Assembling the Thor 1/96 SEAWOLF kit

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  • He Who Shall Not Be Named
    Moderator
    • Aug 2008
    • 12256

    Assembling the Thor 1/96 SEAWOLF kit

    I've long had a glass reinforced plastic/fiberglass (GRP), resin and white-metal Precision Pattern (http://www.precisionpattern.biz/subs/index.htm) 1/96 SEAWOLF kit. Ten years ago I only got as far as hull half alignment and basic clean-up work on the appendages, sail and hull. I'm starting this WIP article with the GRP hull and sail done to the point of primer, and the Sub-driver (SD) installed. Jobs remaining include appendage attachment, control surface linkage integration, installation of the snorkel mechanism, fixed ballast and buoyant foam (this is a wet-hull type r/c submarine), and creation of a new rotor.

    I've taken on the project again with intent to finish it in time for the 1/96 fleet run this October in North Carolina -- I want this guy to join my fleet of other 1/96 scale r/c submarines there.

    I'm no stranger to this particular product: previously I assembled and made RTR two of these kits for customers. So, this one ... MINE!! .... is a cake-walk.

    The Precision Pattern 1/96 SEAWOLF kit features the usual exceptionally high standard of glass layup on the hull parts, and bubble free resin pieces this outfit is known for. However, the rotor for the pump-jet (PJ) is awful -- way to short of pitch, so I'll solder together a replacement from cartridge-brass sheet blades and a turned machine-brass hub.

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    Some eye-candy for you -- shots of a RTR SEAWOLF assembled for a client. Just to give you an idea of the end-game of the article presented here. As to the performance of those commissioned models, using the kit supplied rotor: Slow; turned like molasses; and wobbly as to stern plane response; very good response to bow plane commands. Surfaced and submerged performance was, in a word, awful! The 1/96 sized model SEAWOLF's revealed themselves to be piglets in the water.

    However, I anticipate that a new, higher pitch rotor -- driven by a 28-turn, five-pole 555 sized motor geared 3:1 -- will produce the thrust, and hence the speed, needed to give the stern planes and rudders more bite underway ... we'll see.

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    Cheat marks and lines molded into the hull denoted where to install the rudder shafts, horizontal stabilizers and anhedral stabilizers (the anhedral stabilizers work to counter the inboard roll resulting from submerged high speed turns). These identifying marks were a big help, but could not guide me as I worked to install these appendages perpendicular to the hulls longitudinal axis. So I made a hull mounted, disc-shaped appendage alignment fixture -- used to guide me as I lined up an appendage and CA'ed it in place.

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    The appendage alignment fixture was temporarily secured to the after end of the hull by small machine screws passing through elongated holes within the brass straps that made up to the indexing fixture. This permitted adjustment of the fixture till its plane was perpendicular to the hulls longitudinal axis. The horizontal reference (datum) plane being a true work-table and the vertical plane established with a 90-degree tri-angle.

    [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image020.jpg[/IMG]


    Who is John Galt?
  • He Who Shall Not Be Named
    Moderator
    • Aug 2008
    • 12256

    #2

    [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image002.jpg[/IMG]



    I used medium-thick CA adhesive to glue the horizontal and anhedral stabilizers to the hull. No need for pins or other re-enforcements as the wide footprint of these parts at their roots was wide enough to ward off breakage against anything but a drop to the shop floor. I'll sum it up. CA is an excellent bonding agent in this situation for two reasons:

    1. the glue is strong, sets quickly, and will wick into the smallest of gaps where it will harden into a grout and bonding agent.

    2. when hit with a high pH solid (backing soda) or liquid (an Amine or other high pH liquid accelerator that won't attack the substrate), the CA will immediately change state to a solid.

    This permits use of CA and accelerator to achieve fillets and other gap filling structures That not only are workable, but strong enough to lend considerable tension and shear strength to the union. Worked with files you can achieve gap-free, strong unions between parts in only minutes -- not hours!

