Vosper-Perkasa News

This is the eleventh entry in the build log and relates to Step 11: Rear hull Assembly. Give yourself plenty of time on this step as it involves the alignment of the motors and shafts. Time spent here will pay dividends in terms of battery life and model performance. Step 11 covers installation of (1) Transom Fittings: Jet Efflux Deflector, Jet Exhausts, Flag Staff & Trim Tab. As well as (2) Running Fittings: Hull Preparation, CNC Parts, Rudder Tubes, Shaft Brackets, Stern Tubes, Rudders & Propeller shafts.

(1) Transom Fittings: This stage (image of completed step shown below) is divided into 4 sub stages:

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a) Jet Efflux Deflector: After adding Tamiya Putty to correct the shape of the curved jet efflux deflector, the key is to correct the angle of the mating face so that it sits flat on the transom so that the two arms each side run parallel to the rubbing strake. The alignment is from the very top edge of the efflux deflector to the very bottom edge of the circular jet exhausts. The two grooves in the hull are in the wrong place and need to be opened up to suit the correct position. I used an old soldering iron to do this.

I drilled the back of the deflector with a 2mm drill and fitted 2mm brass wire dowels to this part for security. Corresponding holes were drilled into the transom. The efflux deflector was glued in place with Stabilit Express and sealed around the joint face with more cyano, then when dry the edge was sanded and filled with Tamiya Putty. See the following photo for reference.

b) Jet Exhausts: These holes were opened out with a router bit and then shaped with a Dremel sanding drum until the large disks fitted securely.

Now, these caps are just that, caps, for engines running these caps will be open and placed on the top of the efflux deflector. So the correct placement is to fit the thin caps to the efflux deflector and fit the thick caps from the inside in reverse so as to represent the inside of the open turbine exhaust.

c) Flag Staff: This was made from some 2mm brass wire with a tube sleeve at the base to allow it to fit into another piece of brass tube, acting as a socket, fitted into the transom at the correct angle. The brass tube socket was glued with Stabilit Express on the inside along with the ends of the locating dowels also.

d) Trim Tab: In its current form the trim tab will not be strong enough, so I cut back the forward edge until the square beam on the leading edge of the trim tab was in contact with the transom, thus ensuring a much stronger gluing area. The tabs were left in place, but similarly shortened. The trim tab support / control rods, were made from more 2mm brass wire with a brass tube sleeve at each end to act as re-enforcement. The trim tab holes were drilled right through and corresponding holes were drilled in the efflux deflector to accept the other ends.

Stabilit Express was applied to the holes in the efflux deflector and the brass wires fitted through the trim tab, then through the two sleeves, then into the efflux deflector. More Stabilit Express was used to secure the trim tab end of the wire and to position and secure the brass sleeves. Ensure the trim tab remains square and flat whilst drying. The resulting construction is incredibly strong.

(2) Running Fittings: This stage (image of completed step shown below) is divided into 6 sub stages:

Note: www.Vosper-Perkasa.com is the only supplier (worldwide) of the deluxe version of this kit, which includes a cnc cut boat stand, cnc cut internal parts and of course the obligatory 3rd propshaft, stern tube and coupling.

Note: Optional, outstandingly beautiful, scale cast brass propellers (click here for more information) are fitted to this build as well as brass rudders - these are not standard kit items.

a) Hull Preparation: Re-enforce the hull deck joint on each side of the hull from just rear of the forward torpedo launcher base to about 6 inches /150 mm from the bow. Use Stabilit Express to perform this action and allow to dry. Once dry, it is possible to shape the rubbing strake, either by scraping with a blade or by using of a file. Use of Stabilit Express on the previous step will reduce the risk of breaking through the rubbing strake in thin areas. Once or twice I did break through and used Tamiya putty to fill any minor holes. Tamiya putty softens the ABS hull so use masking tape above and below to ensure it goes only where it is supposed to go. Drill holes in the hull for the rudder tubes.

