Vosper-Perkasa News

This is the fifteenth entry in the build log and relates to Step 15: Final Assembly. This step covers the accurate fitting of the forward and aft superstructure along with any methods to retain these items securely. Aditionally an ‘On-Off’ switch plate is fabricated and fitted.

To fit the rear superstructure, the hull requires some minor preparation of the hull opening, this is to remove any nasty sharp edges that may cause injury and to ensure the two lugs on the rear superstructure fit accurately and allow the rear edge of the moulding to fit accurately agains the rear deck. On my example, one of the two plastic lugs had snapped off, so I removed the other and made two new ones from four peices of 3mm or 1/8″ marine ply. These new lugs, along with two more peices of 3mm or 1/8″ marine ply are added to act as guides at the underside of forward end of the rear superstructure. All new lugs and guides are fitted 7mm inboard of the side edges of the underside of the moulding, which now slides fore and aft in the hull opening accurately and easily yet is a firm push fit into the closed position.

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To fit the forward superstructure, the hull requires some additional minor preparation of the hull. I used a 2mm drill bit as a router to carefully open up all the slots in the deck to allow the tabs on the superstructure to fit through. Once these slots were drilled, I used a needle file to true them all up. I also used the needle file on the forward tab of the moulding. At this stage I found it difficult to get all tabs of the moulding into the deck and to stay there. So I added a large wooden beam, profiled to fit the camber of the deck, under the deck at about the door positions. It was glued in with Stabilit Express, see below.

This beam holds the deck, (note the colour change on the RAL 6003 Dark Green / Humbrol Matt 30 using digital photography), at the correct shape and when used in conjunction with a steel hook glued firmly underneath the bridge and some short model aircraft wing retaining elastic bands, the arrangement acts as a very secure retaining system.

Now all I need to do to securely fix the forward superstructure is to follow the 4 steps below:
1 Hook the two rubber bands onto the wire hook.
2 Fit the forwardmost tab into the deck slot.
3 Wrap the two rubber bands around the beam and hook them on to the hook once more.
4 Fit all the remaing tabs into the remaining deck slots, one side at a time works best.

Finally the radio ‘On-Off’ switch plate is made from two more peices 3mm or 1/8″ marine ply, one part to hold the switch, the other to act as a stand off from the underside of the deck in order to allow the rear superstructure to freely slide back and forth over the switch. See image below.

This is the fourteenth entry in the build log and relates to Step 14: Deck Fittings Assembly 2. 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 that I fitted dowels of 2mm diameter brass to two of the four corners of each torpedo launcher, (along with correspondingly placed 2mm holes drilled accurately in the deck), allowing a very positive part location and fixing. The remainder of the small items such as parts C17 are also fitted with brass dowels to aid secure fixing to the deck.

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Photos above and below show (apart from my lack of interest in ironing) the practically completed model (with the hull primed and wet flatted), however all fittings are at this time just placed on the model. This is because I need to handle the hull some more for the fixing of the front superstructure retaining beam (see step 15) and I must install and test the radio control installation before fixing many fragile items to the deck. Experience has taught me that no matter how simple a step appears to be, it usually ends up becoming more complex. So I have for a long time now adopted the philosophy of getting the model to operate correctly far before completion. This prevents potential damage in any fault finding that may be required later on.

This is the thirteenth entry in the build log and relates to Step 13: Deck Fittings Assembly 1. The instruction manual appears to have steps 13 and 14 in reverse, as step 13 shows the placement of items assembled in step 14. Consequently, I shall describe the assembly of the fittings in this step and the placement in step 14. This step is very straightforward, however, I did deviate from the instructions in four areas:

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

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The picture below shows a close up view of the tripedal torpedo launch levers and jackstaff parts made from scrap brass rod and tubing. These are formed using long nose pliers or similar until they fit together accurately when assembled into the drilled deck holes. I used a micro butane torch to solder these as it takes so few seconds to melt the flux and allow solder to flow. Heat is then removed and after a short wait (until the solder dulls) the item is then held in long nose pliers and removed from the deck. Make 4 tripods and 1 jack staff.

The tube sleeves are not cut to any specific length, they are just cut with the brass part flush with the edge of the K & S tube cutter. I.e. When you place the tube in the tube cutter, just push the tube through until it is flush with the other side of the cutter.

This is the twelth entry in the build log and relates to Step 12: Guard Rail Assembly. The kit offers two options here, the injection moulded plastic stantions, or the photo etch brass stantions. The latter being made totally flat.

I opted for a third option, turned brass stantions. The items I used are (3 packs of 10 in each pack) Graupner 25mm 2 Bar Stantion - Part Number 450.3. The Graupner items are drilled for a 0.8mm hole, but I drilled these to 1.25mm becuase I know for a fact that I would not be able to thread the stantions with such small holes.

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20 stantions are used as is (drilled only in my case) whilst 6 more are made into ‘A’ frames. Construction of the ‘A’ frames is undertaken by first drilling the stantion holes to 1.25mm as mentioned above, then a flat is filed onto the top ball at right angles to the existing holes. I then threaded the 1.25mm drill through the lower hole to enable me to hold the stantion at the correct angle whilst drilling. Firstly I used a 0.5mm drill turning very slowly initially, in order to obtain a correct centre, then at slightly higher speed to drill through. Finally the same hole is drilled to 1.25mm also. 1.5mm brass wire cut to appropriate lengths are then held in the Dremel chuck and rotated whilst being filed to make a reduced diameter to fit the ends into the new 1.25mm stantion hole.

The extra legs are then formed using long nose pliers or similar until they fit together accurately when assembled into the drilled deck holes. I used a micro butane torch to solder these as it takes so few seconds to melt the flux and allow solder to flow. Heat is then removed and the item is then held in long nose pliers (so that both parts are held securely) and then removed from the deck. At this point I examined the ‘A’ frames and, if necessary, applied more flux, heat and solder. Once finally cooled, I re-drill the top cross hole first at 0.5mm then at 1.25mm. Make 6.

The only other items I used that are not standard in the kit were brass eylets. These I think are billing items (from an old Nordkap build) and two will be glued into the fore decks to act as railing hooks, another 2 will be formed into hooks allowing the railing wires to be finished nicely. Naturally at this stage these items are just loosely fitted to the boat and as you can see, some appear at slightly drunkard angles.

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.