    Each appendages was tack-glued in place, using the alignment fixture as a guide -- insuring each appendage projected off the hull at a right angle from the hulls longitudinal axis.

    Invariably there was a gap between hull and the attached appendages. Into the gaps I forced baking soda, a high pH grout. Onto the surface of the grout I poured thin-formula CA which immediately saturated the grout and flashed the filler into a solid; while at the same time enhancing, considerably, the bond between appendage and hull.

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    Specialized rasps and 2nd-cut riffler files made quick work of the baking soda-CA fills where appendages met hull. Complicating the filing chore was the tight space between horizontal stabilizer and anhedral stabilizer -- this necessitated the use of custom made rifflers specifically shaped to work this particular job.

    The large array of files seen is the usual set-up when I sit down to perform a difficult material removal task. Not all the tools seen in this photo were used. However, each was tested by making a few passes over the work. Those files not meeting the criteria of ease of handling and blade conformance to the works surface were rejected. This done till I had a round and square section riffler file that suited the job.

    If a suitable tool were not found in my rather massive collection of files, I would have formed a new, dedicated-to-the-task file for the job.
    As described next:

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    Turning cheap straight file blades into riffler file blades is both economical and permits you the ability to make a tool that precisely fits a specific filing task.

    Introducing bends into the stock straight bladed Jeweler's files high-carbon steel is easy: You first bring the portion of the blade you will bend to a red heat; then, with the aid of pliers, bend the file blade to the desired shape. A quick quenching in water hardens the metal back to working stiffness.

    Oven mitts recommended!

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    The CA-grout smeared unions were worked with an array of diamond, square, and flat Jeweler's riffler files. This operation left the inevitable file marks on the hull and appendages. These were filled with an air-dry touch-up putty.

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    Nitro-Stan is the putty of choice. A medium stiff flat brush was used to drive the putty into the file marks. If applied in a thin coat like this the putty will dry hard enough for wet-sanding in about fifteen-minutes. Sometimes it's useful to cut the putty with a high-quality lacquer thinner, but that was not required on this job.
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    The deep scratching (file marks) on and around the unions between appendages and hull were filled with air-dry Nitro-Stan. Do to the relatively deep scratching in some areas I applied two coats of filler. That obligated me to wait twelve-hours before wet sanding it all down with #400 grit sanding sticks.

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    Old Flexi-File sanding tools (chosen because of their stiff but flexible nature) had fresh wet-and-dry #400 sandpaper glued to their faces. These reconstituted sanding tools were then cut on the band saw to be wide enough to be useful, but narrow enough to get into the tight spaces between stabilizers. All sanding was done wet with plenty of water used to wash away the grit so I could see progress as I cut down the putty to the primer gray of the model parts, leaving only that putty needed to fill the file marks.

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    The pump-jet on this model kit -- with the exception of the white-metal (tin-antimony) rotor -- is made up of two rather complicated resin pieces: The after half of the PJ duct with post swirl stator blades within, and streamlining bullet; and the forward half of PJ duct with the pre-swirl stator blades and stern cone section that mates with the hull.

    Given the high thrust this propulsor generates, it's vital that the units thrust line run as close to parallel to the hulls longitudinal centerline as possible. In pursuit of that objective I ran a length of 3/32" diameter brass rod through the forward PJ resin piece. A disc-shaped centering fixture was cut from 3/32" thick Sintra (PVC sheet) and tack-glued within the after portion of hull -- a 3/32" hole in its center accepted the forward end of the brass rod, forcing the resin PJ piece to align its stern tube bore with that of the hulls longitudinal centerline.
    Who is John Galt?

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    • He Who Shall Not Be Named
      Moderator
      • Aug 2008
      • 12256

      #3
      [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image002.jpg[/IMG]



      The PJ piece in place on the hull, a wrap of Electrician's tape to keep the bonding epoxy resin from running down the outside of the hull. Here I'm ready to introduce the epoxy to fill the internal gap between PJ parts flange and inside of the hull.

