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Making
- Drive Shafts!
With
Brass - Tubing & Rods
( Designed for
R/C Workboats & Ships )
"Not
Meant For Use in Speed & Race Boats!"
This Idea
is very simple and uses
the - "Basic Three
Brass Tube - Building Method" of construction. Each of the required
three different sizes of Brass Tubing, must fit ( One inside the Other ), like a Telescopic Antenna.
The size of the tubing = used, depends on what your model needs? To
determine this, look at your Wheels
= PROPELLERS .... "What diameter of "Drive Shaft" do they
Require?"
By measuring the diameter of the shaft hole in the prop, you simply choose the correct diameter of brass tubing or
rod, to make the
"Drive Shaft", by working up a couple sizes.
CRITICAL
ITEM
= NEVER
- OMIT THESE! ...... ( The
2 - 1/2" Long - SLEEVE'S ) installed in each end of the Housing
are critical items. They must be installed for this
drive shaft system - to operate properly.
THE SLEEVES .... act as Bearings & Grease Seals
= Or Spacers,
between the "Drive Shaft" itself and the Housing. If
omitted, the drive shaft will overheat - as it turns inside the housing, swell-up
& seize tight and thus ruin the drive. Brass expands under
heat & friction, so the 2 sleeves reduce this effect to absolute minimum's
and must be installed. They also provide a space ( Or
Gap ), for
the lubrication grease,
which acts as the shafts = water proofing seal, between it and the Housing.
The length of the Drive - Itself, makes little difference ( Short Or
Long ), the system works and is easily made to virtually any length required. And
used "With Or Without" a
Gear Drive, but should always be equipped with a flexible motor to shaft = coupling,
like the Dumas Motor/Drive Couplings. NOTE...... To fill the
drive shaft = with grease, simply purchase a small "Hobby Syringe" and fill
it with ordinary "Axle Grease", or any general purpose "Automotive
Grease" like those used to to lubricate ball joints .... Never Use"
= Heavy Oils or Petroleum Jelly, in this drive shaft system = THEY
DON'T WORK!
Drive Shaft Making - Parts List
#1 ... ( 3 ) Lengths of Brass Tubing ... K
& S brand - for example, available from most any hobby shop or hobby supplier parts catalog.
( Sizes of tubing required, depends on diameter of your
already purchase - Propeller and its -- Drive Shaft Hole Dia.
Then work - up, two more sizes in tubing to create the 2 Sleeves and the Shaft
Housing ..... That's It! )
#2 ... ( Solder = 60/40 Rosin Core -
Electronic Solder, Plus cleaning Paste & Brush and a Damp Sponge to clean
your solder Iron or Solder Gun - Tip.
#3 ... Lube Grease, can be purchased in "Throw Away"
tubes for hand operated Grease Guns .... Purchase at Wal-Mart or Local - Auto Parts ....
Common gun grease, is what mechanic's use to lube fittings on your car /
truck or tractor- drive shafts and other grease fittings.
#4 ... ( 1 ) Hobby Syringe,
filled with Grease to lube your shafts. Keep it handy in your r/c tool box,
and periodically lube drive shafts, after several runs, to insure their well
greased and water sealed - at all times!
REQUIRED
LUBRICANT= Ordinary - Automotive Grease
or Axle Grease ..... "Use
No Other types or Petroleum
Jelly or Oils - inside this drive system. Only grease like
those used to lube a car
/ truck or farm machinery, purchased from any auto parts or Wal-Mart
Store. And be sure to purchase a
small "Hobby Syringe" to fill
with grease and keep it handy - in your tool box, to keep your shafts lubricated
periodically. Just insert the syringe - down the "Grease Tube" on
the drive shaft, and add a small amount of fresh grease, after a few runs, to
keep the systems water tight!
Break-
In Method.....
Use a bench vice to hold the new drive shaft
- firmly. Then use a spare dc motor connected to a battery - to turn
the drive shaft, after you have filled the housing with fresh - Grease,
using the hobby syringe.
