RC Submarine: Russian Akula Class

[Marpek]

Hello everyone!

Here I present my latest r/c toy, RC Submarine!

Maybe you may wonder why a submarine?? You can`t see her beneath the water but that`s the whole idea isn`t it... Stealth??

Anyway, after get poisoned by Bboy few months ago (yes, months) and had taken the plunge to buy a submarine lit from Tower (thanks to Bboy, Bro KM also got himself his first naval warship kit as well ) and that`s how all it got started. The Sub Kit is from Dumas, the AKULA, and American brand that produced plastic vacuum formed or wooden scale r/c or static boats. Coincidently Bro Chai also have this kit before me, and started to get motivated to build up again after being laid up for a while after he first started to build and did not get to complete her...

About The Model:



This is Dumas' Radio Controlled Sport Scale Akula Sub.
Designed from the Russian nuclear attack sub.


This model represents a current AKULA class nuclear attack submarine
as in service with the current Russian Fleet. The model includes details
such as conning tower, periscope/snorkel/radar masts, cruciform tail fin
including the pod on the upper tailfin that houses the towed sonar array
which is a distinctive feature of current Russian attack subs.

FEATURES

Easy to assemble w/all necessary running hardware for its single
screw drive line.
Designed for pool use.
Enhanced building manual will walk you step by step through the
successful completion of your model.

INCLUDES

All the molded plastic parts to build the sub, all running hardware,
building manual.

REQUIREMENTS

One Dumas 2004 6V motor
One 7.2V battery pack
One ESC
One Three channel radio with 3 standard servos
Assorted building equipment and paint if desired

SPECIFICATIONS

Length: 33"
Width: 4" (the width of a ship is also called the "beam")

COMMENTS

This is a DYNAMIC model, meaning it surfaces or dives via the action
of the bow and stern planes, not by flooding and emptying of ballast
tanks like a real submarine. It is intended for use in a pool or
other enclosed body of water to a depth of 3 feet (.97 meters)


The stock model is designed for Dynamic dive as explained above. Initially intention is to build as per stock configurations, but after constant researching in the web with Bboy, I decide to convert to Static Dive mode by D.I.Y (ready components for Static Diving is very $$$). Static Diving means she dives like a real sub, by flooding the ballast tank to displace air/ increase weight and thus will sink. To surface is the opposite. To achieved this, there are few ways to do it, namely; via ballast water tank with water pump (my version), motorized piston tank and ballast air tank. It`s going to be very technical to explain in every details for the functions, so I attached below useful links for reference:

Model Submarine Diving Technology: http://www.rc-sub.com/resources/index.php5

Popular R/C Sub online shop: https://sub-driver.com/

In short, the main heart of a R/C Sub is it`s Water Tight Compartment (WTC). WTC are costly as they were mostly built to order as a component, or complete with a sub kit. Most of them were hand made and time consuming to assemble and thus after gathering much information's, I built my own WTC at a much lower costs at expense of time. Enough writing, below following posts will explain from the start to current status (still not maiden her yet, but soon)...

Parcel arrived at orpit which brightens up my day...







Nice blueprints



First off, hull preparations...

[Marpek]

Next... sand, sand and sanding in order to have a good nice clean fit for the top and bottom hull halves, as well as the top sail...









Trial fit stock WTC into hull...

[Marpek]

Continuing on the hull, drilling and filing draining holes on the hulls, and couple of long and painstaking hours built...











Instructions is to cut off the top front portion of the top hull for removal purposes to access the interior components, but I chose to cut the bottom so that I have a clean look on the top half hull instead. The 2 halves were then mate by means of magnets supplied at rear tail portion to hold them together.







Install top and bottom tabs for hull alignment plus the magnets. Same here, did not follow instructions but own ways for more integrity mating of the hull halves...



Next, designing a WTC. Basically consists of an acrylic tube with end caps. Sealing off water by means of o rings. Below example of a typical r/c sub a static dive WTC with piston tank...



