Scratch Build Soviet Project 667 BDRM Delta IV SSBN K-18 "Karelia" Scale 1/140

[Davidh]

Hello all, Quiet week..

I have been flat out with a couple of orders lately and haven't had much time to develop the 667 further. However have managed to get the missile deck mostly completed. The top and sides of the level deck up front have been done and so now mainly called for the sloping rear deck to be completed. I marked out on the rear hull section where the sloping deck meets and transitions into the rear hull. Where the missile deck meets the rear hull will be a slightly raised flat deck section. This allows the narrowed deck as it slopes to level yet keep a walkway path that is generally about the same width until it gets closer to the very stern where is gradually evolves into oblivion. The top rear section sits just behind the main flat section and glues into a recess. The two side pieces are triangular but feature a slight cut away where the raised hull section transitions to the main diameter before the end of the missile deck. I also had to Champfer the underside edges of the rear vertical pieces because they meet the curved hull section at such an angle that they thickness of these pieces would mean they would stick out. I took a plane and trimmed off material at quite a steep angle.








Along with angling the lower edges to conform to the radius of the hull I also ground out a curves section on the underside of the rear end of the structure to accommodate the fact that the flat rear deck needs to meet a curved hull section that will curve down either side of the deck. This is simply to make sure that the deck is as low as possible when it transitions. Once the top section was carefully glued in place with the right angle to transition to flat. I cut out and glued in a triangular web section to reinforce the top piece and make sure it stays at the exact angle I need it to. From here I could glue the sides on.








Once the missile deck had all its surfaces, it would be a case of sanding and making sure all the surfaces were flush with each other. I would also take the sliding bevel set to the right angles to make sure that the surfaces were at the corrects angles sloping inwards on either side. On old sailing ships this outward angling surface I believe was known as the "Tumblehome". After running the sliding bevel along it became pretty clear that it was consistent along the length of the missile deck, even at the transition where it slopes down and inwards towards the stern.

The front section of the missile deck received small pieces of plywood that were glued in from the front of the sides and met at the front in the highly tapered front section. I spent some time sanding underneath as like the stern section it would be transitioning with the curvature of the hull. The lower section her where the deck meets the hull can actually be left a bit rough as there will be some substantial filleting with filler as the transition between hull and deck vertical surface becomes obvious. This won't happen until I am happy with the missile deck before I screw it down to the top of the hull with the self tappers.






Enough for now..


David H

[Davidh]

Thanks Brady.


Yes, I particularly like the 667 because it kind of has a sleek inelegant clunky-ness to it. There is always plenty of character in these designs with their over sized missile decks and control surfaces that just don't look adequate enough to do the job..

Talking of missile decks. I have started building it and putting the pieces together. As I am making the missile deck as a unit that is stand alone I can make it and check every angle before bolting or in this case screwing it down to the PVC pipe. I highly recommend doing as much as you can in a modular way. It allows the freedom to check everything first before sticking it all together. I think that If I build the missile deck piece by piece onto the PVC I would'nt find it as easy to check all dimensions and get that dreaded elusive symmetry that we all crave....

As can be seen by the last photos I have glued the plywood side pieces onto the profile pieces at either end and used tape to keep the tension whilst gluing. I could have used G-clamps but having a slight angle they would gradually ride off the assembly. I took the time to check the alignment of all the pieces.

As I was working on the creation of the Missile deck I also turned my attention to the fact that the 667 has raised hull section that at its lower end creates a typical missile deck groove that is so often found on the lower edge of missile boats. I assume it facilitates drainage under the missile deck section. In order to create this raised hull section which wraps either side , parallel with the missile deck and running just beneath it and up over the top of the hull I needed to cut and sand back to size a rectangular piece of PVC pipe that will be glued to the top of the PVC hull effectively increasing its diameter in an unbalanced way by about 3mm. Looking at the drawings you could see that the thickness of the PVC pipe was just ideal to match the thickness of the widened hull section. Yay!







You can see in these photos the raised PVC rectangular pipe section that forms the widened hull section that wraps around the top of the hull amid ships







Yep, I realized I should have used a piece of PVC pipe NOT left over from a building renovation. I have had to scrape away paint around the areas that I work. The raised hull sections will be pasted over with filler in order to create the gradual transition needed where this surface then lowers back into the over all hull diameter. I don't need to apply filler over the top however as this is where raised deck section will fit over the top. The lower edge of the missile deck will fillet very gradually into this raised section just above the groove.