      [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image004.jpg[/IMG]



      The radial flange of the PJ part was not tappered. So, when pushed into thehull there is, at its top, a large annular space between flange and inside of the hull. All I had to do was align the PJ piece to the hull; sit the hull on its tail; pour in some catalyzed epoxy laminating resin; and let gravity do its work. Next day, I had a permanently bonded PJ piece to the ass-end of the SEAWOLF hull.
      Who is John Galt?

      Comment

      • He Who Shall Not Be Named
        Moderator
        • Aug 2008
        • 12256

        #4

        I depart from the 1/96 SEAWOLF kit assembly briefly to address an often overlooked but vital item every r/c model boat/ship/submarine operator should employ: a proper storage-transportation box.

        I think it safe to say that at least fifty-percent of the damage a model water-craft suffers is encountered during storage, transportation, and 'handling' -- most of these events occurring well away from the lake or pool. Would it not make abundant sense to employ every reasonable effort to protect your fragile model from bumps, drops, and inquisitive child hands? Your model is vulnerable to damage during that trip from the home display stand to the water's edge. You should do something about that.



        Just some of the boxed models in storage in the house, awaiting for their turn in the water. Each transportation-storage box designed for a specific r/c model submarine.

        I note that many r/c model ship drivers who contribute to this site have many model ships in their respective fleets -- how many of these models are (right now!) resting on rafters or hanging off of wall mounted brackets, all awaiting the evil doings of the family cat or local earth tremor (sorry, California).

        A box, to my way of thinking, is a vital element of the entire kit-assembly/model building project. If you don't provide your r/c model a proper box, then you've not completed the project.



        Empty completed boxes, less the internal foam padding that will eventually girdle a completed model. Orphans. The models they are for are in the shop, uncompleted. These boxes serve as bucket-list reminders every time I visit the shed.

        They ... haunt me!



        It's not enough to bang a simple box together from 1/4" exterior-grade plywood sheet; 3/4" square molding; a bunch of finishing nails; glue; deck screws; and some varnish. No. You also have to install a close fitting foam foundation that not only restrains the model against all degrees of motion, but also cradles the model in such a way as to not abrade the models finish or damage delicate parts.



        The main structural element of a model transportation-storage box is 1/4" thick plywood. Strive for the cheap stuff, which is usually 'exterior' grade. But be on the lookout for sales. Here, I've scored some interior-grade plywood they were dumping at the local Lowe's.

        You can pay a lumber-yard big bucks to strip a sheet of plywood to your specifications. Or, you can buy one of those cheapie battery powered man-eating sharks (AKA, Harbor Freight circular-saw), and with the aid of a 48" long steel-rule, rip your own sides, tops, and ends. Cut carefully and all you'll need to dress the edges up is a sanding block.



        The two side, two end, and single bottom pieces of plywood are held together with glue and finishing nails through 3/4" square molding. The square sectioned pieces give rigidity to and provide plenty of bonding area to the assembly. The flange faces, at the open top of the box, become the seat upon which the removable top is secured with deck screws.

        Note the large holes in the side pieces of plywood. Often the model is put away still wet, and you want plenty of circulation in there so things don't start growing in there.



        An assembled transportation-storage box, ready for staining and weatherproofing with many coats of Minwax, Polyurethane varnish. Note how the upper 3/4" squares atop the open box form the seating flange for the box top.



        Just like a ship resting upon strategically placed keel-blocks in dry dock -- the docking plan defining the structural hard-points of the ships bottom that will distribute the load of the un-buoyed ship without damage -- the foam foundation pieces within the storage-transportation box distributes the stresses (both gravity and other acceleration forces) acting on the model while in transit or being handled between home and van, van to lake, and back. Transport is the evolution where the unprotected model is most likely to get clobbered.

