Download and read the Adhesives & Fillers 101 pdf file. The Fittings Kit! 2. Marking Off, Test Fitting, and Punching holes! 3

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1 THE MOEBIUS SKIPJACK SUBMARINE CONVERTION TO RADIO CONTROL Instruction Manual Download and read the Adhesives & Fillers 101 pdf file The Fittings Kit! 2 Marking Off, Test Fitting, and Punching holes! 3 Assembling the Aft Dive Planes & Rudder! 4 Cutting the Hull for the Z Type Configuration! 6 Drilling and opening Upper Hull Holes! 7 Preparing And Assembling The Sail! 9 Installing the Sub-driver Foundations! 13 Welding the Lower Hull Together! 14 Assembling the Upper Hull! 16 Installing The Sail! 18 Installing the Torpedo System! 20 Page 1

2 The Fittings Kit A stern planes and yoke B rudders and yoke C after Sub-driver foundations D Sub-driver shock absorber E forward Sub-driver foundation F nest transverse bulkhead G nest keel piece H torpedo tube nest foundations I torpedo muzzle bulkhead J propeller shaft foundation K propeller L propeller shaft, bearings and coupler M hull rudder hole blanking discs N sail plane operating shaft bushings O hull stand hole blanking pieces P Sub-driver restraining strap foundation Q sail planes and bell-crank R sail-to-hull mounting foundations S sail plane bell-crank shaft retainers T sail plane bell-crank U mechanical fasteners V after radial flange W forward radial flange X upper hull securing screw and foundations Page 2

3 Marking Off, Test Fitting, and Punching holes to the tight radius at that point of the stern. On the inside of the two stern quarters, grind flush the raised flanges of the former rudder operating shaft bores. Do not permanently glue anything else together yet, though some of the below shots show assembled hull quarters. From the center of the blanking discs, measure 1/4" aft and drill a new 1/8" diameter rudder operating shaft hole, top and bottom hulls. Out of the box, the hull is broken down into four large hull sections or quarters, two upper hull quarters and two lower hull quarters. Take the two stern hull quarters, identify the 3/16" diameter resin blanking pieces (M)-hull rudder hole blanking discs & (O)-hull stand hole blanking pieces) and insert and CA each disc into a rudder operating shaft hole, leave a bit of the blanking disc standing proud of the hull. Sand it to contour Glue in the two oblong resin (O) Hull Stand Blanking Pieces into the two oblong holes, one in each of the bottom hull quarters. Page 3

4 Assembling the Aft Dive Planes & Rudder Check the fit, within the hulls stern, of the stern planes and rudders, as well as (J) Prop Shaft Foundation. Using 1/16" diameter brass rod, (not supplied) make two Pushrods, 7" in length, each with a Z-bend at one end. One Pushrod makes up to the rudder bellcrank, the other Pushrod makes up to the stern plane bell-crank. Install Klik-on Magnets to the ends of the Pushrods. (see right) using CA adhesive. Make up the Pushrods to the yokes to check them for operation. Take the two Propeller shaft foundations and, after grinding away the radial and longitudinal raised braces at the stern of the two stern hull quarters, test them for a tight fit. Keep the l o w e r a f t e r h u l l q u a r t e r Propeller Shaft Foundations in place for the next step, the dry-fit of the running gear and control surfaces. Install the two Rudders and two stern planes as seen here. Check for non-interference of control surfaces and yokes Page 4

5 through the full travel (not to exceed 35-degrees left/right and rise/dive). Note how the intermediate drive shaft runs through the center of the rudder yoke and over the swingarm of the stern plane yoke. Make the Intermediate Drive Shaft. Use an 8 1/4" length of.014" wall thick, 7/32" outside diam. either brass or aluminum tubing with half a Dumas nylon dog bone inserted into each end. Each dog-bone pinned to the shaft with a transverse length of 1/16" brass rod peened at each end. Work out how much dog-bone half projects past the tube as you integrate the running gear with the SD. Page 5