667 had a date with the alignment board. It would come sooner or later. If you are scratch building a boat you simply can't do without it. This is the board where you have your model suspended between two centres as though you are going to turn it up on a lathe. It allows you to get your alignment right and work out your symmetry. Yep, that thing that subtly makes or breaks so many jobs. I bought a 90 mm pvc end cap that I could slip onto the edge of the pvc hull pipe. I drilled a hole dead centre and popped it on where the stern section will go. I then drilled a hole in the middle of the bow round section and places it on the spindle at either end.

























Once the sides were glued down and checked over with the sliding bevel I started work on the top section. This top piece needed holes in it to correspond with the holes above the backbone structure underneath in order to get the self tapping screws into the backbone and through the PVC pipe to finally secure the missile deck when I am happy with it. This top piece was glued on the top and given time to glue. PVA glue can be slow. Over the top of this piece would eventually be glued the Renshape strip that would take all the detail of the missile deck. This would be one of the last things added and only after the deck was screwed in place. However there will be lots of times that the Renshape will be fixed down to the top of the deck whilst I check alignment, the start of the radius as the deck slopes around the sides and finally checking the transition between Renshape and plywood for scribing the detail of the sides of the missile hatch doors as they go around that radius.






Anyway, enough for now. As always any ideas tips and insights, welcome.

David H

[DMTNT]

Those fences add a certain, Russian "clunkiness" to it all. Elegant in their function, even if it's not the the cleanest looking design. Kind of like a Kalashnikov...

It's fantastic. Great work David!

-Brady

[Davidh]

Hello all,

Back to work and dripping in this heat and humidity. Still I suppose its better then freezing in the northern Hemisphere.

I have actually spent a fair amount of time working on the Appendages. Once printed out to the right size I then will give it a coat or two of Spray putty and then go over the imperfections with some filler. Sand back and then re-spray. I have so far probably spent more time working with the horizontal stern planes than any other component. This has also come after realizing that there are different drawings out there that actually have subtle differences in the depiction of the stern planes. So I took the designs that most resembled the photos I was looking at of the 667's rear end and went with that. The Blender design for the stern planes featured the vertical end plates. Unfortunately the printer's interpretation of the geometry left me with plates that broke off really easily. So I decided to get rid of the stern planes as they were printed and would create the needed items out of 1mm thick styrene sheet.




The inner fence is wider than the outer one. The edge of the end plates remains a constant relative to the surface of the plane. There is a radius at either end and the one at the leading edge is bigger than the trailing edge. I used two arcs to create the outer most panel, made a copy and then used this to size the inner panel which would be bigger. I then carefully sanded these down so that they would be identical and would fit along the chord of the surfaces. I had to sand back the outer profile of the planes to accomodate the thickness of the two panels. Once these were right I could then glue the panels onto the respective ends. I had to sand the outer surface slightly inwards as the outer surface actually angles back ever so slightly.

I have had to take a very fine file and file off some sections around the front of the plates. I also have has to remove a small amount of material along the trailing edge where the plate will move up and down and would jam up against the plane surface, essentially creating two small grooves top and bottom in front of every panel to allow it to move into the rear of the plane and allow a pivoting movement.

You can also see that I have had to make a scale concession by creating a housing for the rod at it comes to the end of the plane. This is to some extend hidden by the panel.








I made a start on the Missile deck. This is what makes the Delta series so distinctive. This big hump-back gives the 667 that not sleek look. It is an imposing structure and will probable make the boat look like its still on the surface when it's nearly at Periscope depth.. The missile deck would be primarily made out of plywood sheet that would be fixed to sectional profiles. One up at the front end just behind where the Sail will be and the other will be just where the break in angle occurs and the deck then declines down to meet the hull. I measured the overall dimensions needed for these pieces. Two top pieces and four side pieces. These would be supported by a frame underneath and the whole unit would be screwed down on the top of the PVC pipe with long self tapping screws. The top of the Deck will feature a 5mm thick strip of renshape that will take all the detail onf the missile desk and missile doors. The good thing about the 667 BDRM is that there are noticeably less drainage slots on the side of the missile deck.




The missile deck will be built in such a way that I can work on it off the hull until I finally screw it down to the hull to transition it into the hull. To make the missile deck strong enough for me to work on I created a central structure for the screws to go in and give it the rigidity needed to make sure that there would be more warping whilst working on it stand alone... This frame consisted of a base piece with end pieces and fillet pieces. Holes drilled to align up with those in the top of the hull aligning with the center line running along the top of the hull. I spent a bit of time making sure that the end profiles are identical and that the crucial angles are the same. The sides must be at exactly the right angle to each other.