My own designed WTC. Consists of s 80mm OD x 3mm thick clear acrylic tube. End caps were 5mm thick with holes drilled for S.S stud bolts to hold them together on the outside. Bro Chai did his end cap with thicker 10mm material which imo is better as with this thickness, the studs can be inside the WTC. probably my next upgrade!



Final design selection...





Got my acrylic from local acrylic supplier in Ubi...





Trial fit stock servo tray inside wtc, and another teaser pic of a stimulated piston tank as well...





Due to space constrain for the upcoming bladder bag space, will be getting a 6V Sub C saddle pack NIMH battery from Hobbyking for this project, and will place in front of the WTC...

[Marpek]

Construction of WTC components...



















Motor shaft seal: Motor shim spacer and rubber boots for servo mounting. Idea is to mimic the mechanical seal found in some industrial pump products... and it works when testing in a tub!

[Marpek]

Fabrication of servo tray and installations of electronics. Please note for underwater operation, it is believed that a 2.4G system will not work. Only analog radio in this section...

Specs:

Min 400-540 size brushed motor x 1
Min 4 Ch FM radio (prefably computerized with failsafe)
Mini servos x 2 for rudder and elevator
6-7.2V ni-cd or nimh battrey x 1
Brushed ESC x 2 (throttle and pump)
Failsafe unit for pump incase lost signal
Water pump × 1













More shopping for WTC components:

Bladder Bag from Rc Sub Workshop...









Push rods boots from ebays...



2-way rolling pump from Aliexpress...



Currently have some issues with the performance of the pump. Flow rate is too low and slow. Now in searched for an upgrade motor to test again...

Below a GWS 40mm ducted fan 6 bladed impeller to replace stock sports 2 bladed prop...

[Marpek]

Now comes the exciting part... painting! grey base coat applied...







Adding details like antenna/ radar and reshape the front dive panes and rear rudder for scale look...









Hooking up the push rods, and add extra tabs for the hull halves to achieve cleaner look...





Last stage, final coats of Tamiya Matt Black and Matt Dull Red...































That`s is all folks. Will update any progress soon, especially sorting out the pump issues. Meanwhile, she`s still can performed dynamic dives even without the pump but with the custom WTC as per initial designed. Bro Chai`s Akula with similar WTC has successfully maiden today at Sengkang Pond. Below are some shots of his nicely done up boat...









In the pool...



Come join the navy... feel the poison... On most Saturday morning there will be a meet up to play our boats from scale warships to racing F1, sailboats and other types of fast crafts! Soon there will be another large 1/250 scale battleship Yamato (besides mine), plus the Tamiya 1/350 scale CV-65 USS Enterprise joining the Naval Fleet to re-construct the Pacific War during WWII.

[wyetuck88]

Awesome!!!

[boolean21]

Very powerful build thread!!!

Good reference for future submarine builds!

[Marpek]

Updates:

Add some decals onto the boat:







All done in couple of hours!


Next, motor for the rolling pump. Have swap out stock 12V motor to a typical 400 size motor for Heng Long Tanks. Probably 6-7.2V standard. Test run on the boat`s 6V main batt, it took around 1min to fill up the required ballast to submerged. Below pic showing my home made pond made of cardboard and black trash bag filled with water. But she still needs some trimming to get the dive level, as of now either she submerged by the bow first, or the stern first. Testing's also show water ingress into WTC due to compression and depression within the chamber when the bladder bag expands and contracts. Tried many ways to prevent this but results still not improving.





She actually sinks!


First maiden her with no success last week as met with radio glitches and rudder issues. The EDF fan impeller doesn't do it`s job well as it`s not supposed to .This was easily solve by extending the receiver antenna outside the WTC, and waterproof the copper wire ends.

New brass prop, a true scale 7 blade for submarines costs USD24.00 from ebays!





Today's 2nd maiden was quite a success. The static diving behavior is the same as the initial tests, however, when she goes to the bottom pond bed, a slight reverse pump (to surface)she can level up to it`s sail or periscope height and hovering beneath the water. if to surface more, will exhibits again the bow raise first. Anyway, it`s a real treat to watch her sailing slowly in stealth mode... sometimes loose sight of her as she sometimes dives itself deeper when add too much throttle. I wasn`t exactly paying much attention at the controls but just too engrossed... needs more practice sailing a sub! Here are the pics of the day!