6 Cutting the Hull for the Z Type Configuration A Z Type type break between the two hull halves provides for quick access (only one screw at the stern holds the hull halves together), is strong, and is less susceptible to flexing than a simpler horizontal break that runs completely around the bow and maybe even the stern. Take the Forward lower hull and Upper stern Hull in hand and put the other hull sections aside. Forward lower hull: Identify the second radial stiffening frame from the bow. Set the compass at 3" inches. Place the point into the right-angle union between hull and frame, mark a radial line into the inside of the hull quarter denoting the bow cut line. Do the same for the Stern upper hull. That datum frame is the one at the leading edge of the horizontal stabilizers. Set the compass at 2 1/4" It's much easier to follow the cut line if it's on the surface of the hull quarter, so now you have to transfer the inner cut line to an outer cut line. Plug in a 100 Watt light bulb, and us it to back-light the interior of the hull quarter so you can see the internal radial inked in line through the translucent plastic. Pencil in cheat marks to the surface of the hull over the line you see through the hull. After enough points are put down to get an accurate indication as to the lines true form, lay down some masking tape, it's edge at the cheat-marks, and ink in a proper cut line to the outside of the hull using the edge of the tape to guide the Sharpie pen point. Remember, cut off the stern of the Stern upper hull, and cut off the bow of the Forward lower hull. Don't screw up! And don't cut these pieces off till later, we're just marking things off at this point. Use a Japanese saw to make these cuts. Check twice and cut once! Page 6

7 Drilling and opening Upper Hull Holes Mark then drill or grind out the openings on top of the two hull quarters. Here are two upper hulls, the top one has its holes opened up. The bottom unit has just been marked off as to hole shape, location, and size. Use new drill bits spun at low speed. Styrene takes to the bit well, keep the pressure light as you punch through. The indented round depressions on the sides (upper and lower) of the hulls indicate drill size to use. For holes larger than 3/32, start the hole with a 1/16" bit, this serving as a pilot-hole that better directs the cut of the larger bit that follows. When using high-speed cutting bits, work in short, low pressure jabs. Punch out 7/16" diameter holes in the centers of the six ballast tank vents on the forward deck flat. Do the same for the four ballast tank vents on the after deck flat. Don't touch the four big Main Sea Water holes on the after lower hull quarter after quarter hull section, those will later be covered by Photo Etched gratings. The following hole locations are now marked off along centerline on the forward upper hull quarter. Measurements are taken from the projecting nib, marked 'datum' on the above photograph, just aft of the forward deck flat: 1. A square hole who's forward transverse line is 3/16" from datum, and after transverse line is 5/8" from datum. The longitudinal edges of this inked in hole are 1/16" inboard of the troughs that accept the indexing lips at the bottom of the sail assembly. Later the lower sail plane bell-crank gear will project through this hole /4" aft from datum is a 3/16" hole that will pass the snorkel head-valve tube down into the hull. If you use the 3.5 Sub-driver unit, the SAS snorkel foundation piece will be used as a marking stencil to indicate where you'll drill 1/16" holes that accept the selftapping machine screws securing that foundation atop the hull, under the sail. See picture. 3. 6" aft from datum is the first of three 1/4" holes that vent air in and out of the hull, under the sail and exhaust fairing. 4. 8" aft from datum is the second 1/4" vent hole 5. 10" aft from datum is the third 1/4" vent hole Page 7

8 The many square holes you have to punch open in the bottom of the two lower hull quarters is done with drill, square files, and sanding sticks. The work goes pretty well if you take your time and outline the inset gratings molded into the plastic with a Sharpie pen. You'll lose all that beautiful detail, but to be a practical r/c model submarine that works as a wet-hull type, it has to be done. I suggest you punch out all the holes before sticking the hull quarters together, the parts are easier to handle when they are smaller assemblies. Note, the lower hull has also taken advantage of the engraved lines of the torpedo tube shutter doors to open those up -- that model will later be outfitted with six practical launchers. Page 8

9 Preparing And Assembling The Sail Once you have marked out the holes that go under the sail, snip the two nubs (indexing pins) off the hull and at their former location, drill 7/64" holes. These will pass the 4-40 machine screws that hold the sail assembly down onto the upper hull. There is a third nub, back near the after portion of exhaust fairing, on the after upper hull quarter. Snip it off too, but drill no hole there yet. Flip the forward upper hull piece and work on the inside. Open a 1 x 1/4 extension of the square hole. (see above) This will eventually pass the pushrod magnet that makes up to the magnet at the base of the sail plane bell-crank assembly. Note the orientation, and the side where you put in the new cut, and it's measurements. Grind away excess. The outboard long side of that the hole butts up against the raised portions of hull under the sail -- those raised portions accommodate the longitudinal indexing troughs atop the hull. The photo shows how the linkage eventually goes in there. With masking tape, put the sail halves together, ready to open up the bottom of the sail to pass the bow plane linkage (mounted within the sail) and snorkel head-valve assembly (mounted atop the hull, but fitting within the installed sail). Two complete sails are shown here. The top sail has already been opened up, the bottom sail has been marked off. Page 9

