Vac-U-Boat Combat Vac-U-Gearing User manual

Combat Vac-U-Gearing™
1:144 Semi-Scale Model RC Warship Combat Gearing-Class Destroyer Hull Kit
Manufactured by Vac-U-Boat 1259 Humphries Rd. Conyers, GA 30012 [e-mail]
The Gearing Class was a series of 98 destroyers built for
the U.S. Navy during and shortly after World War II.
While no RC Warship Combat kit is “easy to build or inexpensive”, this “Beginner
Class” kit will get you started in this fascinating hobby and not only give you an
understanding of construction, control and weapon systems, but will make an
effective addition to any fleet in battling against your buddies!
This Combat Vac-U-Gearing Hull Kit Features: Tough high-impact
polystyrene hull with polyurethane-bonded sub-deck and carbon-fiber-reinforced
hull-ribs & sub-deck cross-members. The sub-deck hatch openings and the hull’s
pre-formed penetrable area panels can be removed with a hobby knife or box
cutter. Clear hatch lids & hatch tape waterproof the hull. The deck supports
realistic details and can house a forward-firing 50-round cannon or mounted as a
stern gun (not included). The rudder kit includes twin 1-1/8 square inch rudders
(Total 2.25 square inches.) cast on brass shafts with a self-aligning rudder
brackets, rudder arms, stainless steel pushrods, and e-z connectors servo.
A mini servo is included for the rudders. Servo models will vary according to
availability. The twin drive kit includes two “365” motors direct-driving counter-
rotating precision stainless steel shafts supported by Oilite® bushings in brass stern
tubes with brass couplings, injection-molded copper colored polyethylene props, 6-
32 threaded drive dogs, and prop nuts.
This Gearing-Class Destroyer is a 1.5 unit ship under the rules of the
International Radio Controlled Warship Combat Club. It can be equipped with a
“1/2 unit bilge pump” and a 50 round cannon (Not included).
© 2020 Philip Pace dba Vac-U-Boat™ 1

Now for the Warnings!
Read all of the instructions! Review and understand each step, and the one after, as you build
your boat. Don’t rush. Good work takes time.
This is not a toy! I know. It LOOKS like a toy, but it isn’t. Toys are generally safe for small
children. This boat is not safe for small children. Assembling it requires the use of sharp tools
that can cut skin, strong adhesives than can bond flesh and injure eyes, spray paints that can be
flammable and toxic, as well as batteries that can short causing severe burns or fires. Read all of
the instructions and warnings on all of the tools and chemicals you plan to use. Use protective
eyewear when recommended. USE SAFETY GLASSES! If you think you don’t have the
skills, or are uncomfortable with tools and chemicals, or just changed your mind, then pack
up this kit and return it immediately for a full refund including economical standard return
shipping. If you need some help, find a local boat club to join, check with the hobby shop
where you purchased your radio gear, or contact local RC Warship Combat clubs and
organizations for assistance. Keep your work area away from children. Even if you have no
children, when not working on the kit, keep all sharp objects and all chemicals locked away in a
safe area. You never know who will come to visit and how well they will supervise the young
ones with them.
This is STILL not a toy! Once you complete the boat and are running it in a lake, know that the
boat can injure life, limb, and property. Never touch the propeller, spinning or not, while there is
a battery inside or connected to the boat. Even if it is turned OFF, assume it can glitch and run on
its own. Never run the boat if swimmers are in the water. Don’t chase wildlife. Be careful with
rechargeable batteries. They have the ability to dump large amounts of current in a very brief
period of time if shorted, causing burns or fires. Never store the boat with the battery inside it,
connected or not. Keep your batteries in a safe place, out of the reach of children. You are
responsible for the safe use of this product. You are responsible for choosing wisely, those who
you entrust the use of the boat and radio, even for a few minutes at a lake.
Never swim after a disabled model boat!
All of these warnings are just for the Hull Kit! Add the RC Warship Combat parts and this
model is ABSOLUTELY DANGEROUS. Use safety clips in the cannon when not battling to
prevent accidental firing of a bb. Know that Lithium batteries are dangerous if mishandled,
damaged or if charged improperly. CO2 powered firing systems contain pressurized gas
that can project parts at a high rate of speed during assembly or repair. Everyone wears
SAFETY GOGGLES when in combat, repairing or testing on the work bench.
WARNING
CHOKING HAZARD - Small parts. Not for children under 3 years.
WARNING - To avoid danger of suffocation, keep plastic bags away from babies and children. Do not use in
cribs, beds, carriages or play pens.
WARNING: Brass parts in this kit contain lead, a chemical known to the State of California to cause cancer
and birth defects and other reproductive harm.
WARNING: THIS IS NOT A TOY! Once completed, this model should only to be used with the Safety
Rules and guidelines of the International Radio Controlled Warship Combat Club
http://ircwcc.com/main/home/rules/ 2