As the shaft - turns and spins, for the very first time, the new grease will instantly start to
look - dirty. And may begin to ooz - from each end of the housing.... RELAX,
That is Normal. But as soon - as it stops oozing out, insert the
syringe and add a few more drops of grease - as the shaft is spinning, so it
fills any voids with more grease. Meaning any open space the grease
didn't reach, when you first assembled the parts. Once
the shaft is broken-in, by running it for several minutes in time .... "Re-
lube again and clean off - any excess grease from the outer - housing, prior to installation
into
the hull. ( Use "Paint Thinner or Acetone"
with an old
rag ), then rough sand the housing.
in areas where it enters or
exits - the hull, to insure the glue - used, will hold it - firmly without any Hull - Leaks! )
INSTALLATION
- OF NEW SHAFTS ..... Mount
the Shaft into your hull with heavy set epoxy glue, designed to withstand water
to insure it
never vibrates - loose or leaks. Here I suggest everyone use of J-B WELD EPOXY
WELD ..... This glue is purchased at most any - Auto
Parts Store / Wal-Mart or Hardware store. Its
a 50/50 Epoxy mixture that withstands constant moisture and
doesn't come loose in automotive use, under water or high heat conditions. Other
brands of epoxy like hobby brands of "50/50 Hobby Epoxy in 5 to 30 minute types
as most use in this hobby, don't withstand moisture or constant vibration and it
will easily comes Loose or break down! ...
So
Be Warned, if ya use that sort of glue = and it fails ...
Don't say - I Didn't Warn Ya!
Shaft Building
Tools - Required
#1 ... Dremel Tool & Bitts
= Cut-off Wheel, Sanding Drum / Etc. ... to cut & shape parts.
#2 ... Solder Iron
( 25 Watt ) or Solder Gun ( 50 /100 Watt ), plus solder gun- tip cleaning equipment
and tools, or a small - Propane Hobby - Torch.
#3 ... 60/40 Rosin Core -
Electronic Solder and Soldering Paste to insure good welds on parts.
#4 ... A small
piece of 200 Grit - Sandpaper,
to polish brass tubing - at all points to be soldered, prior to applying solder
and final assembly.
#5 ... Bench Vice - to hold
parts, as their assembled.
#6 ... Spare -
Dc Motor & Battery / Jumper Wires & Drive Shaft - Couplings ), to break-in
the New System before its installed into the hull!
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GEAR DRIVES
Some Modelers
- Like Them, Some Don't!
..... But Their all important in a model, when you have trouble slowing it down
to a crawl during those close-in maneuvers and lets face facts here = Workboats
ain't No Speed Demons. They also help
keep your dc motors - Running Cooler Too!! So the few
shortfalls that gears - have, are worth the hassle in My Opinion.
And you'll find several links to sources of gears & belt drives on my
Hobby Links Page. NOTE! .... Plastic gears are less noisy,
than metal ones, but a belt drive is the smoothest system to use, provided
you have the space to install them? So it depends on how much
you want to spend, since plastic gears or most usually cheaper
then metal or brass gears. Besides - Metal Gears make a lot of
noise, which can cause RF radio interference sometimes.
Picking
A Gear Drive
The
best brands or types of Motor - Gear Drives, will have "Nylon Gears" to reduce
further shaft or motor noise! Metal Gears are always much-more
noisy, and also cause a great deal RF or radio control interference.
Here again, a "Belt Drive" is even better,
because their smoother running and also easier to install, but usually cost more. Whether purchased or Made
= All Scratch, both systems
will reduce rpm motor speeds and also further reduce the
current loads on the motor, battery and speed control to more manageable
points. So that means longer runs, and everything stays cooler
and the battery lasts a lot longer. The ratio of the drive, meaning
its two measurements from Engine to Shaft in turn speeds, can basically range
between 2 to 1, to over 6: to 1 ratios, which is shown as 6:1 in the systems
information. Here, the usual ratio's most often used are
3: to 1, meaning the motor turns 3 times, to ever single turn of the propeller.
