Model Boat Mayhem

Please login or register.

Login with username, password and session length.
Pages: [1] 2 3   Go Down

Author Topic: Thoughts on simple model submarines  (Read 14501 times)

Lash151

  • Guest
Thoughts on simple model submarines
« on: February 06, 2012, 11:42:10 PM »

Hi... I was thinking about ways of building a very simple submarine and it occurred to me that the very parallel hull of modern subs especially the Akula class sub would lend itself well to a model made from a large drainpipe or sewer pipe. You could shape the bow and stern and the sail but otherwise its quite a simple shape... It could be a dynamic dive model to keep it simple. The only problem I can imagine would be making an opening in the hull which is subsequently resealable. Has anyone done this or does anyone have any thoughts on this idea?  I would be grateful for suggestions.
Cheers Lee
Logged

Circlip

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,735
  • Location: North of Watford, South of Hadrians wall
Re: Thoughts on simple model submarines
« Reply #1 on: February 07, 2012, 12:05:41 AM »

Good idea, but hang on, have a look at MHS plan MM1155 or MM1210  :-))


   Regards   Ian.
Logged
You might not like what I say, but that doesn't mean I'm wrong.
 
What I said is not what you  think you heard.

Lash151

  • Guest
Re: Thoughts on simple model submarines
« Reply #2 on: February 07, 2012, 12:38:53 AM »

Good idea, but hang on, have a look at MHS plan MM1155 or MM1210  :-))


   Regards   Ian.

Ha... I had a strange feeling I was probably not being particularly clever....Oh well,  I am new to this!
Lee
Logged

Subculture

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,951
  • Location: North London
    • Dive-in to Model submarines
Re: Thoughts on simple model submarines
« Reply #3 on: February 07, 2012, 07:53:32 AM »

It's been done quite a lot. The best way to seal the boat is using a radial seal, e.g. an o-ring. This is the same way wtc/modules are sealed, it's just that instead of the hull free flooding, it becomes the pressure hull, much in the way many modern submarines are configured.

I have a feeling that the plans mentioned by Ian detail a different method, by slicing into the tube and creating a flat hatch from acrylic or polycarbonate which is bolted down with a plethora of nuts and bolts.

Lash151

  • Guest
Re: Thoughts on simple model submarines
« Reply #4 on: February 07, 2012, 08:56:20 AM »

Yeah... I suppose if you built a full length slide out 'deck attached the stern moulding and the tube acted as a sleeve, you could have all the internals easily accessible just by sliding the whole pipe off.... except for the front planes which would have to be built into the bow moulding... I have no experience of subs so forgive me if my ideas are ridiculous!!
Lee
Logged

Guy Bagley

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,222
  • Location: thames valley
Re: Thoughts on simple model submarines
« Reply #5 on: February 07, 2012, 09:09:50 AM »

my submersible is built in a similar way, there is a tube, with an apeture in the rear, this is sealed by an o ring, the rear section is removeable...it also  has  a tray fitted to the inner face it with all the components mounted onto it, - so disconnect the rear section , release the o ring and simply slide all the internal out through the aperture....

so in simple terms.....

model is a static diver using the Norbert bruggen gummi sack principle-

model floats on the surface 50 % submerged with the gummi sack ( a flexible rubber water container) , pump on board water in to the gummi sack- model becomes heavier and down she goes, the gummi sack swells inside the body of the sub as it fills with water - compressing the remaining air left inside the body of the sub ( a sealed tube )

to surface pump the water out of the gummi sack into the lake, - model become bouyant and surfaces..the air insode the hull returns to normal ' pressure'

 as my sub is short and not a 6 foot long brute, i have no front dive planes

on mine i have rear planes directly behind the prop along with a beefy motor so if i need to affect the angle of run once submerged i can do it pretty much  hassle free with rear planes alone... or i can pump water in or out if i wish to go up or down ...

so its best of both worlds, having the ability to static dive if i so wish and using  force to  operate like a dynamic diver should i so wish...
Logged
all in all its just another brick in the wall......

Lash151

  • Guest
Re: Thoughts on simple model submarines
« Reply #6 on: February 07, 2012, 09:24:40 AM »

Ah... thats great, so I'm on the right track then!  I shall pursue this idea. I can understand how you could pump water into a rubber container but when you resurface the boat, what pushes the water back out of the rubber container... is it just reversing the pump?
Logged

Circlip

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,735
  • Location: North of Watford, South of Hadrians wall
Re: Thoughts on simple model submarines
« Reply #7 on: February 07, 2012, 12:08:55 PM »

Your ideas are not ridiculous Lee, at least you're exercising the grey stuff.

  Quote from Hengis Pod, "Yes but my square version of the wheel doesn't run away when parked on a hill"

  Re the guidance bit, a torpedo??

  One design was published In one of the boat comics a few years ago that resembled (AND operated) like an underwater Hydroplane on which the tail feathers were mounted on a Gimbel.

  Regards   Ian.
Logged
You might not like what I say, but that doesn't mean I'm wrong.
 