KIT CONTENTS
Hull & Sub-Deck
joined with openings
reinforced with carbon
fiber rod. Top view
and bottom view.
Pre-Trimmed Deck
2nd Deck & Deck
Components
Boat Stand and
Internal Electronics
Tray.
Internal Armor, Hatch
Covers & Balsa Skin
Cutting Template.
Hull Hardware Kit
with stainless steel deck screws,
plastic & brass 5” gun barrels, prop
alignment templates & torpedo
launcher base, 2 rudders, self-
aligning mounts, rudder arms,
stainless set screws, stainless
pushrods, ez-connectors, mini-servo,
sanding block, sandpaper, hook &
loop tape and 72 yards of hatch tape.
Twin Drive Package
with stern tubes, precision
stainless shafts, couplings, drive
dogs, prop nuts, props, synthetic
grease, motors, motor/servo
mount, couplings & template.
3

Styrene can be cut by scoring and breaking, or with scissors. The first score should be very light while
concentrating on accuracy. The second and third score is made with more pressure and will follow the first.
INSTRUCTIONS
We are ready to get started building this combat gearing hull kit. Follow the photos and captions to assemble
your boat. Read through the instructions before building. Assemble the necessary tools and adhesives on a
clean workbench or table. Keep paper towels handy to catch spills. Don’t forget the safety glasses!
To build this kit you will need: A variable-speed drill. A hobby knife or box cutter, sharp scissors, medium CA
glue or Gorilla brand super glue, Devcon 2-Ton epoxy or hobby epoxy with a 30 minute or greater cure-time. 5
minute, 7 minute, or 15 minute epoxy is not waterproof and has too short of a working time to fold in filler and
use with this model. Baby powder (100% Talc), micro-spheres or your preference as filler for epoxy. Drill bits
3/32”, 1/8”, 5/32”and 3/16”. A #2 Phillips screwdriver and a roll of painter’s masking tape. A step-drill bit is
handy for making large holes safely. Following smaller drills with larger ones will work. A Dremel Rotary
hobby grinder will be helpful to cut flats on the shaft ends.
Read ahead for each step. With hobby knives or box cutters, always cut in a direction away from nearby body
parts. Practice harder installations, motor/drives for example, without glue first to be comfortable with what
steps are needed to ensure a good fit.
When drilling styrene, drill at the slowest setting. The material is soft so little pressure is needed to drill into
it. All surfaces that will be glued with epoxy or CA-super glue need to be sanded/scuffed with 100 grit sandpa-
per to help the surfaces have a strong bond.
Bending at the score will break the plastic along the scored line. You can cut with scissors if you prefer. Either
way, any rough edges can be smoothed out with the included 100 grit sand paper or sanding block.
The stand fits the hull as shown. The right end of the stand lines up with the rear of the bilge keels on either
side of the hull. Outline the bottom of the sub-deck openings with a pencil. Use slight outward pressure on the
pencil so it will follow the outline of the recess. The mark helps you see where to score the opening. 4

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Use a 3/16” drill to round the corners by drilling next to the marked line at each corner. Do this for all 4 openings.
Score along an opening, lightly the first time and with a little more pressure the 2nd or 3rd time. If you knife
falls through the slit, tilt it sideways to pull it free. Press on one end flexing the plastic until it separates.
Continue to work the plastic with your finger until it breaks free. If it resists, then score the opening one more
time with the knife and try again.
Save the scraps. Repeat for the other three deck openings. The side openings have three sides that are easy to
mark. The bottom is located by using the side of a pencil to mark the change in the hull curve.
Make the bottom mark about 1/16” ABOVE the pencil line. Drill the four corners of each opening with a 3/16
inch drill. Score the four sides of an opening. It is thicker at the bottom line. Additional scores there.

