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By
Tom
Hynes After
I gained a little more modeling experience, I decided to build the
second as a fictional railroad harbor tug. The hull was completed
per the kit instructions. Using
styrene sheets and formed parts, I extended the main cabins,
adding stairwells. The
high pilot house (used on real railroad tugs to see over the
railroad cars on the carfloats being moved) was scratch built to
plans in the April 1983 issue of Railroad Model Craftsman.
The stack was made from a shampoo bottle. Detail parts came
various sources, including BlueJacket Shipcrafters, and the
Lindberg kit. The
nice thing about working in HO scale is the amount of detail parts
and figures available. I
painted the tug in C&O colors and a built a Walthers carfloat
for it to push. Although
the carfloat model is really a waterline kit, it seems to float at
about the right height. Someday,
I hope to build a fully functional loading apron with approach
tracks. For
the third kit, I decided to build a Great Lakes Towing Company
tug. This was done on the Lindberg hull, which is about 20 scale
feet too long. Since
my modeling skills aren’t yet capable of drastically
modifying a plastic hull, I used it as is and tried to
position deck details to hide the fact that the hull is too long
(and too wide). I was
in a hurry to finish this model, so I actually re-used the hull
and all the electronics from the first model I built. The
GLT superstructure is from a Sylvan resin kit (kind of pricey, but
with nice detail). I
scratch built the deck and bulwarks from styrene stock.
I may someday build a second, interchangeable steam-era tug
superstructure for this model. |
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 I am using Tower Hobby two channel radios with Battery Eliminator Circuitry (BEC) for these and the other small model boats I have built so far. Everything is powered by 4 AA rechargeable batteries. These two tugs have micro servos for steering, but a standard servo will easily fit into the hull. For these and the other small model boats I’ve built, I use a modified servo for propulsion. It takes a little bit of time to modify, but they save a lot of space and weight (not necessary in the Lindberg tug but crucial in smaller models) and they eliminate the need for a separate speed control. |
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SERVO
MODIFICATION |
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1.)
I
have modified several Tower Hobbies TS-53 standard servos to make
them into motors. They
cost about $10.00 (plus shipping).
I assume that other servos can be modified in the same way.
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2.) The first step is to remove the servo arm or horn. Remove one screw and remove the horn from the splined shaft.
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3.) Loosen
the 4 screws on the back and remove the gear housing.
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(4.) Remove the gears and the pins that they rotate on.
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5.)
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6.) |
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(Picture
completed servo) Reinstall the electronics into the housing. Press a small piece of rubber tubing (or the insulation from household wiring) onto the motor shaft. This tubing will later attach to a propeller shaft of about the same size. The back cover of the housing can be held in place with small bolts or with a rubber band. The other shaft sticking out of the case is a potentiometer. This is used to adjust the dead stop position of the servo-motor once it is hooked up to the radio receiver. |
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Typical
installation This shows a typical installation. The motor shaft must be located directly in line with the stern tube. This can be done by removing the propeller shaft and looking thru the stern tube towards the motor shaft. I make a simple motor mount out of scrap styrene glued to the hull and use a rubber band (not shown) to hold the motor in place.
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STERN TUBE For small models like these tugs, a simple stern tube can be made from 1/16 inch brass rod and a 1/16 inside diameter brass tube, about 2 inches long , which is glued directly into the hull. A K&S tubing cutter is ideal for cutting the stern tube to length, although I’ve also used a razor saw, cutting the tubing and a scrap piece of rod inside it at the same time. Use a hobby knife to de-burr the ends of the tube. I used the Lindberg propeller, drilling a 1/16 inch hole into it and then super glued the shaft into the propellor. I use a light grease (Vaseline) to lubricate the shaft and then install the shaft into the tube, adding a tiny washer at each end, and a 1/16 inch collar with a set screw to hold everything together. (All parts readily available at most hobby shops). The shaft must be long enough to reach the flexible tube coupling with the motor.This
simple stern tube has no lubrication
reservoir, but the grease keeps
everything watertight, and the collar acts as a thrust bearing.
This design is only appropriate for small models. I’ve
had a lot of fun building these tug models and sailing them. It definitely got me hooked on RC boating. Right now I have
several more boats under construction and have more proposed
projects than I will ever be able to complete. Tom Hynes |
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