What I said is not what you  think you heard.

redboat219

  • Guest
Re: Thoughts on simple model submarines
« Reply #8 on: February 07, 2012, 12:13:26 PM »

Logged

Davy1

  • Guest
Re: Thoughts on simple model submarines
« Reply #9 on: February 07, 2012, 12:52:37 PM »

Hi Lee,

What you are suggesting is absolutely right and these kind of methods are extensively used in model subs already. (My ORP Dzik model for one - it is on here somewhere or over on the AMS site.)

It would be worth your while to  have a look at a large number of  model subs in action. Could I suggest going to an event such as the one run by Norwich MBC this summer (See events section, I put on here.)

Keep on with it - you are definitely on the right lines. (i.e simple and cheap - sorry, low cost!)

David
Logged

Subculture

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,951
  • Location: North London
    • Dive-in to Model submarines
Re: Thoughts on simple model submarines
« Reply #10 on: February 07, 2012, 01:11:31 PM »

when you resurface the boat, what pushes the water back out of the rubber container... is it just reversing the pump?

Yep that's it, bi-directional pump, the air is compressed slightly  in the sub as the ballast is taken on, so that helps empty the bag too.

You can use a peristaltic pump for this or a geared pump, both work well but have their pros and cons. Peristaltic pumps tend to be a bit slow compared with geared types but are self sealing , so you don't need a pinch valve to stop the water pushing it's way out, unlike geared pumps which will leak under pressure. It's generally advised you fit a pressure switch on peristaltics- they can reach very high pressures, whereas the geared pumps tend to stall out.

Usually peristaltic pumps are used for models with modest sized tanks/bags e.g. 250ml and under. For larger ballast volumes a higher flowing geared pump is probably a better bet.

Lash151

  • Guest
Re: Thoughts on simple model submarines
« Reply #11 on: February 07, 2012, 01:58:18 PM »

Thanks... I will stick to a dynamic dive system to begin with I think and draw up a plan first... something simple!  :-)
Logged

Patrick Henry

  • Guest
Re: Thoughts on simple model submarines
« Reply #12 on: February 07, 2012, 03:23:08 PM »

Very wise Lee...start off with the basics, and learn as you go. A nice, easy to build and easy to use dynamic dive boat is an ideal introduction into the world of model subs. Build it and use it until you understand what makes it tick, then either add a simple dive system to it if there's room, or build another, more advanced boat.



Rich
Logged

Subculture

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,951
  • Location: North London
    • Dive-in to Model submarines
Re: Thoughts on simple model submarines
« Reply #13 on: February 07, 2012, 07:38:13 PM »

Try and design your boat with a ballast system in mind, if you think that is the way you eventually wish to proceed. e.g. design the tray with free space to allow room for a tank, pump etc.

Really dynamic divers are just as much fun to operate as their static counterparts. Dynamic boats work best when the subject has big control surfaces, and you ballast it down low, so you don't need too much speed to keep it submerged. Some fullsize submarines were designed as dynamic divers e.g. WWII Delfin midget sub and Graham Hawkes Deepflight boats are a couple that spring to mind. You can also look at nature, sharks, killer whales, dolphins, fish etc. These have much larger control surfaces than scale submarines, so you can have something very nimble indeed. Would be tricky to make around a bit of pipe though.

Subculture

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,951
  • Location: North London
    • Dive-in to Model submarines
Re: Thoughts on simple model submarines
« Reply #14 on: February 07, 2012, 09:36:09 PM »

Here is a really excellent site with some free plans for a neat little submersible type craft that could be built from some plastic pipe and plastic sheet. Other materials could be adapted, you could use metal for some parts instead of plastic for instance.

http://pierreyerokine.perso.sfr.fr/atlantis_EV.htm

The boat could be built as a static diver or as a dynamic diver, and you can scale the boat to suit the pipe you use. For instance the use of 110mm PVC pipe would result in a boat 10% bigger, which would still result in a highly portable model under 50cm long, but with a large diameter pressure hull with lots of room for standard size R/C

It looks like the builder had access to a lathe for the construction, but if you don't have one, you can bench fit the components, it just takes longer. If you know someone with a lathe, and they're willing to help out, it will simplify construction greatly for you.

Lash151

  • Guest
Re: Thoughts on simple model submarines
« Reply #15 on: February 07, 2012, 10:03:49 PM »

Hi...
I was messing around with an image of an Akula class sub which struck me as having quite an even (pipe like) Hull... In reality it does taper but if you square it up a bit so as to make it possible to use a tube, it looks OK...

I actually scaled the drawing to 1/90 which would make the model 1300mm long by 150mm beam.... quite big!  This size pipe is readily available.... am I going too large?






Lee
Logged

Lash151

  • Guest
Re: Thoughts on simple model submarines
« Reply #16 on: February 07, 2012, 11:27:39 PM »

A 110mm tube gives a 950mm long model... thats a bit better! 
Logged

Subculture

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,951
  • Location: North London
    • Dive-in to Model submarines
Re: Thoughts on simple model submarines
« Reply #17 on: February 08, 2012, 07:26:15 AM »

Should give you a model of about 15-20 pounds displacement. Russian subs have high surfaced waterlines though, so if you're hoping to emulate that, the boat will need a big tank. For a dynamic diver you will have to ballast it down to decks awash anyway.

