USS Pogy in 1/72

[Slats]

For almost five years I have been scouring the internet for a 1/72 scale unbuilt Sturgeon, then along came the promise of a great kit (and it will be) from Brian Starkes but that too is not yet across the finishing line.

A while back I had thought of getting my own boat together, Anyway the product of that thought and the acquisition of some great plans by Greg Sharpe led me to kick the process off by commissioning a build of a sail and sail planes by a modeller here in Australia. This shown below (photo to be inserted).









Work, and other target commitments shelved the idea of doing my own hull, and then Joel Stadnick and Andy (Subculture) suggested I consider another option......
It just so happens that Joel's long hulled Jack (Permit) hull, is identically geometrically to the the 637 class, (that is the original Sturgeon - not the longer series). With that in mind and a study of the longer Permit hull cf the Sturgeon, it turns out that around half the detail are in the same position on both boats.

Some of the similar detail


For the express purposes of building a Sturgeon in 1/72 scale, I ordered Joel's USS Jack hull, and the rear dive planes, rudders, scopes, and various other hardware and set about a conversion.

Soon after it arrived I cleaned up all the parts of their various mold release material and commenced work with Z cutting the hull, installing indexing lips, and getting a great fit between upper and lower hull surfaces using the supplied screws and installing the securing nuts.

The next job was to fill in a 10mm discrepancy in the stern cone using a automotive filler. The hull despite having identical geometry is designed around Joel's unique Jack counter-rotating bearing, this bearing is of course absent in my case and the hull needed to be tapered off correctly. To do so required roughing up the hull surfaces upper and lower and I did so using my Dremel. Shown below is the work in progress.

Next job was to consider the geometry of the rear rudders - these are a perfect match on both boats (Sturgeon and Permit).

The rear dive planes turn out to be slightly different. As can be shown below there is small discrepancy on the outer aft edges - this is easily fixed by adding roughing up the edge and applying GRP filler.

The largest discrepancy of Permit parts cf Sturgeon is the horizontal stabilisers ahead of the dive planes. What is shown on the photo below is that around a 10mm portion of material is missing behind the Permit's parts cf the Sturgeon. Roughing up the rear edge of this stabilser and tacking some flat styrene in place on either side of a Permit stabiliser with CA, I poured into this section some GRP filler. Then removing the styrene border a perfect match is made.

Difference in size:





Of course as strong as this modified part is, it needs to be stronger, so with the complete permission of Joel, I will be molding this part so that I have two identically strong port and starboard side stabilisers.

The final bit of commence work I did was make a horizontal fin for the rear Stabilisers. This work was done utilising light styrene, which will be molded.






J

[Slats]

Z cut, indexing lips in, and securing nuts in place



Here you can see the Permit rudders match the Sturgeon's


As does the propeller

[Slats]

Lot more work done, in fact basic construction is now complete.

Moulded parts complete for back end


Rear planes, stabilisers, and rudders installed - needs a clean up


Sail and Sail planes installed


She's well on the way




J

[He Who Shall Not Be Named]

Wow! Where did this come from? Wonderful conversion project.

[Slats]

Wow! Where did this come from? Wonderful conversion project.

Thanks - long way to go yet.
J

[redboat219]

Are you posting photos already? I don't see any.

[Slats]

Yes the post has photos, I can see them?

[Outrider]

Make sure you're logged in. I've noticed that photos often don't display unless you're logged in. I've seen this behavior from a variety of sources including iOS devices and several Macs.

[redboat219]

Oh. I thought I was going blind there. I'm currently using an iPhone to view this.

[Slats]

Hi guys,
its been awhile.

I had a great Subregatta and then a short holiday (vacation) in sunny Fiji (Mike, David and Ellie need a holiday), and came back to what in Australia has been a vicious and necessary (non violent) battle for the future of democracy...what can I say I hate the fact that Australia is ruled by an unelected once card carrying (and probably still is) commie who wants to tax the **** out hardworking people. What's being taxed?.. C02. It will cost billions and achieve nothing considering Australian's produce 0.000001% of CO2 in the atmosphere, but will all be winding back our way of life to that just a tad greater than the stone age. The idiot lead scientist here in Australia predicted in 2007 that rains would never fill dams in Queensland - where in 2010 they had the worst floods in Australian history. This idiot advised the Govt in 2007 to build a desalination plant - which after $3bn of work has now been mothballed. Of course the desal plant needed a coal fire powered power station to run it, which is the root of all evil, according to the same idiot - who now has been promoted to Australia's Chief Climate scientist!!! WTF! - Ok enough with the rant suffice to say its a pleasure to be back in here but I it has been a long absence.

This thread is going to be a bit of time machine, as Pogy is long finished and was a hit at the Subregatta we had out here in June.

When we last left the story the boat was together, and the next job was painting.
The entire hull was covered in grey acrylic automotive primer, I use a simple can spray for primer but for all other coats I use an airbrush of a cheap and cheerful hobby shop discount rack variety and I run this via a Tamiya compressor that I link to a battery charger.


Save for the primer coat which is acrylic - the rest of the job I use automotive and or exterior enamels.

The entire lower hull gets sprayed now with a mix of exterior enamel oil based house paint. I get paint samples made up at my hardware store. This is a mix of red oxide and bright red. Note this is a light coat and you can still see some small blemish spots where I have not got complete coverage. With some ships if I like a blemish I'll keep it if its in keeping with how I want the weathering to go, but in the main I will typically coat again until I get a complete finish as perfect as possible and start the weathering with a "blank canvas" so to speak.