Silent Hunter approaching...







Russian sub spotted by recon plane...



Russian sub seen in the  community water parks...





That`s all for the pics, didn`t took too many. Overall performance of the static dive mechanism built out from scratch works well for a start, except for the water intrusion and low performance water pump issues. Also, am very happy with the results, and there`s no questioning why not building another scale submarine kit.. it`s all really worth it!

Looking into improving the ballast system by upgrading to compressed air ballast system which has minimum WTC pressurized issues, and probably a much simpler setup, except needs to keep a can of compressed air canister (used for airbrushing) on hand to charged the  in-built mini air cylinder tank. Advantage is could have a quicker and balanced leveled diving, but cons is limited amount of surface intervals over tank charge, but I can lived with that!

Hoped the next chapter of this sub coming soon... so stay tuned, while I`m soon building my next scale boats as well!

[boolean21]

Very nice work and poisonous!!!

[Marpek]

Thanks bro!

[oceanic]

nice scale look! The propeller so swee! Great job.

[Marpek]

Thanks bro!

[redboat219]

Maybe you could try using a winshield washer pump to fill a close ballast tank. A pinch valve prevents water flowing out when the pump is stopped. Moving one way activates switch to turn pump on. Turning other way vents tank.

[Marpek]

That sounds like a good idea bro... pressurized vessel tank. Wonder those pumps pressure is high? Have read for prezzurized vessel tanks, pressure could be as high as 4 bars or more to compressed the air within when turning on.

I have also thought of a rather radical solution, which is adding a small balloon outside the WTC and connected to it as well. Whenever pressurized , air in the WTC displace into the balloon and when surface, the air in balloon will compensate back into WTC...

[redboat219]

You could also use the washer pump to pump water out of a vented tank. A separate flood valve (or even the pinch valve) control water entry into the ballast tank. A vent tube located at the top of the permit air to go in and out.

[Marpek]

Thanks for the tips mate, will look into the pump options available.

Theres a member in our group haveing the same Akula model and same wtc (actually we build together) but with different setup, having 2 x pumps with stock stuffing box epoxied onto the endcap. It works well for the pumps and eliminate water intrusion problems as well...

[redboat219]

Will post photos and links when I'm free.

[Marpek]

Looking forward.

[redboat219]

Site admin won't let me post link for 7 days as i just registered on this site

[redboat219]

I'm also doing an RC submarine build. It's a 1/144 Trumpeter Kilo with 2" sub driver. Been on and off with it for 5 years already. Time to finish it!

[Marpek]

Sounds great!

Looking forward to see her completed, and post your build of the sub driver!

[redboat219]

[img=https://2img.net/h/s31.postimg.cc/munxa7pjr/Fit.jpg]

[redboat219]

Hi. Hope the OP still here. Just want to ask regarding endcap o-rings. Did you cut a channel in the endcap to hold the o-ring in place or is it just on surface?

By the way, here is a photo of my 1/144 Kilo. Still unfinished but working on getting it wet.

[Marpek]

...just super glued the Oring to the rim of the cylinder end in place.

[redboat219]

Thanks bro. Any updates?

[Marpek]

Hi Bro, How's your Kilo?

Currently my boat only recieved new pump recently, plus new radio. Also ditched the fully submerged dive mode and switched to Snort mode to overcome the pressurized leaking issues so the WTC will always have neutral pressure within.

Recently also come across a website (zero bubble submarines) selling small scale cold war era Russian subs which is tempting to build again...

[redboat219]

Hi. Still unfinished. Been busy at work. Hopefully will finish it this year.
Yes, Zerobubble does beautiful models.
I acquired a 1/96 Russian Uniform Class "Spy sub" from another builder in Australia

[Marpek]

Wow cool! Another nice subject sub.

Keep it up man. Especially the kilo. Perhaps one day we go dive together!

[Marpek]

Embarking new Akula class submarine project with a 3D printed hull.

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