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Old Mar 21, 2011, 12:24 PM
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Stuttgart, Germany
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I've ordered a 7.4v speed 480 I hope this is enough with a 40mm prop to propel this little tug. Will this setup work direct drive on 6V from 2 4.5Ah lead acid cells wired parallel?
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Old Mar 22, 2011, 10:39 AM
GILL
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United States, NJ, Hopatcong
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A 480 dose not have the power to push a 40mm prop, you would need at lest a 555. The 480 would get very hot with that much load. If you use the 480 I would drop down to a 25-30mm low pitch prop. The high load will reduce run time. This boat should be able to run for over 3 hours on 2-2.4 amp hour (9ah) batteries
The 480 can run very well on 6 volts, just be carful of the load. Some people like to put water cooling on the motor. During my race days I had a few water cooled. On a scale/semi scale boat this is not needed. Right now I only have water cooling on 2 of the 105 boats. 1 has a 30cc engine and the other is an electric race boat, that has cooling on the batteries but not the motor.
A fast test is to run the model for 1 minute if I can hold the motor, it's fine (below 120 deg.) if I burn my hand I change motors as it will burn it out, even with cooling.
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Old Mar 23, 2011, 11:56 AM
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Hey Gill,

I'll save the 480 for the sneakeasy im planning next, and order a 550 with cooling coil. water cooling might not be strictly necessary but if the battery is capable of 2-3 hours continuous running it might increase the motor life. What did you mean by "2-2.4 amp hour (9ah) batteries" ? what does the (9ah) refer to?
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Old Mar 24, 2011, 10:37 AM
GILL
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You said that you had 2 - 6 volt 4.5 ah batteries wired in parrell ( + to + & - to -) that will give you 9 ah at 6 volts.
Think of voltage as the size of a carburetor, the bigger the easier to run a motor and the more power produced..
The amperage as the size of the fuel tank, again the bigger the longer the run.
So a motor that draws 1 amp will run for about 9 hours, but a motor that draws 9 amps only runs for 1 hour.
Th 5 50 should not even get warm, the cooling should not be needed.
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Old Mar 24, 2011, 11:51 AM
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Quote:
Originally Posted by GILL RC View Post
You said that you had 2 - 6 volt 4.5 ah batteries wired in parrell ( + to + & - to -) that will give you 9 ah at 6 volts.
Think of voltage as the size of a carburetor, the bigger the easier to run a motor and the more power produced..
The amperage as the size of the fuel tank, again the bigger the longer the run.
So a motor that draws 1 amp will run for about 9 hours, but a motor that draws 9 amps only runs for 1 hour.
Th 5 50 should not even get warm, the cooling should not be needed.
I learned more about volts and amps in this post than i did in an hour searching the internet
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Old Mar 24, 2011, 03:50 PM
GILL
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There is a lot of knowledge on this forum.
My self I'm an R/D engineer that specialized in electro- mechanical set ups.
That and I have worked in the hobby industry on/off for almost 55 years.
I also build and repair models on the side. Over 1500 to date.
my own collection stands at 105 boats, 54 planes, 16 cars, 9 trucks, 7 helicopters, and 1 blimp. That's just the running models. Some can be seen on my site at www.jsgill.net
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Old Mar 24, 2011, 09:42 PM
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Ive been to your site before, its real nice.


If no one has said it before.

" Flat bottom tugs you make the rockin world go round!" Queen wins.
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Old Mar 24, 2011, 09:43 PM
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Originally Posted by GILL RC View Post
There is a lot of knowledge on this forum.
My self I'm an R/D engineer that specialized in electro- mechanical set ups.
That and I have worked in the hobby industry on/off for almost 55 years.
I also build and repair models on the side. Over 1500 to date.
my own collection stands at 105 boats, 54 planes, 16 cars, 9 trucks, 7 helicopters, and 1 blimp. That's just the running models. Some can be seen on my site at www.jsgill.net
Do you have skype? I would like to discuss the education and careers in engineering with you.

Thanks.
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Old Mar 25, 2011, 09:25 AM
GILL
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Sorry no skype. Even my e-mail is though work. Once I leave the office , evens & week ends, I am off line. If not I would spend too much time on line and not get the model building done.
If you check the bio on my site you will see I started my working career as a high precision assembler (2 year apprenticeship)
In junior high and high school I worked hard on my math and drafting skills. While in the Navy I started DeVry and finished when I got out. I Went to Auto Desk AutoCAD school about 15 years ago.
I will read any thing, I feel that it's the only way too learn and the more you learn the more you can do.
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Old Mar 25, 2011, 04:32 PM
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thanks for jacking my thread. I understand volts/amps i just didn't get what you were saying because of your typos. your carburetor explanation is a wild oversimplification and not really clear when you use such vague descriptions as 'more power' and 'easier to run'

but thanks its all clear now!
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Old Mar 25, 2011, 06:17 PM
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Originally Posted by jlepinske View Post
thanks for jacking my thread. I understand volts/amps i just didn't get what you were saying because of your typos. your carburetor explanation is a wild oversimplification and not really clear when you use such vague descriptions as 'more power' and 'easier to run'

but thanks its all clear now!

No problem.

It's not really "yours" More like "ours"

If he is going to teach we are going to learn, get over it.
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Old Mar 25, 2011, 07:23 PM
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well then if its ours, then perhaps you could conduct your skypey-skype chitty-chat discussion on here so we can all benefit from your exchange of wisdom.
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Old Mar 25, 2011, 10:15 PM
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well then if its ours, then perhaps you could conduct your skypey-skype chitty-chat discussion on here so we can all benefit from your exchange of bodily fluids and wisdom.
Of course. Perhaps we could all get together and have a big conference call. I'm sure you would love it!
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Old Mar 27, 2011, 11:38 PM
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I found this thread inspiring, so here is what I came up with today.



I'm starting to like these flat bottom designs, it seems like they go together quicker especially since I don't have much time to spend on them these days.
I like the placement of the motor in the false bottom section area. I can see using this technique for the Civil War USS Monitor.

I'm looking forward to seeing all your projects as you go along!
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Old Mar 28, 2011, 11:43 PM
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Originally Posted by Ford_63 View Post
I found this thread inspiring, so here is what I came up with today.

I'm starting to like these flat bottom designs, it seems like they go together quicker especially since I don't have much time to spend on them these days.

I like the placement of the motor in the false bottom section area. I can see using this technique for the Civil War USS Monitor.

I'm looking forward to seeing all your projects as you go along!
You might like to look through the designs of William and John Atkins. They have quite a few designs with a similar type underbody, which they refer to as a Seabright Skiff.

http://www.atkinboatplans.com/
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