Next you see the masked up area (I like Scotch "Magic Tape") as it tends to be low tack - providing you leave a full 12 hours between coats - and what's your hurry - take your time.
The black here is the same deep base semi gloss enamel exterior house paint, except its my own mix of dark grey with jet black..-it looks fairly black here - the paint is still wet.


Here is the rest of Pogy marked up and being sprayed


This side, note I gradually am working the coats on - the grey primer is clearly visible in some spots and denotes surfaces yet to be sprayed

[Slats]

Next fast forwarding a bit - you see the weathering underway.
Grime / scum /water line, upper works to this line is from the red lower hull is a mix of my black and grey, with a slight OD on grey and a touch of purple. The original boats paint colour was initially red all the way to the scum / water line, and these sections pre patrol were then painted black. The black over colour tended to change the finished product to a grey / purple colour - thanks Joel Stadnick for the heads upon this.

Using both dry sponge and airbrush at some distance the colour is weathered and broken up with the addition of some hobby enamel mixes of gun metal and silver. This is lightly (and I mean with all the force of a farting sparrow from 5 feet) applied to given just a tad of blemish in key areas below the water line.




More fun tomorrow night - final detailing and ballasting.....

Best

John

[Slats]

First time wet, with SD on board, in my test and we have a slight list to starboard.
The miracle of somehow first up getting this boat at her surfaced water line, is mainly due to the fact I have already built one of Joel's Permits (which is a tad smaller in OAL and a tad lighter in terms of sail and overall material. That said that boat gave me a very good understanding of ballast, floatation foam, subdriver layout and ballast tank size. I'd be surprised if I was way off on this boats calcs.



J

[Slats]

Yes I am going to take you through the rest of the build, but I had to fast forward to this great photo taken by Brad Van Epps of the Triple S Model Boat Group.

On the left is a C class Sub diving and on the right is Pogy doing the same, note the surface wake as Pogy transitions down from PD - a great photo...





Now back to the build
J

[Slats]

Here you see the linkage and klickon magnet connector supplied by Caswell. The dog leg routes this push rod through fixed eyelet points and runs the brass connection up to the sail planes. The eyelets limit any flex in the line and keep the push rod running true. The magnet end fits against another magnet of opposite polarity linked to a U linkage coming from the aft end motor end cap. Aligning the top of the sub to the lower hull half engages the magnets together and so there is nothing hard about getting the linkage to work upon separating and rejoining the upper and lower hull halves



moving forward you see the push rod through other eyelets and the **** material there is GRP strand laced filler.



I get points off for being internally messy but this arrangement works, and is waterproof. The mess is because I went and installed Joel's excellent supports for the sail plane linkage which unfortunately is not compatible with the new 3.5" Subdriver...more on this, but I installed it so well the first time I need to fill part of the surrounding surface with some glass mat and the filler laced with chop strand was a good choice given the window to the Subregatta was rapidly closing. Yeah but I'm still a lazy bum!

The hose on the left hand side of the sail underside connects to the snort pump. Joel's kit supplied supports for the sail plane linkage only work for the original 3.5" Subdriver that had no forward battery compartment. That old Subdriver used a heavy SLA battery in the wet, but it also meant that Joel did not have to worry about a piece of Lexan tube of Subdriver being located under the mechanical supports for the sail plane. So this mechanism of a simple fixed brass axle epoxied in place with the mechanism rotating around the fixed axle works a treat.

[Slats]

here you see the beginnings of Subdriver assembly. Based on experience with Joel's Permit a ballast tank of 5 and one half inches length proved sufficient for the proper states of dived and surfaced. Note here the lines drawn on the lexan, and the test fit with no O'ring for the servo ballast activation (back motor tray end of ballast tank).



A key missing part at the time of Subdriver supply (only because David did not have the part - not a deficiency in the supply), was a securing nut atop the tank for the schrader (tyre) charge valve. I went off and sourced from an auto supplier some stainless steel car tyre valve caps, and cut these down to make my own locking ring. I think David now supplies a part that comes with your Subdriver kit for this.



Here you see the ballast tank assembled and dunked in the test tank. To do this you can fit your motor end cap with push rods sealing the push rod seals on one end compartment - the motor end compartment is obvious, and seal the battery forward end with the supplied battery end cap. In my case I have spare end caps I use for testing as I figure if there is a leak at this stage I want to minimise what is electrical that could get wet.

It is absolutely imperative that you test every aspect of your assembly of this fine piece of equipment. Follow your supplied documentation and if in doubt ask. David and Mike's gear is world's apart in my view for its simplicity, quality, value for money but most importantly for parts back up.



The tank at this stage showed no signs of leaking.

Push her under and with the valve set to flood you should see a trail of bubbles escaping the top of the tank like this.


I leave my Subdrivers underwater for about an hour held by a cave of house bricks. There should be not one drop of wet stuff in the forward or aft compartments. I then do a pressure test.

The pressure test involves removing the inner overpressure schrader valve of the motor end cap and fitting a silicon tube over this valve. With the ballast tank completely full of water and the whole Subdriver submerged a gentle sustained pulse of air blown by mouth into the system is a good way of seeing if there are leaks. Any air bubbles is a leak area. In my case I found the centre punched machined area of the ballast tank bulkhead was lifting under pressure. This is a little tab in the dead centre of the bulkhead that is sealed by RTV silicon. In fact anothe pressure test I do confirmed this which is filling the gas tank and in water triggering blows. The blowing action was enough pressure to lift this tab and create a leak. Of course this leak is an easy fix of RTV.