10 Tack-glue the forward and after resin foundation pieces within one half of the sail, then tape the other half of the sail onto it. With a Sharpie pen mark off the spot where you will drill a 3/32" hole and tap it for a 4-40 machine screw. Take everything apart and punch those holes and cut the threads into the sail foundation pieces. Most apparent in this photo, at the base of the sail, at its perimeter, the plastic extends down into long-running lips that engage the deep troughs set within the top of the hull. The two 4-40 machine screws running up from within the hull into the resin foundations fixed in the sail make fast the sail to the hull, yet provide for quick and easy separation of the two for transportation, adjustment, or repair. When the r/c SKIPJACK leaves the surface, an unobstructed path for venting air, trapped in the diesel exhaust fairing, has to be provided. Failure to get all the air out of the fairing will upset the boats trim and make it difficult to hold exact depth when cruising along at slow speed. So, the following operation has to be done before securing the sail foundation pieces (sail-to-hull mounting foundations-r) to one half of the sail assembly: Grind a 1/8" deep by 1/8" wide vent channel atop the after foundation piece. A corresponding vent hole is drilled into the top, forward bulkhead where the exhaust fairing meets the trailing edge of the sail proper. You will need the ability to flex the bottom of the sail a bit to get the lower sail plane bellcrank (sail plane bell-crank-t) on and off its bell-crank shaft retainers (sail plane bellcrank shaft retainers-s). To accomplish that the sail foundations are glued to only one side of the assembled sail. This permits the unglued underside of the sail to pull away from the other sail half when flexed to install or remove the lower sail plane bell-crank. Page 10

11 You see here how the sail plane operating shafts fit within the rather thick hub of the resin upper bell-crank (sail planes and bell-crank-q). The gear portion of the upper bellcrank engages the gear portion of the lower bell-crank which works around its shaft to rotate the upper bell-crank when subject to the axial motion of the pushrod that runs from the motor-bulkhead of the SD. Here I'm grinding away the raised molded in place bores of the original operating shaft holes projecting from inside the sail halves. The hole, as it is, is too big for the 1/8" diameter sail plane operating shaft. You see between the trailing edge of the sail planes and the ground away bore of one sail half the as of yet untouched bore. A small resin bushing (sail plane operating shaft bushings-n), installed into the original hole reduces its diameter to the required 1/8" bore required by the sail plane operating shaft. The two bushings are pushed in and CA'ed in place. Note that a set screw, set within the hub of the upper bell-crank unit, secures the operating shaft of a sail plane -- these set screws easily reached from the opening in the bottom of the sail assembly. Tape the halve of the sail together. install the sail planes by running each operating shaft into the bore of the upper bell-crank. With the two planes lined up with they're cords parallel to the top of the sail, and the center of the gear section faced down and perpendicular to the cord, tighten the two set-screws to secure the planes to the upper bell-crank part. T h e t w o r e s i n l o w e r b e l l - c r a n k shaft retainers are placed on the ends of the brass pivot pin, and the entire unit installed into the inverted sail and oriented so that its teeth meshed with those of the upper bell-crank. Squeezing the hull halve together between thumb and forefinger, to hold the shaft from moving, tack-glued the retainers to the sail halves -- use only enough CA to hold them in place. Check that rotation of the lower bell-crank caused free unbinding rotation of the upper bell-crank. Break and reposition the retainers as required until free, minimal back-lash operation of the linkage is achieved. Page 11

12 Position the clear piece that represents the emergency stern-light within the sail, then assemble the sail and hold it together with masking tape. Avoiding those areas where masking tape is (you don't' want the thin glue to get sucked into the tapes edges by capillary action) brush thin solvent cement along the seam at the leading edge of the sail, along the top of the sail where the sail top piece will sit, along the trailing edge of the sail, and over the seam atop the diesel exhaust fairing. Also run cement onto these seams from the inside. Leave the assembly to dry for a few hours. DO NOT apply cohesive glue to the bottom of the sail. Remember, you want to flex the bottom portion to get the lower bell-crank shaft in and out of its resin retainers. Page 12