At this stage I sprayed the entire lower surface of the hull with high build filler primer (I used U-Pol High #5), applying several coats around the stern tube and trim tab area, taking care not to get any on the face of the transom. Once dried I used a hard sanding sponge and soapy water to ‘block flat’ the entire hull. This takes a little time, but is more than worth the effort. The resulting hull looks as smooth and flat as a GRP hull. I also took a coarse square needle file to the underside of the bow to correct the rubbing strake moulding.

b) CNC Parts: Assemble the ends and sides of the cnc frame with cyano.

Fit but do not glue the motor mount cross member (as per the illustrations in the build notes). Do not fit or glue the two cnc deck parts.

c) Rudder Tubes: Tack glue the rudder tubes into the rear end of the cnc frame. Fit the cnc frame inside the hull to mock up the assembly, push fit the rudder tubes in position in the rudder holes and align the opposite (bow) end of the cnc frame into the V of the hull, this is so that you can see the extents of the gluing areas.

Mark around the edge of the cnc frame on the inside of the hull with a marker pen or scribe, then remove the cnc frame and key the interior with 60 or 80 grit paper to ensure the Stabilit Express holds the cnc and other parts in place. Do not glue yet.

d) Shaft Brackets: The shaft brackets must be assembled with Stabilit Express or similar to ensure maximum possible strength.

Use a 2mm drill as a router bit to open up the three slots in the hull for the shaft brackets. Do not glue to hull yet.

e) Stern Tubes: Refit the cnc frame with tack glued rudder tubes into the inside of the hull. Tack glue the frame into position with small applications of cyano only. Place weights on the frame to hold it into the V of the hull and allow to dry. Once dry, carefully remove the motor mount cross member and fit the three electric motors with couplings using the M3 bolts, spring washers and washers provided. Refit this assembly into the cnc frame. Turn the hull over and drill the 6mm holes in the stern tube outlets. Fit the shaft brackets to the shafts and fit shafts to the couplings on each motor. Rotate the shafts by hand to check for ‘run-out’ and if necessary re-move and refit the shafts in a different position on the coupling. The shafts must exit the hull without touching the hull anywhere. All three shafts and shaft brackets must be parallel with each other and in alignment. Now Key the finish on all three stern tubes with 60 or 80 grit paper to ensure the Stabilit Express (applied later) holds.

Open up the stern tube exits as shown in the photograph to ensure that you can fit a stern tube on the shaft without changing the alignment in any way. Do this for all three slots and when satisfied, apply masking tape to the outside of the hull over the stern tubes to hold them in position and to cover any gaps that may exist. Tack glue from the inside, then re-check. Once the tack glue has dried, use Stabilit Express to cover the stern tubes and the shaft brackets from the inside as shown in the photograph.

The rule of thumb here is the bigger the (keyed) gluing area, the stronger the glued joint. Allow to dry thoroughly. Leave everything in position overnight, even though Stabilit Express sets in about 20 minutes, it generates heat and can possibly continue fully setting for several hours. Once hardened, remove the shafts from the couplings. Finally apply Stabilit Express to the sides of the cnc frame for final gluing. Also add Stabilit Express to the rudder posts where they exit the hull and where they are tacked into the cnc frame. Temporarily fit the cnc servo deck to the rear of the frame to securely hold the rudder tubes in position whilst the adhesive sets.

f) Rudders & Propeller shafts: These are a bolt on, bolt off fit, so leave them on for now until you need to remove them for painting the hull and rudders. At this time, I removed all removable parts from the hull and gave it 3 or 4 coats of grey primer, followed by wet flatting with 800 grit wet or dry used with warm soapy water. This results in smoothing the primer to an almost gloss finish.

This is the tenth entry in the build log and relates to Step 10: Engine Room Housing Assembly. This step is very straightforward, as its just the fitting of the fittings made in the previous step.

Note: Brass wire and tubing used in this build are not standard kit items.

The only tip I would give here is for the fitting of the part A42 (a small box) to each side of the engine room and the life ring. So as to make gluing and positioning this small box easier, I placed cellotape over the side of the engine room housing, then over taped it with soft masking tape and marked on it the dimensions of the box in pencil. I basically aligned it with the edge of part C48 and made it one box height higher. Once marked, I cut out the square with a scalpel and removed the masking tape and the cellotape square, leaving a pristine square of plastic for gluing the part accurately and neatly.