Unless it needs more reduction, like in the case of a "Paddle Wheeler"
for example. These gear driven system, usually report the
shaft speed at somewhere close to 100 Rpm's, which is about true speeds for a
real steamboat - paddlewheel. So a drive that provides about
120 Rpm's, might be a good choice, or maybe one that says it puts out - 85 Rpm's
as another example in trade off's, depending on what voltage its going to be
operated at. Here, something which provides 120 rpm at 12
volts, won't work to well at 6 volt, or 7.2 volts, because the drive is to
slow. But a drive motor that runs at 200 rpm, at 12 volts, may
be perfect at 6 volts, while just a little fast - at 7.2 volts, so it will work
- Right?.....Yep!....Yer getting the Picture Now!
_______________________________________________________________
RUDDERS - They Ain't All
The Same!
The average
person seldom conciders - rudders, all that important to a vessel, since all
boats have to have them - Right! .... Well its a bit more complicated then you
think. Rudders can be very sophisticated systems, and even
high tech, on even a small Workboat in some cases. And once
you see and understand the unique ways a rudder can be shaped - to do some very
odd things.... Like a Wing does on an airplane. It all starts
to make a lot of sense and workboats becomes even more interesting - in how
unsual and unique - these boats, really Are!
Tap Photo To Enlarge
The Contrguide - Rudder by St. Louis Ship
Probably the most sophisticated rudder - ever designed, which operates just like
a trim fin on aircraft - wings. Only in towboats, it cancels
out the propellers - constant attempts to swing the boat in the same direction
as its prop - Is Turning. With
each 1/2 section having a slightly different - Pitch, these rudders steer
slightly more-in "One
Direction", depending
upon which side of the hull - its designed to work. Meaning there's Port
&
Starboard version of Contrguide's, which are used on
Single & Twin, as well as Triple screw boats and at one time - were also
found on Quad
Screws. These rudders completely cancel out the boats tendency to constantly want to turn, or torque, in the same
direction
as the propellers are turning - Going Ahead. Here, the lower point of these
rudder, is actually offset from the upper portion, by a few
degree's. The lower section, canceling out the propellers -
torque, and allowing the vessel to steer more easily. On a twin screw - for example, "If One
Engine Goes Down", the pilot can still continue to steer a straight coarse, without
constant steering - corrections, on the remaining engine. So
these rudders cancel out - prop/hull torque
effects, and also save fuel and make it far easier for pilots = To Steer. Once you realize
this is the realm where you
fight cross winds and cross currents - in shallow waters, these rudders make a
real difference and a lot of sense.
Note .... Vessels equipped with Contrguide Rudders, don't have "Pintle Bearings"
to hold or brace the lower part of the stern rudder on their kort nozzles. These rudders are designed to "Break-off",
if damaged, leaving the upper portion still intact, so boats can continue with
only reduced steering effects.
Two
Types of Rudder Systems!
FLANKING
& STERN....
Both systems are individually - operated, on real boats, but in this case, via
R/C Radio Control in Model boats, we can choose several ways to achieve this
effect. But first, you need to understand rudders - on
these boats, which are not typical, or like those used on other
vessels. Because towboats typically have 3 rudders = per shaft
..... And they're are a lot of - Single Screw's out there - so remember this
fact. A Twin
Screw typically has a total of 6 rudders - in all. And a Triple Screws, or Quad Screw
towboat will have a total of 8 to 12 rudders - Respectively.
Such large numbers of rudders does sounds - Rather Confusing, and difficult to imagine
for some modelers. But their critical parts in what makes
these boats - So Unique!...... "So They Gotta Have Them to be - Real + TOWBOATS!!"
Tap Photos To Enlarge
Barn Door - Rudders = are
used on just about all types and sizes of towboats, but usually are found
on "Line Haul & Long Haul - class vessels. The term - Barn Door, naturally describes their massive
size, along with the ribs or braces, which support and stiffen their massive
size. When compared to other styles of rudders, these monsters do look like
sort of like = barn doors, often measuring over 12 feet in length and 8+ feet, in
heights. Regardless of
whether their = Flanking or Stern mounted, they're the most typical style
of rudder used on big boats.