13 Installing the Sub-driver Foundations Before installing the two sets of Sub-driver foundations, shock absorber, and SD Velcro strap foundation, it's wise to mark out a centerline to the inside of the lower hull quarters. Examine the two sets of resin SD foundations provided. The smaller set (C) goes aft and the cut-outs within those clearly defines where they butt up against a frame in the lower after hull quarter. The other, larger set of foundations (E) fits against the forward face of the aftermost frame in the forward lower hull quarter. Note that the circular edge at the top of these foundations is not concentric with the circular edge at the base. On both sets of foundations the narrower portions of the pieces of the foundation halves meet at the bottom of the hull -- get that straight before CA'ing them permanently in place! With the forward set of SD foundations (E) glued against the frame, butt the after end of the Sub-driver shock-absorber (D) (where the pin projects up) up against the forward face of the Sub-driver foundations. Center it, then using a line pencilled, mark onto the hull where the holes will be drilled to pass the six securing 2-56 machine screws. Remove the shock absorber and grind away a 1/2" wide, 3/8" deep channel down between the two halves of the Sub-driver forward foundations. This channel permits disassembly of the shock-absorber components, should that every be necessary. The forward end of the Sub-driver strap foundation (P) butts up against the after face of the forward most frame of the after lower hull quarter. (The tall end of this resin piece goes forward, the shorter end goes aft). Lay the piece on its side within the hull and mark off where you will punch two 3/32" diameter holes into the bottom of the hull, these will pass two 2-56 flat-head machine screws that secure the strap foundation piece to the lower hull. Before drilling a hole, push a pointed rat-tail file hard into the plastic, a sort of 'pilot-hole' that works to guide the drill bit as it opens up the hole. Drill out 3/32" holes to pass the flat-head 2-56 machine screws that secure the SD shock absorber to the bottom of the forward lower hull quarter. To the outboard side of the hull, bevel these holes with a counter-sink bit to accept the flathead screws that secure both the shockabsorber and strap foundation. Page 13

14 Welding the Lower Hull Together The forward and after lower hull quarters are welded together using solvent type cement. As you can see, the two hull quarters are mounted on a flat board to insure that their edges fall along the same plane. Note that a rubber band is used to push the after end of the forward quarter down hard onto the radial flange of the after quarter. Just as in metal welding, which involves pre-heating of the weld area, the contact areas of the plastic to be bonded is treated to make it receptive to deep fusion once the state change is effected to the parts being joined. Before assembly, the radial flange of the lower after quarter and mating surface of the forward lower quarter are soaked in the very thin solvent cement to soften those surfaces. Then, quickly, the gelled solvent cement is beaded onto the flange and the two hull quarters assembled on the flat board, the rubber band made up, and the work left for twelve-hours to harden. Once the center, radial union between the two lower hull quarters has hardened, the assembled lower hull is taken off the board, inverted, and the two upper hull quarters are set upon it -- a test dry-fit. any sprue left at the horizontal centerline between the lower hull and two upper hull quarters is identified, cut and filed back until a tight fit between the three hull pieces is achieved. Take things apart, insert two slivers of wax-paper onto the edge of the lower hull over the radial joint -- this to prevent any adhesive that runs down from the upper hull pieces from getting onto the lower hull piece. Don't worry, if you keep the wax-paper slivers small enough they will conform to the tongue-in-groove union enough to not distort the fit between the three hull pieces too much. Or, you can wax the edges. Your call. Lay the after upper hull quarter down, get it to register with the lower hull and hold the assembly together with rubber bands. Soften the flange of that piece and corresponding inside surface of the forward upper hull quarter with brushed on thin solvent cement, Page 14

15 then smear on beads of gelled cement to the surface of the flange and quickly position the forward upper hull quarter on top of the lower hull and make the assembly fast with rubber bands. Leave the upper hull to dry twelve-hours. As the r/c SKIPJACK features a hull that opens up at its centerline equatorially, it's vital that the upper and lower hull index together as well as possible owing to the fact that the only clamping force applied when they are assembled is at the extreme bow and extreme stern. Any misalignment between the two hull halves during assembly of the quarters would suffer unsightly open seams between the halves. Here, a length of sprue has been heat-stretched to a mean diameter of.025". This is used to fill the inevitable seam between the two hull quarters of the upper and lower hull pieces. As with preheating of metal parts to be joined is done to enhance fusion, wetting the groove between the hull quarters liberally with thin solvent cement works to soften the plastic and weld with the adjoining filler rod and hull quarter. If need be, to insure an open seam of uniform width and depth to better receive the filler rod -- use an eighteentooth-per-inch hack-saw blade to achieve a uniform.025" wide by.025" deep groove for the filler rod. Lay in the filler rod, brushing on solvent as you go. Things get gummy as you work and soon the rod dissolves into the adjoining material. The result is a near perfect fusion weld between the forward and after hull quarters. Carefully following the inked on radial lines, a razor saw was used to remove the tailcone from the after upper hull quarter, and bow from the forward lower hull quarter. Using a wide hard-block, sand the radial faces of all parts with #240 sandpaper. If you were careful you lost no more than 1/16" of kerf, that will be made up later with CAbaking soda filler. Page 15