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The same marking technique is used for the life rings, but this is fitted with spigots into 1.5mm holes drilled into the engine room housing. This way the part can be painted and then fitted and glued from inside the moulding without risk of glue spillage etc. The remainder of the parts are straightforward, but I have not glued any more items together yet as the base will be a different colour to the structure and the fittings.

Finally, I drilled 0.5mm holes in the hatches to accept brass wire for the hatch handles. These handles were fitted at random angles, but close to the correct angle, for realism. Cyano was used for all assemblies. Painting (spraying) will commence when most of the assemblies are completed.

This is the ninth entry in the build log and relates to Step 9: Engine Room Fittings Assembly. This step is also straightforward.

Note: Brass wire and tubing used in this build are not standard kit items.

There are only a few rudimentary fittings to assemble for the engine room housing. Although I did once more decide to replace the plastic upright on the exhaust mast, the rest of the parts are just glued, filed and filled as necessary.

For the mast, I carefully cut off the upper mouldings and drilled them out to suit some 2mm brass rod with a Dremel. The plastic parts are then slid onto the brass rod and cyano-ed in position. The top of the exhaust outlets are then drilled to accept the brass wire and also are drilled underneath to accept another cut down stantion soldered to the forestay rods (again from brass wire).

Finally a small eyelet was cyano-ed in position on the streamlined forward part of the exhaust outlet to enable quick rigging and de-rigging of the model’s aerials. Cyano was used for all assemblies. Painting (spraying) will commence when most of the assemblies are completed.

This is the eighth entry in the build log and relates to Step 8: Forward Superstructure Assembly. This step is quite involving or straightforward, depending upon how much you are going to diverge from the instruction. I decided at this stage that I would scratch build a brass mast to replace the plastic item in the kit. Additionally I decided to make the handrails out of brass wire also, using brass stantion rails from the scrap box, drilled out to suit the wire, then cut in half to create (two per stantion) ball shaped fixings to which the handrails are soldered.

Note: Brass wire and tubing used in this build are not standard kit items.

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In order to solder these handrails accurately, they must be assembled on the wire and fitted to the drilled holes in the superstructure. The golden rule, apart from using a decent flux, is to let your soldering iron heat up fully, for at least 10 to 15 minutes before use. Whilst this sounds counter-intuitive it is born from the fact that the hotter the iron, the lower amount of time you will need to make a neat soldered joint. It takes just a few seconds to tin and create a great joint with a very hot soldering iron. If your iron is not hot enough, you may end up overheating the railing and causing the plastic to melt on the superstructure. If you have any doubts about your soldering abilities, just cyano the pins to the brass railing, then when set, as would be the case when fully soldered also, carefully remove the railings from the model and clean up with a file etc as required.

As you can probably tell, I enjoy soldering, so I scratch built a new mast from brass wire, tube and rod. I also added very small eyelets to allow quick rigging and de-rigging of the model’s aerials. the mast is also soldered to a stiff brass rod, whilst a suitably fitting brass tube is fitted as a socket in the superstructure roof to accept it. I freely admit, even as the importer of this kit, that I would prefer the kit to have a brass parts pack to enable everyone to make a far stronger mast than the plastic one. However, the total spend on extra items for this kit, would only be about £30 so far, in 2 new metal rudders, 40 brass stations and three or four one foot lengths of brass wire, rod and tube from the ‘K&S Metals’ rack at the local model shop.

The photo shows the completed assembly with brass items fitted for the photograph. Yet to be fitted is the rotation servo, see below for the conversion notes, the LED navigation lamps and the signal lamp.

Also, I chose to convert a Futaba S3003 Servo (these are much cheaper than small motor gearbox combinations and you know the rotation speed) into a small motorised free running gearbox. Now there are two methods that one can take to do this, one gives you the ability to switch the servo on and off from the transmitter, (still enabling the potentiometer for feedback on R/C control) the other simply makes the servo rotate from the moment the receiver power is applied. It is the latter three step method that I choose to perform on the servo as a switchable radar was deemed un-necessary. In each of the following photos, the image on the left is the ‘before’, the image on the right is the ‘after’.