David H

[Davidh]

Thanks Jorg, David and Brady,

I thought as much being a spanwise flow issue. Reduction of tip vortexing.

So I have got to the point where I can give a very rough assembly of most of the main hull parts to get an overall appreciation for the shape and size of this bad boy. I had marked out and drilled the holes for the positioning of the main shaft of the horizontal planes. Once the holes were drilled and light could be seen through one end, it would be possible to get a brass rod and slide it through with one end assembly in place. Once passing it through to the other end fitting the other horizontal plane assembly on. At this point I needed to dremel out a section just in front of the holes. This would be where the extending section that protrudes out the root end of the horizontal fixed plane, that acts as a securing point but is also acts as a section of sprue during the casting method. Without grinding out this section the stern section will not sit flush up against the hull. It does'nt so much matter at the moment because eventually this whole area will be covered over with the filler profile that will be where these planes intersect with the rear hull.





As can be seen in the first photograph the root edge of the planes needs to wide towards the rear of the side of the hull. this is because of the taper on the hull. This will be accommodated in the fillets that will be narrow at the leading edge and wider at the trailing edge. As can be seen I have been going through an ongoing process of eyeballing the length of the rear end, drawing the concentric lines around the hull to see detect any further undulations that may have crept in. I have needed to address them now for as soon as the fillets for both horizontal and vertical fillets are in place being able to sand over a wide area easily will not be as easy therefore making a smooth transition across an overall surface more difficult. After I was happy with the latest installment of smoothing and 'symmetricalling' I then gave the whole back end , especially the areas that have been heavily sanded back a coat of resin. This after drying allowed me to sand back and get a really smooth surface that would allow for even finer analysis. Re-establish the ;lines over the rear end and do the process all over again...

I have also created and used a series of templates to match the angles of the booms , both on the inside and out to check that they are symmetrical..






Here is an image i pulled off one of the Russian websites showing a plastic kit stern end of the 667. This kit looks abit rough however proportion wise I think it actually checks out...
















Next write up will be about the end plates on the horizontal planes.

David H

[He Who Shall Not Be Named]

That’s interesting. I was having a conversation with my dad (who is a pilot) not too long ago, and we got to talking about how aerodynamics & hydrodynamics are similar in so many ways, but then not at all in others given the difference in density and properties of water vs. air.

The significant variance between the two fluids is the compressibility of a gas (air) and incompressibility of a liquid (water). A propeller in water can cavitate. A propeller in air can go super-sonic. Two situations that affect propeller performance. But, by and large, the two fluids are fair analogs -- that's why you sometimes see a submarine model in a wind-tunnel. Reynolds Number will correct for geometry and viscosity.

David

[DMTNT]

They serve like wing-fences or vortex-tips on an aircraft. On the submarine, the function of these appendages is to prevent water from sneaking up and around the ends of the planes from one face to the other when deflected to the water flow. Control surface deflection to the water flow produces a differential pressure between the two faces of the control surface -- its that differential which produces the force (lift, if you will) that pitches/yaws the submarine about its c.g.

David

That’s interesting. I was having a conversation with my dad (who is a pilot) not too long ago, and we got to talking about how aerodynamics & hydrodynamics are similar in so many ways, but then not at all in others given the difference in density and properties of water vs. air.

[He Who Shall Not Be Named]

Maybe those plates on the planes prevent the towed array from beeing stuck in between. Or they protect the rudders for under-ice ops. Typhoon has those, too (but lacks a towed sonar...)

They serve like wing-fences or vortex-tips on an aircraft. On the submarine, the function of these appendages is to prevent water from sneaking up and around the ends of the planes from one face to the other when deflected to the water flow. Control surface deflection to the water flow produces a differential pressure between the two faces of the control surface -- its that differential which produces the force (lift, if you will) that pitches/yaws the submarine about its c.g.

David

[JHapprich]

Maybe those plates on the planes prevent the towed array from beeing stuck in between. Or they protect the rudders for under-ice ops. Typhoon has those, too (but lacks a towed sonar...)

[Davidh]

Hello all,

As pointed out by Jorg one side in particular was not as straight down the side as it could have been. I have once again taken to the filler and a ruler and dragged the edge of the ruler over the radius of the side and made the filler smooth over the subtle parts that created the undulation that was causing offence. I have also taken with a file to the radius on the inside of the booms to just get them even.