16 Assembling the Upper Hull Carefully following the inked on radial lines, a razor saw was used to remove the tailcone from the after upper hull quarter, and bow from the forward lower hull quarter. Using a wide hard-block, sand the radial faces of all parts with #240 sandpaper. If you were careful you lost no more than 1/16" of kerf, that will be made up later with CA-baking soda filler. (Right photo) To the right are installed flanges. Center and left are yet to be installed flanges and the hull sections they go into. you want one-half of the tail-cone flange (after radial flange-v) to project past the radial edge. However, you ant only 3/8" of the forward flange (forward radial flange- W) to project past the bow pieces radial edge. As they arrive, the stiff, polystyrene flanges are flat. Put a curl into them by running a flange piece over a small dowel as you apply pressure between dowel and finger as you pull the flange through. Keep at it until the flange retains a curl close to the radius of the part it will fit within. Test fit the flanges to the tail-cone and bow piece. Onto the bow piece flange mark with pen or pencil where some of the flange overlaps two of the flood-drain openings. Once you've affirmed a good fit of the flanges, remove them, cut away those areas of the forward flange so marked, coat the flange and hull pieces with thin solvent cement to soften they're surfaces, apply gelled cement, then quickly assemble the flanges to their respective hull pieces, clamp and let sit for at least twelve-hours. Page 16

17 A single 4-40 flat-head machine screw passes through a hole in the upper hull half, pushing it all down upon the after radial flange. Up forward, the radial flange of the lower hull captures the bow piece attached to the upper hull, pulling the two hull halves together. The Sharpe-kachur Z union at work! Page 17

18 Installing The Sail If I gave the impression in a previous installment of this article that the lower bow piece could be installed to the upper hull half before installation of the torpedo tube nest assembly (the three piece structure comprising nest transverse bulkhead-f, nest keel piece-g, and torpedo muzzle bulkhead-i), I was mistaken. The nest assembly must first be assembled, CA'ed within the forward hull piece, and only then can the forward hull piece be glued to the upper hull half. At this point most of the major assembly chores have been done. All that is left is to screw the three pieces of the torpedo nest assembly together, glue it into the lower hull section (the one sawed off from the lower hull); mount that bow piece under the forward end of the upper hull; make up the securing screws to the Subdriver shock-absorber and strap foundation; and test fit the SAS snorkel assembly (if used). Note here the two round-head 4-40 machine screws that run up from inside the upper hull, through the base of the sail, and into the thread of the sail foundations. This is how the sail is pulled down securely upon the hull. The sail plane pushrod is made up to demonstrate how its magnet engages the magnet partially encapsulated within the resin arm of the lower sail plane bellcrank. The short length of tube extending into the hull projects into and made tight by the elbow's O-ring. The elbow unit in foreground shows off this sealing O-ring. The 90-degree elbow fitting that makes up to the induction tube permits the rather stiff 'flexible' induction hose to make up to the manifold atop the Sub-driver without getting in the way of the sail plane pushrod. The elbow accepts, through its watertight O-ring, the projecting induction tube, the body of the elbow rests up against the top of the hull where it is slathered with RTV adhesive to hold it in place, as you see in the elbow glued within the top of the upper hull. This permits removal of the entire snorkel assembly for maintenance, yet assures watertight integrity of the snorkel assembly when reinstalled. Page 18

19 Before running through the screw fasteners through the bottom of the hull, making up the Sub-driver Shock- Absorber and Strap Foundation, bevel the outside of the holes to counter-sink the flat-head screws. Use a variable speed drill and a sharp bit, and keep the speed slow to insure the plastic does not melt. The sail is removable is afford access to the hull mounted SAS snorkel assembly, as well as to adjust the sail planes if needed. The snorkel assembly comes with the Sub-driver. The reason I had you assemble the two sail halves together, but not the top of the sail, was to permit viewing through the open top of the sail as you check the snorkel float free to run the 1/4" or so vertically without rubbing up against the inside walls of the sail. Once satisfied that all is well within, the sail is taken off the hull, and the top piece glued in place with thin formula solvent cement. The job of the Sub-driver shock-absorber is to dissipate collision energy, acting as a damper. So doing, the shock-absorber enhances the models ability to avoid handling and running damage, such as shearing of the Sub-driver indexing pin or crushing of the models bow. The spring loaded Shock-absorber acts as a d a m p e r A s h o c k - a b s o r b e r i s recommended for all models employing 3.5 sized Sub-driver's and up nuts tightened on the screws, then treated with Threadlocker or CA, keeps them from vibrating loose. Apply CA around the base of the shock-absorber where it meets the hull. Page 19

