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Big Momma Maryland needs some power!

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Big Momma Maryland needs some power!

Old 01-22-2005, 12:18 AM
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faufresh
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Default Big Momma Maryland needs some power!

Well, i'm scratchbuilding a 1/144th scale USS Maryland battleship and it's 54'' long with a final weight of approximately 25-30lbs. My question is this, what size motors to get?! I was planning on having the outer two screws static while having the two innard screws active. This will help facilitate in turning right? Also, which ESC would be best suited for this kind of task? I like the concept of having adjustable speeds. Thanks in advanced!
Old 01-22-2005, 07:23 PM
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Control
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Default RE: Big Momma Maryland needs some power!

Ok, i can help here. I built a 1.55m Frigit and it had a car battery in it. I ran it with two speed 600s in series, meaning they each got 6v. That was fine for power but wasent so reliable as if one slowed down the other got full 12v and went sky high. You might want to consider a couple of geared 550s, they would do nicely, but you have got to quet them down abit. As for turning, thats what bow thrusters are for, however finding one for my new 2.2m Destroyer (with 2 car batteries) is a different story. Electronic speed controlers are a problem when you start getting this big. I have a macanical one on my 1.5 meter one, but im guessing this wont suit you. For my new boat which has 2 x 700 turbos at 12v each, im going to use an aero ESC and then use a complex series of relays to reverse it ( desighned by simoncarter1, if u want a circuit diagram i can give it to you). But there are ESC on the market that can do 40A at 12v with reverse if its what you really want, but it will set you back some $$$. Hope this is of some use to you,

Woods767
Old 01-23-2005, 01:10 PM
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Default RE: Big Momma Maryland needs some power!

If you can find some good surplus PITTMAN motors you will be set.
I ran my 78"(2 meter) light cruiser on two 12 volt pittman motors. On one 7amp battery it could almost run all weekend. Easily last all day, and much faster than "scale" speed.
Direct drive, no gears. I sold the boat, other wise I would give you the serial numbers.

I run two 24volt Pittman 8314b703 in my 56" (1.4 meter) destroyer.
Again, direct drive, and it runs most of the day on one 12v 3amp battery.
These motors come out of hospital centrifuges when they fall out of spec.
Usually they are garbage, so the BioMantainence guys just give them away free.
I also have some Pittman "MU8423A003 14 VDC 08-26-99". Once again, direct drive, and way too much power for my 52" ferry boat. It runs about one hour on a 12v - 1.9 amp battery.


Here is a quick search for "Pittman motors" on e-bay. "****" = "e b a y" in the broken link.
[link=http://search.ebay.com/pittman-motors_W0QQsofocusZbsQQsbrftogZ1QQfromZR10QQcatref ZC6QQftrtZ1QQftrvZ1QQsadisZ200QQfsopZ1QQfsooZ1QQco actionZcompareQQcopagenumZ1QQcoentrypageZsearch]Pittman Motors on e-bay[/link]

The top one in these three look like the pair I had in my cruiser.
http://cgi.ebay.com/ws/eBayISAPI.dll...869333059&rd=1

Just put in "e b a y" for the ****'s in both the link...
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Old 01-24-2005, 12:25 AM
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faufresh
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Default RE: Big Momma Maryland needs some power!

Thanks gor the great responses you guys! I'll be looking for some Pittman motors on E-bay for the next week now! I was preferring direct drive and now that i've read this, it's a sure thing. Are there any links for the ESC's that you folks do have? whether it be electrical or mechanical, i'll take it. Wealth of information here.
Oh and one more thing... I was surfing round the net and found this nifty site. http://www.swampworks.com/Catalog-Hardware.html It's got all sorts of goodies on it and was wondering if one of these puppies would do it for me. The convenience of having everything in one spot is fantastic. Again, thanks in advanced!
Old 01-24-2005, 08:38 AM
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Default RE: Big Momma Maryland needs some power!

If you guys know anyone in the market for a large warship, please send them my way. I have a partially completed 1/48 scale WWII destroyer, Fletcher class, with install motors, speed controls, and most of the superstructure is built. I have lots of money in it, and don't want to ship it, but it would make someone a nice project if they are looking for a boat. It is from the Scale Shipyard. Work is good. Don't want to advertise it, but I will sell it to someone who is interested. I just don't seem to have time to finish it up.
Tommy
Old 01-24-2005, 03:48 PM
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Default RE: Big Momma Maryland needs some power!

I recon this ESC should do the job http://www.hobbypeople.net/gallery/159102.asp
Old 03-07-2005, 11:05 PM
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Default RE: Big Momma Maryland needs some power!

Are you going Big Gun or Fast Gun? Different speeds there. Under Big Gun, the USS Dallas, similar size and weight, does great on Speed 400's with gearboxes and an MTroniks Marine ESC at 6v. You get much more efficiency with a gearbox. For Fast Gun, you might want to consider a Traxxas Villian gearbox with appropriate motors for the higher speeds they alloow, but then you might want to go to a Proboat ESC.

Gearboxes have much more torque, preventing weed-up as well.

Note that the 1/144 Graf Spee did fine on 2 385's wired in series on a 6v system, and had to have the speed limited by the ESC with a radio EPA in Big Gun with direct drive. In Big Gun, it is not that hard to get a ship up to scale speed - rarely do you need the big motors. My little 22" freighter was trotting along at 25.7 knots at the last battle (finally got rid of that grease clog, I am thinking, as I was usually getting 18 knots) with a Tamiya Solar Motor 02 (the short, fat one), which is basically a cassette player motor.

Knowing the application (Big Gun vs Small Gun aka Fast Gun) helps determine what you need almost as much as the size, displacement of the ship.

Wreno
NTXBG

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