Cargo ship scratch build
 

[img]file:///C:/DOCUME~1/Owner/LOCALS~1/Temp/moz-screenshot-8.jpg[/img]Hey guys, I have never built a scale boat and only one RCboat. I have a low budget but got a really good idea. I'm not sure if its been done before but it probably has. Iwant to make a really really big cargo ship. I'm thinking 8 feet long. Iwant to take a huge block of styrofoam and cut/sand the block like carving a sculpture to make the hull. Then I will coat it with fiberglass cloth. Would this work? I could take another block of styrofoam to make the helm...structure thing on top of the deck. This would lift off to access the engine. I plan on using the cheapest electric engine I can find with home made water pick ups, homemade rudder.. I want to make as much of it as I can myself. I am going to make a picture on paint to show you what the hull might look like.

Thanks!

PSHow much would a very cheap electric engine system cost? (engine, esc, and whatever else is needed)

RE: Cargo ship scratch build
 

You could use an old cordles drill motor for power,nothing like a free motor. I used them to power my ORCA and SS MINNOW.

RE: Cargo ship scratch build
 

Awesome idea! I unfortunately don't think we have a drill thats ready to be put to sleep..

RE: Cargo ship scratch build
 

ok sorry pic is hard to see... Basically this is it:
top picture:
yellow area is very narrow and gray area is the wide, rounded hull part
pink line shows how the rounded part will swoop down
those dimensions are estimates of how big each part should be

bottom pic:
yellow is solid foam
blue line shows what part will lift off to access inside of hull
green is water pickup
red is rudder and drive cable obviously
I plan on gluing in some blocks of wood about the drive cable to make a shelf.. a piece of balsa will be set on the block of wood to make the shelf where the radio box will lay.. this will make a straight shot to rudder while making drive still accessible... this setup should allow there to be a straight shot for the stuffing tube and drift shaft with no strut... should go straight out the back I don't understand how the throttle servo/esc/electric engine works... explanation is much appreciated.. thoughts on this? (sorry if my design is confusing)

pictures should give a rough idea of my plan hopefully allowing someone to find areas that will surely cause major problems
thanks for the help!

RE: Cargo ship scratch build
 

Looks like a great idea and a cool project! Be sure to post pics as you go along.

A few things to consider for an 8-foot model boat:

One or two cordless drill motors may not provide enough power. They are often high-RPM motors that would need to use some sort of gear reduction unit to avoid burning them up. Your drawing looks to be a direct drive, so if you want to go as cheap as possible, look for high torque, lower RPM motors that you can directly turn the propeller(s) with. Check the "All Electronics" company website. They usually have a lot of cheap DC motor types and sizes to choose from. The $15 electric scooter motor looks interesting :D.

I've seen a few huge r/c boats out there running with old trolling motors, eliminating the need to buy a propeller, stuffing tube, drive shaft, etc.

It's going to need a lot of weight strategically placed to get the hull to sit in the water correctly and not be blown around by wind. Large sealed gel cell batteries are good for weight. Plus you'll have pleanty of amps to feed the motors. At 8-feet, you could also put a deep-cycle marine battery in there, but keep in mind some require maintenance and can leak fluids and fumes.

Water pickups require speed. Not sure this boat will go fast enough for a water pickup to work without some kind of pump. But if you can find the right motor(s), you won't need auxillary water cooling anyway.

Just by it's shape alone, a long and lean boat like this may be hard to steer with just a single rudder behind the prop. Some modelers use multiple rudder setups or bow thrusters (small propellors mounted inside the front of the hull to push it right/left) to overcome this.

Most importantly have fun and don't get discoraged if everything doesn't come together on the first try.

RE: Cargo ship scratch build
 

Thanks dauntless! we have an old trolling motor I might try,,, I'm just having fun thinking of this project right now... action is nowhere near soon to come... thanks for the reply though!

RE: Cargo ship scratch build
 

Some large cargo ship builds...

http://www.greatlakesmodeling.com/museum/museum_1.htm

http://www.zeeslepers.com/mailline/h...l_line_01.html

RE: Cargo ship scratch build
 

I have tried making large light-weight boats and a major concern is stopping it from warping!!. I am thinking of using a hollow cored bi-fold door from Lowes, they come in several widths 12", 15", 18" etc, are very light and cheap (especially second hand). Then foam blocks on top and minimum underneath to give it stability and prevent wind flipping it over. Should be able to make nearly 8 foot long but still light enough to handle easily. Any thoughts???

RE: Cargo ship scratch build
 

I build using floating dock pieces of blue foam. What you want? comes in 1' x 2' x 8' long. Cost? + $60.00 local lumber yards. in NJ.
Great fpr boats. The hull can / should be CAREFULLY hollowed out to save the long pieces for deck parts. I use caulk gun sizes of Silicone Rubber. Always really tape the used end carefully. Get the CLEAR only.

You wil DEFINATELY need plastic keels to stop the wind blowing the boat sideways all the time. Make the keels deep enough to protect the props & rudders. 2 are better.
Any size car radiator fan motor will work. Junk yard Make sure it runs on 2 brushes. Add a small used car battery from the junk yard & a ESC done.
Remember FOAM is super light. Put the big piece in the water to see how high it floats. 1' high piece lightned willsink 1" to 1.5"

Rich