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Tape the deck to the sub-deck/hull assembly. Set upright. Make a light line above each side cross-member
mark. At the center of the stern (back end) make a dot 1/2 inch from the edge of the deck.
At the bow (front end) make a dot centered one-inch from the tip of the deck. On the sides, mark the dot 3/8 inch
from the outer edge. Drill 3/32 holes through the deck & sub-deck at each dot. (Six holes.)**
Push the side panel inward causing it to separate at the bottom and remove it. Repeat 13 more times. Mark the
upper side of the hull at the center of the front two sub-deck cross-members to help locate the deck screw holes.
Set the deck on the sub-deck. Turn it upside-down. Look to see that it fits into the deck overhang evenly.
**You can omit screws at the rear-most crossmemeber without affecting the appearance of the kit.
Remove the deck. Drill through the center of the deck holes with a larger 5/32-inch drill.

7
Spread epoxy on the rudder mount. Press into the hull. It should look like this. Less epoxy is OK.
Check the alignment and set the hull aside for the epoxy to cure. Lay out the deck and deck accessories as shown.
Insert the #6 x 3/8 inch Phillips pan head screws. Keep them straight as they thread into the sub-deck until just snug.
Don’t over tighten. Next time, start them by hand and lightly snug with screwdriver. Use a 3/16 inch drill to drill into
the center of the rudder inset at the stern of the hull. Wallow out the hole a little so the rudder base will fit.
Remove the deck. Test fit the rudder mount. It should drop in and sit flush. If it binds, enlarge the hole a little
with the 3/16 inch drill. Sand the underside and stem of the aluminum mount and the inside of the recess.
Fold in the same volume of filler until smooth. Rub a little into the sanded area of the rudder recess.
Inside the hull, sand the top of the rudder mount recess. Test fit the rudder mount again. Mix epoxy together.

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Bend the cut line back & forth to separate. The rough edges can be smoothed with the sanding block & sandpaper.
The slight curve to the edges of the part remains and helps align the 2nd deck to the top of the deck. The 2nd
deck sits centered on the deck house. Here are comparison photos of deck parts and their location.
The 2nd deck sits on top of the deckhouse. It has a raised outline. Mark the bottom of the outline with a pencil
and use your knife to lightly score the line. Repeat scoring 3-4 times until the edges will break away.
The torpedo launcher is installed behind the first stack. One of these rectangular bases helps glue it to the deck.
This one happens to be located where an installed bb cannon’s magazine filler cap emerged from the deck.
These brass rods, plastic tube, gun housings and bases go together to make three of these dual 5-inch gun
mounts.

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Sand the gun housing back and forth on the sanding block, rotating frequently to remove the curve evenly.
Sand only until the curve is mostly gone. Before & After sanding.
to form the two exhaust stacks. This hatch surrounds the stern anti-aircraft guns (guns not included)
Consider the up-angle for your gun barrels. Mark each gun and drill with 1/8-inch drill, each at the same angle.
Trim the gun housings close. Then, lay the scissors along the side of each to trim closer. Once trimmed, the gun
housings will still have a slight curve or flair at the bottom.
These two parts form the Bridge. Troll-Captain not included. Four stack-halves are glued together...

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Trace around the raised area to guide your cutting. Cut to the line with scissors. Sand away any edges missed.
The sanded base has smooth turned-down edges. Sand the inside bottom of the gun housing. It is a good idea to
put a piece of foam inside the housing for flotation in case your gun gets shot off of the deck.
Gun housing and base ready to glue. Put superglue around the inside edge of the housing. Set the base on a flat
surface that the glue won’t damage. Don’t forget the small piece of foam.
Press the gun housing over the base and hold for 10 seconds. When picked up, the bottom of the gun housing
should look like this. Repeat for the other two guns. Cut a 3/8-inch long piece of plastic tube.
Separate the three gun bases. Trim away the edges as shown. Turn over and trim closer but don’t cut the raised area.