        For the surface ship modeler, the shape and location of the foam transverse foundation pieces is derived from you plans -- the sections. Or, if your plan does not indicate sections: use the waterlines and buttock lines to derive sections for each specific station (frame) you want a transverse foam foundation. Typical transverse foam foundation spacing is 4-5-inches. I use 1/2" thick closed-cell polystyrene insulation foam for the foundation elements. The foam foundation is secured to the inside of the box and box lid with a good quality Carpenter's glue.
        Models of a simple body-of-revolution, such as the SEAWOLF model presented in this article, are a snap: just a series of circular cut-outs in the foam transverse pieces.



        A technique most kit-assemblers and scratch builders know (and if not, WHY NOT!!) is the use of carbon-paper to identify high/low spots on two surfaces that are supposed to have a very tight non-interference fit, such as between the model hull and transportation-storage box foam foundation elements.

        No matter how careful you were lofting off the model, or reading the plan, the system of foundation elements you glue into the box and box top will assemble into an un-perfect fit to the model. To identify the high spots within the foundation, you place a piece of carbon paper -- used with old type-writers (you'll find this rare stuff on e-bay) -- carbon side down onto a portion of the foundation. Then place the model within the foundation, sandwiching the carbon paper between model and foundation.

        The above photo, if you examine it carefully, shows off the dark smears on some of the transverse foam foundation pieces which have picked up the black carbon -- these dark areas denoting material that has to be sanded away.



        To transfer the carbon black to the foundation elements you simply grasp the edges of the carbon paper along with the model and ever so slightly rotate and move the model back-and-forth. The contact (high spots) points between model and foundation will pick up the carbon, identifying the material you need to sand off. The carbon paper sheet is long enough to permit marking of two transverse foundation pieces at a time. This work goes quickly and one sheet is more than enough for the entire foundation, top and bottom
        .
        If you can't find carbon paper you can make a transfer marking aid by simply grinding gray or black charcoal onto a piece of 8.5" X 11" paper (or crayon if you have kids) and follow the steps above. Two cycles of marking-sanding is enough to get a nice, tight fit between hull and foundation. Easy-Peasy.

        Note that all of this work is done while the model is still in primer gray -- you don't want to do this nasty stuff on a painted and weathered model as you put it at risk of picking up glue, carbon, and handling oils. Sins committed to a bare, primed hull are easier to fix than a finished model.



        Though not so easily achieved on model ships with their very delicate topside works, making a securing foundation for the upper half of the rounded submarine model is an easy repeat of the lower half of the foundation.

        The model is secure from motion within the box about all axis. There's a good reason I build my transportation-stowage boxes this way:

        About twenty-five years ago my 1/96 AKULA, secured in its box pretty much like how I've illustrated here, rolled out of the improperly secured van tail-gate as I rounded a curve at 25 MPH. What a sight that was in the rear-view mirror: the box spinning and pawl-vaulting end-over-end as I slammed on the breaks!

        The box was scuffed up, and some of the plies had abraded away or were flapping in the wind. However, the model was intact with only minor damage to things knocked loose within the hull. I've been a believer in transportation-stowage boxes for my models ever since!

        How about you?...







        Who is John Galt?

        Comment

        • He Who Shall Not Be Named
          Moderator
          • Aug 2008
          • 12256

          #5



          Oversized holes were drilled into the top (lid) of the box to pass the securing deck type wood screws. The top was then held in place with tape and the holes used to mark off onto the box flanges where to drill pilot-holes for the screws. The top removed and 1/8" pilot holes drilled through the flanges. The thread of the deck screws were smeared with bar soap and run in and out of the holes to establish the thread, and the top laid in place and screwed down. Typical screw spacing is twelve-inches.



          The end-game, of course, is a transportation-storage box that protects the completed model from handling and transportation damage, yet is engineered not to harm the model in the process. No, this is not the SEAWOLF, it's a completed 1/72 THREASHER.
          Who is John Galt?