Most modern subs are based on a cylindrical centre form, with a tapered bow and stern, so you have a lot of choice. You have subjects like the British Trafalgar, Astute, Vanguard, Swedish Gotland class, or Australian Collins class, German 212, 205, 206 etc. Lots of choice.

Lash151

  • Guest
Re: Thoughts on simple model submarines
« Reply #18 on: February 08, 2012, 08:26:23 AM »

That link you gave me to the little Atlantis sub is good... It shows the construction and internal layout really well.... very useful, thanks.  I also take your point to design the interior leaving space for a static dive system... I am also thinking I could add it later when I have a better understanding of it all....

You were talking about the control surfaces... Would the size of the planes and rudder need to be exaggerated a little, in the case of the Akula, to give it the right amount of maneuverability? 

Lee
Logged

Davy1

  • Guest
Re: Thoughts on simple model submarines
« Reply #19 on: February 08, 2012, 08:54:12 AM »

Could I also recommend having a look at the Charlie Class sub from Model Boats.

I have built 2 of these over the years. A simple to build dynamic diver which I've moved over to static divers using the pumped pressure system. The second one uses a stern opening with O ring seal which works better than a flat hatch. Nice zippy performer see my photo below - and it is basically a length of PVC pipe! I have plenty of more information on this if you want it.


http://www.myhobbystore.co.uk/product/16992/charlie-class-sub-mm1210

David   
Logged

Subculture

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,951
  • Location: North London
    • Dive-in to Model submarines
Re: Thoughts on simple model submarines
« Reply #20 on: February 08, 2012, 09:14:37 AM »

Russian boats tend to have a fairly large turning radius when compared with their western counterparts. You only have to look at the rudder area to see why- half of it is fixed. As such the Russians and countries that use Russian design are the only navies that do this.

The dive plane surface area is probably adequate, but the rudders will work better if they are 'full flying', which means the whole surface area moves, which is more in keeping with boats designed in the West.

On the Sheerline Akula, the upper rudder is scale in appearance, but the lower rudder is full flying, and so are the rear hydroplanes.

Lash151

  • Guest
Re: Thoughts on simple model submarines
« Reply #21 on: February 08, 2012, 10:24:19 AM »

Could I also recommend having a look at the Charlie Class sub from Model Boats.

I have built 2 of these over the years. A simple to build dynamic diver which I've moved over to static divers using the pumped pressure system. The second one uses a stern opening with O ring seal which works better than a flat hatch. Nice zippy performer see my photo below - and it is basically a length of PVC pipe! I have plenty of more information on this if you want it.


http://www.myhobbystore.co.uk/product/16992/charlie-class-sub-mm1210

David   

That looks very interesting... yes, if you have more info that would be good... how did you make the bow and stern parts? I was considering shaping them from wood and coating with resin...
Logged

Patrick Henry

  • Guest
Re: Thoughts on simple model submarines
« Reply #22 on: February 08, 2012, 10:28:17 AM »

Without wishing to confuse poor old Lee any further, but there is another avenue you can proceed down....that of modifying a plastic kit. The Trumpeter Seawolf is a nice easy one to do, plenty big enough, cheap to buy (around 25 ish) not too many scale fittings to knock off, and it builds into a nice boat. Knocking up a wtc is easy, despite what you will hear to the contrary, and you can build a working dynamic dive boat within a week (if you have all the parts to hand) I've built two of these, one was remodelled into my USS Dragonfish Concept sub.


Rich
Logged

Lash151

  • Guest
Re: Thoughts on simple model submarines
« Reply #23 on: February 08, 2012, 12:23:02 PM »

Without wishing to confuse poor old Lee any further, but there is another avenue you can proceed down....that of modifying a plastic kit. The Trumpeter Seawolf is a nice easy one to do, plenty big enough, cheap to buy (around 25 ish) not too many scale fittings to knock off, and it builds into a nice boat. Knocking up a wtc is easy, despite what you will hear to the contrary, and you can build a working dynamic dive boat within a week (if you have all the parts to hand) I've built two of these, one was remodelled into my USS Dragonfish Concept sub.


Rich


Hi Rich....
I like this idea a lot... I had been thinking along the lines of scratch building, as I do with surface boats, but when you add up the costs of a bit of tube and resin etc.... I might as well buy a plastic kit and modify it... It will have the hull surface detail as well which the pipe won't have... Also, I haven't built a kit for ages.. so it will be a nice project... Thanks for that idea.... Can you point me at the kit you're referring to Rich?
Cheers Lee
Logged

Patrick Henry

  • Guest
Re: Thoughts on simple model submarines
« Reply #24 on: February 08, 2012, 12:28:54 PM »

Logged
Pages: [1] 2 3   Go Up