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Scuff one side of the rectangle. Put CA on the raised areas on 2/3rds of the underside of the torpedo launcher.
Attach the scuffed side of the rectangle and hold 10 seconds. Get the two bridge pieces.
Mark the tube 1/8” from the end. Put a tiny amount of CA around the end of the tube and insert 1/8” into the gun.
As you insert, make sure they are aligned and parallel to each other. Mark around the torpedo launcher and trim.
Sand the edges and bottom to a smooth finish. Turn over & scuff the underside. Cut out one rectangle.
Sand 1/4 inch of the end of a brass rod. Slip the 3/8” piece of tube over that end. Add a little CA around the end
of the rod and press the tube over the rod until even with the end of the brass rod to form a gun barrel. Make 6.

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Trace the edges with a pencil and trim with scissors. Use a hobby knife to get the inside corners.
Trace around the stern anti-aircraft gun placement. Trim with scissors. Add a tape-handle, and sand against the
sanding board, rotating frequently to remove the curved edges left by the scissors.
Scuff in side the line for the glue to adhere. Put CA on the bottom edge of the pilot house. Align and press in place.
Like the gun housings, use the sanding block to sand away the edges left by the scissors. The thinner pieces are
easier to hold with a handle made from masking tape.
Sand or scrape away any bits inside the walls of the bridge railing. Set the pilot house as shown, centered and
touching at the rear of the inverted bridge. Trace a light pencil line around it.
IMPORTANT - If you are installing a bow cannon, do not glue the pilot house to the bridge yet. OK to glue
the bridge to the second deck without the pilot house. The cannon may go under the pilot house.
REAR

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Holding at the base, with light pressure, sand the bottom flat to where the sides of the stack begin to curve
inward. Take your time. Check frequently to make sure it sits straight on a flat surface. Before & After photo.
Insert a piece of foam and put mixed epoxy inside the stack on the foam and along the inside of the glued
seam to strengthen the stack and make it float. Set aside for the epoxy to cure.
Tape one side of a pair together. Open the 2 halves. Put a thin layer of CA along the mating surface of one half.
Fold together and align the seam. Hold for 15 - 20 seconds. Secure with tape and let it dry at least one hour.
Get the four stack halves. Trim with scissors. Cut off the bottom just below the curved edge. Make a tape handle.
Easier to hold the stack half for sanding. Sand to a flat surface. Don’t press too hard. Before & After sanding.

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Apply CA to the bottom of the stacks and glue to the stack bases on the 2nd deck. Orient them as shown.
Apply CA to the top of the deck house raised areas. Set the 2nd deck on the deck house centered and aligned.
Hold in place 10 seconds. Press all surfaces to bond the CA. Sand the mating surfaces of the deck fixtures.
The base for the pilot house, round gun mounts, the rear anti-aircraft gun placement and the top of the stack bases.
Optionally, you can add some foam inside the 2nd deck to help the boat sink upright in battle. Sand the raised
portions of the top of the deck house. Sand the corresponding areas under the 2nd deck. Important - Leave out
any foam in the 2nd deck if installing a bow cannon as large holes would be drilled there.
Inside the hull, add filled epoxy to reinforce the stems of the rudder mounts as shown. Use a bent wire to reach around
to distribute the epoxy. Attach the deck to the hull with the center 4 screws. The deck and hull are curved. Gluing on
the 2nd deck with the deck attached to the hull will help preserve the curve of the deck to match the hull’s curve.

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Trim the marked edges of the boat stand and the Combat Gearing Hull Kit is complete. If you
have the complete kit with the twin motor drives, the installation of the hatches to the sub-deck
and the internal armor panels will be discussed after the drive installation directions. The shipping
box makes a great temporary storage box for the hull if trimmed as shown.
The accessory tray is installed with hook & loop to make it easy to remove for drying or working on the electronics.
There is room under it for a layer of ballast, and a water channel.
For the guns, tape will help you align the round piece under the gun with the round mount on the deck. Don’t
install the gun where you plan to mount your bb cannon later. After CA cures, drill 5/64” hole through deck into
gun base. Insert an included #4 x 1/4” stainless screw to help hold gun in place when hit by enemy bb’s to help
avoid embarrassing gun loss in battle.
IMPORTANT - If installing a bow cannon, do not glue the #2 gun to its base.
If installing a stern cannon, do not glue the #3 gun to its base.
The torpedo launcher points toward the bow of the ship. The pilot house front edge lines up with the base under it.
Note the raised walls of the bridge railing hang over the sides of the base under it.