I have actually spent a fair amount of time going over the symmetry of the twin booms. If I don't get this right there will be problems. I have also sanded back further area where there are inconsistencies around hull frames as seen from the stern looking forward. Once this was done I needed to check alignment for the back end. I have been thinking for some time about how to get a twin boom to rotate and to secure the wedge shaped middle in between the booms in such as way as to make it secure without damaging the rear end. I simple decided that with what I needed to do I would not at the moment need to rotate the stern section. So I decided to have it rest on the base and create a two pin connection with nails going into the twin booms and the forward section sitting level on the base. I just needed to work out my equators and vertical axis line. This would allow me to make a start on the horizontal stern planes.







The 667's stern planes are quite small in comparison to the rest of the boat. They also feature these vertical fence like panels. They remind me of the wing fences on the MiG 15-21. At first when I printed these out they were so brittle and weak that they simply broke of when pulling the surface off the printer platform. If they did survive the removal process then they were bent or not of constant thickness so I simply decided to do away with them and I'll create styrene ones later that will be more hardy and consistent thickness. I will them need to think about how to arrange them the best way for the silicon mould making process a couple of months down the track. I have also taken a liberty off scale by adding a very small round hinge section as I cannot see how the rotating shaft is secured towards the tops of the stern planes. It's all covered over and hidden mainly behind the vertical plates.






I would also have to make sure that the outer panel /fence would be angled in slightly towards the trailing edge. Can anyone give me the details on whys some Russian boats have these vertical plates on the stern planes? Both vertical and horizontal. I would be really interested to know.
So moving on the alignment. I made a small block of particle boat and accurately measured and drilled two holes along a horizontal line to mark and secure the twin booms. The height of the line above the base needed to be exactly the right height so the rest of the hull would sit dead level. At this point they have been drilled out and have a 4mm thread in them that I have used to screws the propeller on to check for accuracy and how the boat is going to look. (I frequently put everything together just to get a feel of its overall looks and proportions. This make me feel like I'm getting somewhere! ) Once this was done the stern section could be fitted on and should have the equator lines be exactly the same height off either side of the board. This would allow me to then scribe an accurate horizontal line along the length and help me work out the placement of the stern planes. This would allow me to accurately measure the distance to the trailing edges and leading edge of the fillet profile. It would also allow me to accurately mark upwards abive the equator to establish the centreline for the stern planes since on Russian boats this is above the overall centreline. (something I was only aware of towards the very end of the Papa build, thanks Jorg and HWSNBN!)

Once this was done I could mark out the exact spot that would be the location of the stern rotating shafts and drill a hole for them. This is always tricky as it means drilling holes from either side and making sure they line up. Sure it can be a dogs breakfast inside the hull however you do not want to come out anywhere other than the opposite hole you have just created. Tricky also because my drill bits are not long enough to go all the was through.


















As you can see the parts are quite rough, however they will slowly get polished. It's all about getting the alignment right and everything square.
Once again any comments or recommendations would be great.

Off to bed. Try and get to sleep in this humidity. It's still 28 degrees!..

David H

[Davidh]

Thanks Brady,

Thanks for the comments, I’m pretty happy with how she’s looking so far...

As an Industrial arts high school teacher I have been doing a lot of 3D printing. I get to take the school ones home to practice and ‘get to know the technology’.

As for hiding the layers I use an automotive spray putty.

https://www.ritepricedistributors.com.au/products/aasp400-septone-spray-putty-aerosol-400g?utm_medium=cpc&utm_source=googlepla&variant=37585983686&gclid=Cj0KCQiAvebhBRD5ARIsAIQUmnm2z8PaDcqr9E7Unf0i5qckY6h-52OEf7JV77RPygk_3zgiipQwuiEaAkDpEALw_wcB

you should be able to find a US equivalent. Spray on sand back ,spray on sand back, spray on......... finer and finer set and dry after about six-seven coats it looks really good.

David H

[DMTNT]

I have always had a soft spot for the Delta IV and am watching this progress with great interest.

You definitely know your way around 3D printing, and it looks like you are putting it to fantastic use. I am curious how you deal with the stirations on the surface. I have always had mixed results getting the surface of 3D printed material to look smooth like polystyrene or resin.

-Brady

[Davidh]

Thanks Jorg, Scott T .

will have a good look at stern and address those issues...

Dave.

[Scott T]

Maybe you could shine a laser level light on it to check symmetry.
Would be nice to have a machine like this to rough out the shape.

[JHapprich]

Hey david, this is what i noticed
Regards, Jörg