20 Installing the Torpedo System A torpedo firing SKIPJACK is an optional. The nest foundation is provided with the fittings kit. Torpedo Tube Nest foundation (H), all sit secure and in proper registration atop the keel piece. The muzzle ends of the tubes project into and are held in alignment by the torpedo muzzle bulkhead. and a technical paper on the system, index.php?/knowledgebase/article/view/ 359/47/torpedo-launcher-instructions-172 The Torpedo Nest assembly's primary job is to stiffen the bow of the SKIPJACK against handling and collision damage. It is a vital part of this boat, even if torpedoes aren't installed, and the Torpedo Tube Nest foundation (H) is not installed. The three pieces that make up the nest assembly attached together with the aid of four 2-56 round-head machine screws and CA wicked into all joints.. A quick and easy means to insure that the torpedo muzzle bulkhead and nest transverse bulkhead fit perpendicular to the nest keel piece is to lay the assembly over some graph-paper and eye-ball it. Block sand the forward and aft keel edge to square up the unit. The SKIPJACK kit is principally made of 'high-impact' polystyrene plastic that has nowhere the strength and shock resistance of glass reinforced plastic (GRP). In the picture above a nest of six 1/72 torpedo tubes, secured within the Page 20

21 Note how the bottom edge of the keel piece indexes with the anchor well and frame that projects up from the bottom of the forward hull piece -- it insures that you get the nest assembly to sit the correct distance from the front of the boat. The two engraved lines, one either side of muzzle bulkhead, will help you With the Nest Assembly s radial orientation within the hull. Test fit the Nest Assembly into the lower bow piece and mark off the contact points between within the hull with a pencil or pen. Remove the next assembly and rough up the contact areas with #240 sandpaper. Do the same for the upper hull half, where the torpedo muzzle bulkhead will make contact in that section. Molded into the sides of the torpedo muzzle bulkhead are engraved longitudinal lines to guide you as you register the nest assembly to the lower hull piece. When lining up the assembly rotate it until the two engraved lines fall along the edge within the bow piece, and proper radial alignment is achieved. Pressing the assembly down tight into the lower hull, tack-glue it to the hull with staggered dabs of thin formula CA. Release the pressure, then check again for proper alignment. Apply thick formula CA along all contact points and let it soak in and harden. Leave the CA to cure naturally. If you are going to equip the SKIPJACK with a practical weapon system, before installing the nest assembly, grind and file open the torpedo shutter doors. This picture shows to good advantage how the lower edge of the Nest Keel Piece (G) indexes the nest assembly Page 21

22 lengthwise by engaging the forward frame and raised anchor well. Note that in this shot, the bow portion of the lower hull half has not yet been razor sawed away. the gap and the two pieces start to fuse together. To insure a tight seal, rubberbands are wrapped around the assembly. If you wish to install the SKIPJACK torpedoes see torpedo-systems.html Each weapon system package contains one launcher (which can be configured for either mechanical or pneumatic actuation) and three gas propelled torpedoes/weapons. The Torpedo Tube Nest foundation (H) is optional and is only used if you opt to include the Torpedo Launchers. This can always be added at a later date. The flat heads of the screws holding the Sub-driver shock-absorber (D) and Sub-driver foundation (C&E) on the bottom of the hull need to be secured permanently. A drop of thin CA adhesive is dabbed onto each screw head and left to soak in about a minute, followed by a sprinkling of baking soda to wick up the adhesive and cure it. Work the CAbaking soda filler with a file to conform to the curvature of the hull. Glue the forward lower bow piece to the upper hull half. Note the pencil mark near the inboard and outboard edge of the upper hull -- marked off to indicate where to stop brushing on the thin solvent cement used to soften up both the upper hull matting edge and lower bow section mating edge. Once you get the mating edges softened with solvent adhesive, the two pieces are assembled, more thin solvent cement was run into the seam where capillary action pulled it into Page 22