          Comment

          • He Who Shall Not Be Named
            Moderator
            • Aug 2008
            • 12256

            #6

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            The kit provided pump-jet rotor (propeller in some circles), on the right, was of poor design: a very low pitch, and way too thick of blade section. Pitch is a linear measurement; the distance the rotor travels axially in one revolution in a non-slip medium (think, Jell-O). Typical marine propellers have a pitch very close in value to the propellers diameter. The kits propeller was not even close -- it would obviously thrash around in the duct without moving much water axially. So, I fabricated a new, proper rotor for the 1/96 SEAWOLF. That unit, on the left. Note the pitch difference between the two. Coupled to a 555 size motor with five poles, and of low turns, the new rotor will produce A LOT of thrust.

            [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image006.jpg[/IMG]



            The kit rotor and my rotor have a diameter of 2.25 - inches. The kit rotor has a nominal pitch of 1.5-inches. My rotors pitch is 2.25-inches. (Pitch was measured, as is accepted practice, at the blades seventy-percent point along the span of the blade).

            I know my rotor is of constant pitch. Don't know about the kits wheel as I did not bother to plot enough radius points along the span of a blade to figure it. Waste of time, anyway: the kit rotor blade thickness is way, way too much ... damned thing would have more utility at the business end of a kitchen blender than in the pump-jet of this model kit!

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            All hand-crafted constant pitch propellers (my rotor is an example) start with a simple blade-radius-angle chart. You plot there the pitch you want, as a vertical line. At the base of that line, at a right-angle to it, the base line is where radius points along the span of the propeller blade are marked off, each radius points distance from the pitch line is the circumference of the circle described at that radius point. A line connecting each radius point to the top of the pitch point denotes the actual angle of the blade at that specific radius point. Note how the blade angle diminishes uniformly from the hub to the tip. This helical twist is the hallmark of a constant pitch type propeller/rotor.

            (But , not always, and that's another story ...).

            I lofted those angles onto a Renshape blank and cut it to shape. And, wa-la! I had the correct helical twist in physical form: a pattern block.

            An annealed brass sheet blade blank laid atop the pattern block -- and forced to conform to the shape of the blade pattern block -- would adopt the required helical twist.
            The pattern block was set aside as I set about the task of machining the brass hub of the new rotor.

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            A piece of machine-brass (a special brass alloy, doped with a bit of lead to make it chip easily when machined --beware! K&S brass is not machine brass!) round-stock was chucked up in a rotary table (a dividing head would be a better indexing tool here, but I'm a cheap *******). The rotary table was then secured to a home-grown tilt-table to position it at the correct angle on the X-Y bed to mill slots whose angle to the axis of the work equated to the pitch where the blades intersect the hub.

            Positioned, chucked down tight, the milling machine was then used to cut in the slits that would later accept the base of each rotor blade. Rotating the work fifty-one-and-change degrees gave me the equal spacing for the required seven-blades of this pump-jet rotor.

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            Who is John Galt?

            Comment

            • He Who Shall Not Be Named
              Moderator
              • Aug 2008
              • 12256

              #7
              [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image002.jpg[/IMG]



              The slotted hub blank was shifted to the lath were I first punched a 3/16" diameter bore to later accept the running gears propeller/rotor shaft.

              Taking one of the rotor blade blanks, I played with the cut of its root till the blade fit a hub slot with the blade presenting the desired sweep and rake. Removed, that blade was used as a template to mark out the other blades, but not cut as I needed the extra material to serve as a handle as I went through the annealing and twisting chores for each. Only after getting each blade to the proper twist on the pattern block was the extra material cut away.

              Taig makes this neat little tapper cutting attachment to the X-Y tool holder -- you make it up, angle it appropriately, and it will cleanly and consistently cut to the same tapper angle. I used this tool to tapper the hub, the angle continuing the SEAWOLF's hull tapper at the stern.

              The hub was then parted from the round-stock and set aside for latter blade assembly.

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              I annealed the blade blanks by taking each to a red heat and leaving them to cool at room temperature. The now soft and malleable metal blade blanks were individually placed on the Renshape blade pattern block and pressed to shape with fingers alone -- the metal was that malleable! At this point a blade was way too soft to be useful. So, each blade, on the pattern block, was peened all over its surface with light strokes of the hammer until the brass had resumed its as-bought hardness.