Step 1: The main conversion was to un-wire the servo lead from its current position on the servo printed circuit board PCB (now the warranty will be void), then re-solder the positive and negative wires (noting the red positive polarity dot on the motor) directly to the motor. I elected to break the tracks where the motor is soldered into the PCB to avoid current leaking back into the electronics. Shown below.

Step 2: Remove the servo gears and cut the travel limiting lug from the output gear. Shown below.

Step 3: Physically push down the feedback potentiometer to bend the metal supporting rods, so that it no longer engages under the output gear. I.e. the output gear rotates freely without turning the potentiometer. Shown below.

Re-assemble, plug into a spare receiver channel socket and power up. The output disc on the servo will rotate at a lovely scale RPM for a radar.

Click play to start the video.

This is the seventh entry in the build log and relates to Step 7: Bridge Console Cover Assembly. This step is extremely straightforward.

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There are only 5 plastic components for this assembly. All that is required of the builder is to true up all the parts with a file so they fit together properly and fill in some more sink marks. The photo shows the completed assembly in position in the flying bridge. Note the triangle gussets fitted underneath the over hang.

Liquid poly is used for all plastic parts. Painting (spraying) will commence when most of the assemblies are completed.

This is the sixth entry in the build log and relates to Step 6: Wheelhouse Internal Assembly. This step is includes a mix of PE, injection moulded plastic and cnc cut styrene. Even so, its straightforward. Begin by removing all the injection moulded parts from the sprues, true up and fill as necessary. For the cnc cut parts, I recommend first using some abrasive paper on both sides of the cnc parts sheet before removing any parts, this will save you much time later on. When you have keyed both sides, remove parts as required.

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Assembly of cnc styrene parts is made substantially simpler by sellotaping sections together at the correct angles first, then when held securely, apply cyano inside or where necessary to make a secure joint. Even though cyano takes minutes to dry, allow at least half an hour, then remove the sellotape and clean up any glue residue on the joints etc. Refer to the build notes to make certain you have the orientation of the parts before gluing. Finally, when all styrene parts are assembled, glue the injection moulded parts and the PE wheel as required. The photo shows the completed assembly.

Where glued, cyano is used throughout. Painting (spraying) will commence when most of the assemblies are completed.

This is the fifth entry in the build log and relates to Step 5: Bridge Console Assembly. This step is very straightforward, although I have replaced one of the plastic parts of the assembly with some brass wire for durability.

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There are only 4 plastic components for this assembly and one brass rod (to mount the ship’s wheel). All that is required of the builder is to true up all the parts with a file so they fit together properly and fill in some more sink marks. The photo shows the completed assembly in position in the flying bridge.

Liquid poly is used for all plastic parts, however, cyano is used for the brass wire. Painting (spraying) will commence when most of the assemblies are completed.

This is the fourth entry in the build log and relates to Step 4: Radar Assembly. This step is quite straightforward, although I have replaced some of the plastic parts of the assembly with either brass wire of brass tube. This is for two reasons: 1) To make a far more robust unit, and; 2) to enable motorisation (when the receiver power is switched on).

Note: Brass wire and tubing used in this build are not standard kit items.

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Assembly of the radar structure is very basic work, and my departure from the instructions results in only slightly more work. Three parts requiring drilling with a 2.5mm drill and a 0.8mm drill to accept the brass parts. Finally the superstructure roof is drilled to accept the radar tower feet and the brass tube for the radar shaft. Leave the brass tube about 75mm long so that it can be cut down to size when the motorisation unit (a modified spare servo) is fitted later. The assembled tower is shown below.

The radar and shaft are built as follows. Drill the underside of the radar antenna with a 1mm drill then use a 2.5mm drill to accept the diameter of the brass tube used. Solder a short 3mm length of brass tube onto the radar shaft. This increases the gluing area of the brass into the radar antenna. Finally key, then glue the brass shaft into the base of the antenna. All that remains to be done is the fitting of the modified servo and the pulley / gears system. I will describe in this blog at a later stage how the servo conversion is done.