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Prop templates can help you align the prop shafts to the hull and rudders in a scratch-built drive system. Glue to
flat plastic scrap. Drill 1/8 hole at center & sand to the outer ring. Mount at the center of the threaded part of the
shafts temporarily while gluing the motors and stern tubes in place. The inner ring is the prop’s 1-inch diameter.
The space between the rings is the clearance you want between the prop and the hull.
With this kit, the motor/servo mount will align the prop shafts pretty well without using templates. You can just
install the two props and use them to make sure you have things aligned and proper spacing between the props
and the hull. Set the motors on the motor mount as shown.
Once water gets into most servos, they will die. If yours starts to show symptoms or erratic behavior, unplug it
immediately and plan to open it up and dry the interior at the end of the day. You may be able to salvage it.
Vents
open at
sides.
The included servo may be factory water resistant. If not, before installing the Servo, it can be made
water-resistant: Clean off any oil or dirt on the servo case. Scuff the servo case with sandpaper. Paint over
the case seams and case screws with two coats of a conformal coating, dope or some nail polish. Put a dab of
filled epoxy where the wire comes out of the servo. After the motor installation, squirt some stern tube grease
around the output shaft under the servo arm. The Motor/Servo Mount will accommodate the Traxxas 2065
waterproof mini servo.
Now is a good time to solder a wiring harness to your motors while they are out of the hull. Next to each brass
tab, there is an embossed + and - to indicate the positive pole and negative pole of the motor. Shorten the female
JST connector to about 2-1/2 inches. Strip the insulation at the ends. “Tin” the wires by applying solder to them,
even if they are “Pre-tinned” silver.
This is one of the smallest classes of ships. The motors only draw an amp or two in normal use. Heavy wires and
100 amp speed controls are not necessary. Weight is a serious factor to properly ballasting the ship. Consider
small inexpensive 10 amp Electronic Speed Controls that use red JST connectors. 20AWG wire is better.
22AWG wire is OK. Less breakage with thicker wire. Buy only JST connector pairs that have silicone insulation
and you will have less breakage near solder joints. Wire both motors the same, red to + and black to -. The ship
has counter-rotating props. One of the motors will run reversed. Make reverse “Y” connector at your ESC where
the polarity of one motor connector is normal and the other is reversed. This way you only need one wired spare
motor to serve either side of the drive because the ESC’s plugs determine which one is running in reverse.

Push the couplings onto the motor shaft. Install and tighten the motor-side set screws. Remove the shaft set
screws. Mark the coupling holes on the shaft with a fine tip felt pen to locate where you will grind flats on the
shafts. Flats prevent the set screws damaging the shafts which would make them harder to remove for
maintenance or repair. Use a Dremel tool to grind 2 flats on each shaft where the shaft was marked. Scrape off
any burrs along the edge of the ground area with a hobby knife to prevent binding in the coupling. Do not
attach shafts to the coupling yet.
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Install the motor clamp and screw. Tighten only until snug. Install the servo with the wire running toward the
stern of the ship as shown. Drill 1/16” holes at the dimples in the mount and attach with the two screws included
with the servo. Insert shafts fully into motor coupling & lightly tighten one set screw.
Tin the motor tabs. Connect them by holding the tinned wire to the tinned tab and apply heat to melt them together.
As viewed from the stern, the right prop turns clockwise and the left prop turns counter-clockwise. With threaded
drive dogs and prop nuts, they can unscrew when a shaft is turning clockwise. To prevent this, add some thread
locker or some epoxy to the front 1/4-inch of threads as you screw on the drive dog. Do not put thread locker on
the prop or prop nut. If the drive dog can’t rotate, then the prop won’t rotate either. Screw on the drive dog to the
end of the threads. Push or screw on the prop until it contacts the drive dog with the slots lined up with the tabs
on the drive dog. Screw on the prop nuts. They will seat the props into the drive dogs. Tighten until snug.