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              The rotor assembly jig was a straight-forward affair: a piece of shelving for the base; a central 3/16" diameter stainless steel pin to suspend the brass hub; a blade leading-edge crutch (a short length of 1.5" diameter copper tube); and seven 6-32 brass all-thread studs used to compress each blade up tight against the hub.

              The height of the hub (sandwiched between two wheel-collars) was set so that with a blade secured in its slot, and its leading edge making contact with the crutch, the rake of the blade would be correct. Once that height relationship was found through trial and error with one blade --and the wheel-collars tightened -- assembly of the remaining blades went quickly.

              The projecting 6-32 brass studs push the blades up tight into the hub slots. Fine tuning of rake angle was done simply by turning a stud -- a slot in its upper face receiving the blade of a screw-driver. Things were tweaked till all blade tips had the same height off the base of the assembly jig.

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              A solid brass hub like this is one hell of a heat-sink. That means ... unless you have resistive soldering equipment ... you're compelled to heat and solder the entire assembly in one heat-cycle. And, that's just what I did. First, liquid flux was brushed over all union points. The hub was heated with a torch, and once up to operating temperature, solder was flowed into the slots at the top of the rotor and capillary action did its work of drawing the solder into all gaps, producing a nice tight fillet along the hub-blade interface points. Once up to temperature the work took thirty-seconds!

              [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image016.jpg[/IMG]



              Care was taken during the heating to keep the flame off the flammable jig base. Note the water saturated paper towel I crammed into the leading-edge crutch . This kept the pin and crutch cool during the entire operation.

              The soldering job completed, the upper securing wheel-collar was removed and the rotor removed from the pin and the jig retired for later service.

              A lot of work with round-file and flexible sanding sticks went into getting all the fillets at the root of the blades to the same radius. After that initial finishing work the rotor was dumped into some lacquer thinner and the work scrubbed with an abrasive pad. All this to remove the clinging solder flux residue and carbon-black.

              [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image018.jpg[/IMG]



              Any copper bearing alloy simply hates to let things stick to it unless it is well oxidized and presents a surface with plenty of tooth to it. So, to prepare the brass rotor for CA adhesive, putty, and primer work I poured some Ferric chloride acid into a bucket and used it to 'pickle' the rotor before each application of the CA, putty or primer. After the acid, the work is dipped into a bucket of water doped with some baking soda -- the high pH of the wash effectively killing the acid. And the work dried thoroughly .

              [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image020.jpg[/IMG]

              Who is John Galt?

              Comment

              • He Who Shall Not Be Named
                Moderator
                • Aug 2008
                • 12256

                #8
                I purposefully sized the blades so the tips of the rotor would slightly exceed the inside diameter o f the pump-jet duct. This, of course, meant I had to later trim the tips to fit the duct. The initial slop was built in to prevent an inadvertent large gap between blade tips and pump-jet duct -- the tighter the non-interference fit between rotor and duct, the more efficient the propulsor.

                This simple blade-tip grinding tool was put together using the disc-sander. A 3/16" hole was drilled into the plate, distanced from the face of the disc to put the tip of a rotor blade into contact with it. The spinning disc removed a small amount of material from each blade as the rotor was slowly turned. After the initial trimming the rotor was installed into the PJ and checked for clearance. That first test revealed slight blade-duct contact. So, I went back to the machine, moved the plate into the disc a mille-whisker, and repeated the blade tip grinding operation and tested again.

                [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image002.jpg[/IMG]



                [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image004.jpg[/IMG]


                It took three grinding-fit test cycles, but I finally got the rotor to spin freely with about a 1/32" clearance between tips and duct.

                [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image006.jpg[/IMG]



                An unfortunate artifact of all the bending and work-hardening was a dishing of the blades -- good in that the suction side (facing forward) should have a positive camber, but bad in that the pressure side (facing aft) of the blades had a pronounced under camber where the surface of the foil should be flat.