Cyano is used throughout to glue the assembly together. The final photo shows the completed, but as yet unpainted assembly with the radar antenna fitted. Painting (spraying) will commence when most of the assemblies are completed.

This is the third entry in the build log and relates to Step 3: Torpedo and Launcher Assembly. This step is quite time consuming and its best to take an evening for each launcher and a final evening to make the torpedoes them selves. Construction takes two different routes, one being photo etch only and the other being standard plastic kit construction.

Construction of the Photo Etch Launchers.
Begin by removing all necessary photo etch parts from the sheets, using a scalpel or similar, enough to make one launcher. File off any remaining tabs from each part. For the next stage, I consider it essential to purchase some Tamiya Photo Etch pliers, (see photo) these will make the bending of the PE parts much easier and far more accurate. It is not possible to bend the lower edges of the launchers in one go, so do one side at a time.

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To increase clamping force, hold the arms of the Tamiya pliers firmly (but carefully) shut with a pair of regular pliers. This will stop the PE pliers from opening as you make the bends. Take your time and make sure with the sides that you make handed pairs and not two sets of left hand side etc. If you do, just get another two PE side parts and make two sets of right sides to compensate. The sides are the only handed parts of the PE assembly so make sure you get this right on the first one, before being tempted to make all 8 side parts in a production line style. Once formed, all parts must be glued together, use a needle file or similar to key the surface and to remove some of the PE resist lacquer.

Note: You will not be able to solder these items because of the lacquer, it is very hard to remove even when using a strong flux.

Use sellotape or similar to assemble the sides together at the correct 90 degree angle before attempting to glue. Use cyano throughout and allow to dry thoroughly before filling off any unsightly excess glue marks. The assembly gains significant strength as it is being built but be careful with the thinner item. The final addition to these parts (not shown) is to fit two brass rods (one under each corner) to act as location spigots when fitting these launchers to the deck.

Construction of the Plastic Torpedoes.

Begin as discussed in the previous build log pages, by removing all the necessary items from the sprues and clean off the flash with either a scalpel or nail file / needle file. Fill any sink marks or ejector pins marks with a plastic model putty. Once dry the remainder of the excess putty can be filed off as necessary.

Assembly of the torpedoes is very basic work, but do take your time to file and later fill all the joints. The propeller rings (part C25m) are fixed with a 2mm plastic spigot into the rear of the torpedoes, so I have not yet glued these as I will temporarily mount all four torpedoes on 2mm brass wires on a wooden block in order to hold them for spray painting. As you can see, I fitted the warheads and filled the gaps, I will spray paint the warhead colour later, this I believe will result in a far better finish than painting the warhead separately and then gluing it on the torpedo, as test fitting will show that it simply will not fit well enough without a little work to true the parts up.

Where glued, liquid poly cement (brush applied) is used throughout. The photos show the completed, but as yet unpainted assemblies. Painting (spraying) will commence when most of the assemblies are completed.

This is the second next entry in the build log and relates to Step 2: 20mm Twin Oerlikon AA Gun Assembly. Begin as before by removing all the necessary items from the sprues and clean off the flash with either a scalpel or nail file / needle file. Fill any sink marks or ejector pins marks with a plastic model putty. Once dry the remainder of the excess putty can be filed off as necessary.

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The photo etch ring requires care when removing it from the sheet, use a scalpel or similar to break through the joining tabs. File the breaks clean with a file and use a pair of long nose pliers to bend the parts accurately and carefully to shape. Use a 0.8mm drill and pin chuck to drill through the foot plate in the 3 marked locations to fit the PE part. Once fitted, push the PE through about 2mm and reverse bend the PE to secure the feet. Apply cyano to fix.

At this stage the twin gun barrel and pivot assembly are not glued (and will be secured with piano wire axles after painting) nor is the plinth. However the steel tube shaft has been glued to the assembly with a firm push fit into the plinth. Where glued, cyano is used throughout. The photos show the completed, but as yet unpainted assembly. Painting (spraying) will commence when most of the assemblies are completed.