Revell 1:144 212A Conversion

Hi everyone, for your delight and possibly amusement ...

TA DA!!  Nicks Revell 212A build

This started out as many of these things do … a bargain, and don’t we all love a good bargain.

In this case it was a Revell 1:144 212A, with a very heavily discounted price ticket due to it having a very scruffy box.

I’d been looking for some light relief from a scratch build, this looked like it would do nicely and give me a really quite small working sub. There may be more on the scratch build which features 3D printing for some parts, maybe a hybrid piston tanks and ballast bag dive system.

The 212 class was designed for use by the German navy in shallow waters and are able to operate in as little as 17m, primarily the Baltic and Mediterranean Sea are their home waters.
The boats use conventional diesels for surface running but once submerged they switch over to a rather neat hydrogen/oxygen fuel system, the fuel cells sit outside the pressure hull. The drive is exceptionally quiet and the 212’s are reputed to be a bit of nightmare to hunt down, just as well given the tight waters they work in.
They are currently armed with Seashark and/or Blackshark fibre optically guided torpedoes and optionally externally mounted mines.

The full sized 212 is quite small and agile, the 1:144 is tiny and probably quite agile too.

First small issue is I was sent the wrong kit, to their credit they did realise this before it arrived and the replacement was on the way before I'd sent the wrong one back. I have the suspicion that a Airbus A380 wouldn’t work quite so well although the general body shape is kind of submarine shape it is a little small in the beam.

So a small delay while the real kit is delivered, but in the meantime plenty of things to do which I'll list in part 2 in a few days.

First job was to review my stocks of suitable parts, and isn’t it always the case that there is always quite a bit you haven’t got but will need now, or sometime in the future, or it’s just an excuse to get those little oddities that you just want, so it’s all an investment… Honest!!

The hull is small at 397mm long with a beam of 50mm so we are looking at little everything, unlike the ongoing scratch build which looks agricultural by comparison and could eat two or three of these little hulls without any problems!

Motors.. I’ve got 4/5/6 series brushed and similar sized brushless but they’re all a bit big so it’s a trip to e-bay for a few 130 motors. The price is a nice surprise when compared to the last brushless motor and ESC I bought for a FBL heli I recently built, this heli has some superb electronics in the form of a Spirit Flybarless controller. 3 axis gyro’s, accelerometers and all programmable. A huge step from my first heli that had mechanical mixing.

ESC & BEC … Once again I have a few but they are, for this build, ummm massive and way over rated. The smallest I have ‘on the shelf’ handles enough power to melt this baby sub at 40W. A used Mktronics that was just factory soak tested so sold as new-used is duly ordered, at 10W it is small and waterproof so should work nicely.

Servo’s … Space being at a premium pushes me to a few nano feather style 3.5 gm servo’s. The mass and torque from bigger servo’s shouldn’t be needed and again small will work for me.

Mixer … This sub has an X tail so needs a bit of mixing so I’d better throw in a VTail mixer which ought to work. Not ideal as really I ought to use or would prefer a mix at the transmitter, or a computer mixed 4 servo set up, but then I’d need an Arduino in the boat or similar and lack the space so it’ll have to do for now. I really must investigate this OpenLRS 868mhz business and suitable ‘computer’ transmitters.

Battery … I really like the power density of LIPO’s, I’m not so happy with the way it can get out in an uncontrolled rush but again I want small and light so in goes a 7.4V 2S 460mAH battery. This ought to give a quite few hours of play time. If it’s too big I have some small 1S batteries that I’ve have from a few other old projects and put this into the bigger hull for the receiver circuit.

Oh and a set of LEDs for navigation lights to brighten everything up.

As I said this is quite a little hull
All of the images have a 6" ruler shown for scale.

Here is the complete kit of parts, all of 30 something bits!



Here we have the ESC, a servo and tail mixer. The available space is starting to shrink.



The same just bigger against the huge promenade deck ;)



Next more bits to acquire, more decisions to make. Eventually I'll start building

David

Nice looking shed you have there :)

I think that you have a bit of a head start over me on subs!! Liking the WTC sections, experience is going to be a great help in maximising the available volume which is what I'm gaining here. I shall study these pics and see what I can learn from them which I suspect will be quite a bit.

Issues I have at the moment...
No lathe, will have to get a small scale one soon I think.
Limited supplies, well of a suitable scale.
Limited experience, which is why I am here and just those pictures are very helpful :)

Nickj_UK wrote:Nice looking shed you have there :)

I think that you have a bit of a head start over me on subs!! Liking the WTC sections, experience is going to be a great help in maximising the available volume which is what I'm gaining here. I shall study these pics and see what I can learn from them which I suspect will be quite a bit.