Loosen the shaft set screws and remove the motor mount and two shafts & stern tubes. Scuff the outside of the
stern tubes to help them bond to epoxy. Inject grease into both stern tubes. With the sanded stern tube end pointed
toward the propeller, insert a shaft into each to the shaft center which will push out excess grease. Clean off any
spilled grease from the parts or on your hands. Grease will lubricate the shaft and prevent water entering the tube.
You want the shaft ends approximately 1/8 inch in front of the rudder leading edge. Set the hull on the stand.
Insert the motor assembly. Connect the shafts to the couplings but don’t fully tighten the set screws yet. Align
the props to the rudders and check for clearance between the blades and the hull. Inside the hull, mark the
position of the motor mount on the hull with a pencil at the front and rear of the mount. This marks the area
you need to sand plus once glue is applied, returning the mount to these marks will assure that the props are in
the correct position relative to the rudder.
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Sand the slots for the stern tubes and re-install the shafts & tubes. Sand the underside of the motor mount. Do not
sand the servo or the servo area of the mount.
To avoid binding or excessive friction in the drive shaft, the brass stern tubes should fit fully into their hull
journals (angled depressions in the hull). The hull is pre-drilled for the stern tubes, but the openings will need
some adjustment if the stern tubes are up on the end when inserted like this. Once the top of the hull opening is
trimmed, the stern tube will lay down into the journal.

The final location for the stern tubes is with only about 1/8-inch or less protruding from the hull journals. Keep
the epoxy off of the shafts. Mix two 1-1/4” puddles of epoxy and add filler.
While holding up the inside shaft end, use a rod or narrow brush to force epoxy under the stern tube into the hull
shaft journal. Rotate the tube to distribute the epoxy. Clean any grease off of your fingers to avoid contamination.
Brush filled epoxy on the underside of the motor mount. No epoxy near the tunnel to avoid the servo wire. Set
the motor assembly into the hull at the marked location. Hold in place. Attach shafts aligning the flats with the
coupling set screw holes. With the boat on the stand, insert the rudders into the rudder mounts for reference.
Visually center the two props to the rudders. The motor mount will slide a little left or right. Check the
position of the stern tubes. Note the servo is approximately centered to the keel groove in the floor. Check the
distance from the end of the prop shafts and the leading edge of the rudders. When everything is lined up, let
the epoxy cure. Check as it cures to make sure nothing moved while the epoxy was still liquid.
19

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Find the double-ended rudder arm in the servo packet. Drill the middle holes on each end of the arm with a 1/16-
inch drill. Insert an ez-connector into the hole. If it is a tight fit, then remove the ez-connectors and drill again to
enlarge the hole a little. With the plastic keeper snapped in place, they should rotate easily, but not too loose.
Before attaching the servo arm to the servo, we need to
“Center” the servo. This can be done with a servo tester or by
connecting it to your radio system and powering it up.
Connect the servo lead to the #1 channel of your receiver.
Turn on your transmitter. If you are using an ESC with
“Battery Eliminator Circuitry” (BEC), the ESC supplies
power to the receiver when you attach the battery to the ESC.
(No need for a separate battery for the receiver.) Connect the
ESC to the receiver and battery. Turn on the Transmitter, then
turn on the receiver. (You may need to consult your radio
system’s manual or ask for help from your fellow captains.)
With the system on and working, center the radio’s steering
stick and center any adjustment wheels or switches to center.
This centers the servo. Attach the arm. If it is a little angled,
then turn it around and it may fit straighter. Press in place and
attach the small screw from the servo accessory packet.
Grind a 3/8-inch flat on the leading edge of the rudder shafts facing forward. Sanding off the sharp corners of the end
of the shafts will make it easier to insert into the rudder arms. Put a little grease on the shafts near the rudder blades.
This is the electronics tray. It fits into the 2nd bay from the bow. You may not need all of it. It helps you lay out
your electronics. Best to attach it later to the ballast or hull with pieces of hook & loop for easy removal for
drying or working on the electronics once you have designed the layout and location of the internal parts. It holds
the receiver, switches, ESC, firing boards or other components. Open the rudder package and servo packet.