                After the first pickling -- giving the blades surface plenty of tooth to enhance adhesion of the CA -- I applied thick formula CA to the face of the blades pressure sides and left it to cure under a heat-lamp. I then used diamond files to restore the flat to the blades.

                Each time an abrasion operation is performed which digs down to shiny metal you must again pickle the work to restore tooth to the just-abraded portion of the work.

                [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image008.jpg[/IMG]



                After the first pickling, the first shot of prime was applied to the rotor. This revealed a few flaws that either needed to be knocked down with files or filled with air-dry touch-up putty. I use Nitro-Stan 2001 putty -- this lacquer cut putty is applied with a small, flat, stiff brush ... which does a much better job of getting the putty into the blade-hub corners than my fat fingers can't. On occasion I will dip the brush into fresh lacquer thinner and knead that into a small pile of the putty, reducing the body of the putty a bit, making it suitable for application , 'paint like', to large surfaces.

                [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image010.jpg[/IMG]



                Once the putty dries, the work is addressed with a sanding stick and twists of sandpaper, all worked wet. Note that I use a little brass collar (belled at one end) to hold a twisted piece of sandpaper tight while it's being employed on the work -- the twists useful at the blade-hub fillets. The flexi-file was used on the faces of the blades.

                [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image012.jpg[/IMG]



                (Never throw out a flexi-file!!!! Once you wear down the original abrasive, simply glue on a strip of new sandpaper and you're off to the races again).

                The work all sanded down some rotor metal was revealed, necessitation another pickling cycle. Once dry the work was again primed and examined. The prim-putty-sanding-pickling cycle repeated till the rotor finish was near perfect.

                [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image014.jpg[/IMG]



                [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image016.jpg[/IMG]



                [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image018.jpg[/IMG]



                [IMG]file:///C:/Users/David/AppData/Local/Temp/msohtmlclip1/01/clip_image020.jpg[/IMG]



                The completed pump-jet rotor and how it integrates with the pump-jet assembly.

                OK, the grunt-work on this kit is about done, time to integrate the Sub-driver, get things working, trim out the model, and take the primer-gray SEAWOLF to the local diver training pool and check it out.
                Who is John Galt?

                Comment

                • Peter W
                  Captain
                  • May 2011
                  • 509

                  #9
                  I love this article Mr M. Those underwater shots are pornographic..

                  Peter

                  Comment

                  • greenman407
                    Admiral
                    • Feb 2009
                    • 7530

                    #10
                    YOU are the Man Dave.....there is No doubt. Beautiful workmanship!
                    IT TAKES GREAT INTELLIGENCE TO FAKE SUCH STUPIDITY!

                    Comment

                    • Slats
                      Vice Admiral
                      • Aug 2008
                      • 1776

                      #11
                      Nice work Dave. I think the paint job on the prop kills the underlying effort. Shame all that gorgeous effort and work covered up. I agree with Peter strong workshop pornography. Now check your mail.
                      John Slater

                      Sydney Australia

                      You would not steal a wallet so don't steal people's livelihood.
                      Think of that before your buy "cheap" pirated goods or download others work protected by copyright. Theft is theft.



                      sigpic

                      Comment

                      • He Who Shall Not Be Named
                        Moderator
                        • Aug 2008
                        • 12256

                        #12
                        Originally posted by Slats
                        Nice work Dave. I think the paint job on the prop kills the underlying effort. Shame all that gorgeous effort and work covered up. I agree with Peter strong workshop pornography. Now check your mail.

                        Will do. Here's some video of the first sea-trial. An ugly affair!

                        This is the first open-water test of a Thor 1/96 SEAWOLF r/c model submarine. I've built and sold two others previous to this one. I don't paint an r/c subma...


                        M
                        Who is John Galt?

                        Comment

                        • HardRock
                          Vice Admiral
                          • Mar 2013
                          • 1609

                          #13
                          I just read this over again. If I live to be 400 I'll never have these skills (although I do build a good box!). Its a privelidge to be able to access this stuff. What an inspiration.

                          Comment

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