Issues I have at the moment...
No lathe, will have to get a small scale one soon I think.
Limited supplies, well of a suitable scale.
Limited experience, which is why I am here and just those pictures are very helpful :)

You've been up-front and honest as to your ability and resources. I'll be equally candid:

R/C submarining is an activity -- if to be pursued to a successful conclusion (and there are many, many half-started projects littering the world) -- reserved for the elite of the r/c vehicle field. This is not an entry-level activity!

I'll advise you as long as you're interested and show progress. Get that lathe and put some time on it turning bulkheads, cones, and hubs; spend your money on good hand-tools; start in with simple r/c model boats; look for and read quality articles on this craft by me and other accomplished r/c model submarine enthusiasts; and step back a few paces and make your first r/c submarine one built from a reasonably sized model kit.

I'm one of the best in this game and the subject you picked -- specifically its small size -- is a misstep on your part. Check out the simple to assemble r/c model submarines offered by R&R and other quality manufacturers.

You're biting off too big a chew with the little type-212. Try again. I'll be here.

David

Mr. Merriman has a point. Often we equate small with easier and in submarines that is not necessarily correct. That being stated, can you make this a small working sub? Yes, but with a lot of work. There are YouTube videos of small subs out there. Many without needing complicated equipment. Some use medicine bottles and such.

A larger submarine size is easier to work on, in my opinion, because of the room offered. You are packing a lot of equipment into your sub and having the space is nice. Revell Skipjack in 1/72 scale has room to build or Bronco's Type XXIII in 1/35 scale.

As far as buying a lathe, you posted where you live and a member here might be able to help you out. Unless you are passionate about turning metal and plastic, it would be cheaper to buy a water tight cylinder pre-designed like the one David shows or makes for the other subs out there.

One of the tubes (last one) David is showing is one he is currently designing, it has a ballast tank. He also makes one without a ballast tank (the tube prior) Making a simple dynamic diving submarine (meaning your forward motion will make the submarine overcome its positive buoyancy and dive) needs less equipment and complexity. It can be done with a 3 channel radio, 2 servos, batteries, motor, and esc (electronic speed controller).

Nickj_UK wrote:........
Mixer … This sub has an X tail so needs a bit of mixing so I’d better throw in a VTail mixer which ought to work. Not ideal as really I ought to use or would prefer a mix at the transmitter, or a computer mixed 4 servo set up, but then I’d need an Arduino in the boat or similar and lack the space so it’ll have to do for now. I really must investigate this OpenLRS 868mhz business and suitable ‘computer’ transmitters....

.Oh and a set of LEDs for navigation lights to brighten everything up.

Hi Nick,
of course the X tail needs a mixer device and the ideal solution is a mixer located within the sub rather than using the mixer of the transmitter. The mixer inside the sub will enable the use of a level regulator that keeps the model on even keel when running submerged at high speed because you will have still access to the diving planes control for the depth inside the model before mixing. So the regulator is inserted in the signal path for depth control only. When using the mixer of the transmitter you will have already a combined Signal.

A level regulator is really recommended, especially when running close beneath the surface, just to avoid the sub jumping like a dolphin. My model, although much bigger (1.3m length, scale 1:43), has a V-mixer for airoplanes installed and a Level Regulator for the depth Signal. A friend had made a short video of the model

By the way some additional Information about the original class 212A submarines. They are in fact powered by a large and powerful electric motor that drives the propeller directly. It is an electronically commutated DC Motor with permanent magnets (the so called Permasyn-Motor by Siemens and it gets the power from the main battery. The battery can be kept on Charge by means of diesel generators (when running surfaced or on schnorchel depth) or by a fuel cell System that enables the sub running submerged independent from the air. So the second boat of the first batch (S182/ U32) ran submerged for two weeks without surfacing. The diesels are not coupled to the Propeller shaft but to the generators only.


Greetings from northern Germany
Klaus-Dieter
("Hermann")

Thanks Herman, That is quite a pool, and a very nice build you have there it drives very nicely.
The mixing with the v-tail units is quite simple and it would be nice to be able to add a little more control but they do work well. The only way to add that control would be a computer transmitter, the down side is loosing a lot of channels.
I had already decided to add a leveller and am going to use one of Kevin McLeod's AD2 units.
I am also looking at arduino's to add an automated control layer for levelling and depth keeping which might be interesting and

I haven't touched this build for a few days as I had a few parts to fit on one of my bikes, that grew from a straight swap that didn't quite fit as I wanted it to which meant I had to fabricate some custom stainless steel linking pipes. Many hours of cutting pipe, welding, grinding and polishing later and done so it is back to the 212 with a little work on the scratch build when time permits.

I decided to make this a relatively quick job so have a WTC from Danny Engelhardt at Maximus Modelbau. There were two reasons for this, firstly I'd need more materials and it would be mostly sizes that I'd probably not use again and secondly to see his solution first hand.
So today a little hull cutting to remove surplus material, gluing some parts together with a few pictures later.

This will handle your x-tail
https://hobbyking.com/en_us/turnigy-v-tail-mixer-ultra-small.html
Do not do it from your transmitter.