Tap Photo To Enlarge
Paddle
Board or Box - Rudders = are smaller versions of rudders,
like the ones used on mid-size to smaller class - towboats, and/or other
vessels. A very simple design, like a smoothly shaped = Paddle design,
showing little or "No Braces". Also used on large
boats, but still called - Paddle Rudders, which differ in design from "Barn-Door"
rudders.
_______________________________________________________________
Break-Off
or Break-Away = Rudders
( See Also = Barn Door
& Contrguide Rudder Details - Below )
As strange as this sounds, rudders and their steering shafts, can be designed to completely break-off, or have sections
- that break -off, if their hit or damaged. Considering towboat
hulls are constantly being - run aground on shallow rivers, this idea makes lots
of sense. Building such features into a rudder, is accomplished by
making the rudder post - itself, in 2 sections. Naturally, the upper section of
these rudders - is made from solid metals, but the lower section is designed to break off - If
Struck By an Object. "Break Away - rudders", allow
a vessel to continue service, but with reduced steering effectiveness.
These rudders are welded with - Overlapping Joints, Or Bolt-On Sections, that create such
rudder effects using soft-bolts. Highly unique, and
towboats were
the 1st - to use them, which later led to these rudders being introduced into other realms of ships and
boats.
Proper
Rudder Positions - ON HULLS
I simply can't stress this - enough, because rudders improperly positioned on a hull,
make their effect on the boat, almost = USELESS!
Tap Drawing to Enlarge
This drawing shows - just how critical the position
of "Flanking Rudders", behind the propeller -
IS. And how
effective they will operate and steer the vessel, if positioned within the diameters of the
propellers - Thrust lines. So you should take notes - on this, when
installing rudders on
a model towboat = Or Any Hull.. NOTE - The details and
mounting information - in this drawing and position your models rudders - accordingly, even if
its equipped with "Kort Nozzles",
because its critical, in how effective your steering - will work, while running
- In Reverse!
Tap Drawing to Enlarge
Diagram of Typical - Flanking
& Stern Rudders
This is how the component parts - go together, inside a
model towboats - hull. The Above Left - Drawing, shows each
steering system is operated with 90 degree "Bell cranks".
Note the Short - "Hull Sleeves" or Housings that go through the hull
and protrude- the hulls finish, for a "Water - Tight" seal.
The Hull Sleeve - is just a short piece of brass tubing, which is the next size- Up,
in diameter tubing, from the rudders post = Rudder Shaft. The rudder
post, extends above
the hull waterline - inside the model. And also extends higher
to allow the 90 Degree - Bell Cranks, to be attached for rc
operation. The rudder post, is made from solid brass rod -
"Usually" ( Or Tubing ), that's notched ti fit the rudder plate into
position. Common 60/40 electronic solder can be used with a
solder gun to assemble these parts, but the brass must be buffed - with
sandpaper or a Dremel tool to allow the solder to weld their parts
together. Note .... Some
Flanking Rudders, do have notches to allow them to swing past & over the drive shaft = itself, with touching.
And the rudders may also have "Stress Braces", or "Ribs"
that increase its strength. These can usually be made with angled
brass, soldered into position in the proper points. or by using strips of brass
to make the upper & lower skid plates on rudders.
Parts Required
- Solder Gun Solder = 60/40 Electronic Type or Silver Solder &
Solder Paste Sandpaper Dremel Tool
& Bits Brass Sheets, Tubing & Rods NOTE!....
Brass or Copper Materials can be used to make these parts, available from K
& S Metals ( See Hobby Links Page ). If Copper = is used,
it must be polished - before soldering, then smooth all parts with sandpaper or
Dremel tool - for finishing.
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Last Updated On 06/30/07
. With
Fueled By 
Email
Old River Bill
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