can run directly off your main power if they are rated fro 12 volts.
Some are only rated for 6v, and "complain" horribly if run too hot.
They can be switch left or right thrust using micro switches, or powered using
a dedicated ESC.

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Old Jan 12, 2013, 07:27 PM
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United States, ME, Castine
Joined Jan 2013
14 Posts
the motors are only rated for 7.2-8.4 volts, do you think that they would be okay? they are brushed
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Old Jan 12, 2013, 08:17 PM
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Australia, WA, Garden Island
Joined Nov 2010
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Quote:
Originally Posted by MerchantMariner View Post
the motors are only rated for 7.2-8.4 volts, do you think that they would be okay? they are brushed

I believe Umi Just answered your question above

Quote:
Originally Posted by Umi_Ryuzuki View Post
I think the three 400 series motors would be enough power.
Not sure there is any reason to knock the power down from 12 to 8.4 volts.
I ran a pair fo 400 motors on 12 volts for 5 years, and only changed them out to
get more torque.

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Old Jan 13, 2013, 05:36 AM
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Blackpool, Lancs
Joined Feb 2006
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If the motors are run over voltage, a lot depends on the loading. I have had a 6 volt 400 burn out in an hour or so on 8.4, on the other hand, with a much lighter loading, a similar one went for years. You can get 5 pole 400s ( = 385 ) in various voltages, but if you already have the motors the best solution that is going to work is to use an 8.4 volt battery for them, and use the 12 volt SLA to power the lighting and any effects fitted. Unless you use LEDs for the lighting, it could easily use more power than the motors.
Resistors would work losing the 4 or so volts at whatever current was being pulled, but would need some trial and error ( element from a dead electric heater or hair dryer cut down springs to mind ), and would do a great job of heating the interior of the boat.
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Old Jan 13, 2013, 02:18 PM
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Wisconsin
Joined Jun 2007
1,909 Posts
I would agree with mfr02 in that more info is needed to determine if those motors will work. There are so many 400 sized can motors that it's not a simple answer. At work, we use two different 400 sized motors. We refer to them as fast and slow, but compared to the hobby motors they would be slow and slower.
You have more than enough room in a 69" boat for bigger motors, so why not use a set of 500 sized can motors made to run on 12 volts and let them loaf along at low amps to drive your boat around?

Dave
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Old Jan 13, 2013, 02:31 PM
life is a beach
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thessaloniki-greece
Joined Sep 2008
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Can't you use a connection between the motors that will share the battery's power?
For example two motors in one 12v battery can take 6v each.can someone tell us if this is possible for sure?
Or in your case 3 motors which are 3x8.4v powered by 2 12v gell cells.if this is possible you will also have extra weight for your ballast...
Any pictures of your model please?

Bill...
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Old Jan 13, 2013, 04:07 PM
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i cant use a bigger motor because im using azipods so the 400 are the biggest size that will work to make them look accurate. i will post pictures once i clean up the fiberglass a bit and pull it from the plug.

anyone have an opinion as far as the traxxas evx-2 esc that i was planning on using?
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Old Jan 13, 2013, 05:23 PM
"Take the Cannollis"
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Lake Martin ALABAMA
Joined Feb 2006
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I'm sure one of the engineering profs at MMA would be glad to advise re any electrical questions if the answers given here confuse you.
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Old Jan 14, 2013, 10:45 AM
Ragbagger
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St Simons Island Georgia
Joined Jan 2010
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At 69" long and balasted to water line she will weight, what 40lbs? She is going to move a lot of water at scale spped. 400's sound light to me.
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Old Jan 14, 2013, 12:07 PM
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United States, MI, Macomb
Joined Nov 2006
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Quote:
Originally Posted by MerchantMariner View Post
i cant use a bigger motor because im using azipods so the 400 are the biggest size that will work to make them look accurate. i will post pictures once i clean up the fiberglass a bit and pull it from the plug.

anyone have an opinion as far as the traxxas evx-2 esc that i was planning on using?
Traxxas EVX and EVX-2 are fine for ESC. You could probably run both motors off one ESC. 400 sized motors will not give you much control or performance. Is there a possibility to go brushless? If you need ballast, you could use the lead acid battery, but I would be going Lipo.

You really need dual EVX-2 Esc's and a pair of Traxxas 775's if you ask me.
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Old Jan 14, 2013, 04:30 PM
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United States, ME, Castine
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getting some bigger motors that will operate at 12v just fine, btw everyone there will be 3 motors not 2 so hopefully everything should be fine.

I am planning on splicing the evx-2 esc so i can run all 3 on the same esc!
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Old Jan 14, 2013, 06:58 PM
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pics

Name: model deck 7.jpg
Views: 118
Size: 73.4 KB
Description: this is the plug up to deck 7 before fiberglassing, it looks different now after more work, the bow had some filling to be done along with the stern and sanding in the middle

Name: model azipods.png
Views: 215
Size: 187.9 KB
Description: azipods that i will be using

pics of the hull up to deck 7 before fiberglassing and editing of the bow and stern

Azipods that will be using look like this
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Old Jan 14, 2013, 07:40 PM
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United States, MI, Macomb
Joined Nov 2006
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Quote:
Originally Posted by MerchantMariner View Post
getting some bigger motors that will operate at 12v just fine, btw everyone there will be 3 motors not 2 so hopefully everything should be fine.

I am planning on splicing the evx-2 esc so i can run all 3 on the same esc!
The EVX-2 is designed to handle (2) 540 sized motors or one 700 sized motor.

It's a beafy 180 amps, but 3 motors could be too much.

I would suggest using a third 60 amp ESC and use a "Y" harness off your reciever. That's if your using (3) 540 motors.

You might want to do a little research on a three motor setup thay may have been used in a PT-109.

There are recievers with multiple throttle ports. You may need this to control 3 or more motors.
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