Topic: Alternative ways to make a model submarine work (Read 12455 times)

polobeer · « **on:** August 30, 2009, 06:13:56 pm »

I'm currently wondering if there are alternative ways of making small plastic kit submarines "work" without RC gear? I would like to make a model that could at the very least dive and surface but not necessarily move forwards or backwards, although this would be nice as well. The reason I ask is because there are so many nice little sub kits on the market (too small for RC internals) that it would be nice to see if they could be made to dive and surface a bit like the Doyusha submarines. Has anyone ever attempted this rather unusual idea? By the way, I've not been in the pub all afternoon if you were wondering!!

Simon

Martin (Admin) · « **Reply #1 on:** August 30, 2009, 08:59:55 pm »

Do I remember a backing soda submarine of yesteryear....

john s 2 · « **Reply #2 on:** August 30, 2009, 09:05:14 pm »

Dear Simon .Baking powder will gas when wet.Construct chamber with powder to top allow to fill from bottom.If sub ballested ok will sink then surface? Have also used sparkets soda siphon cartridges to supply gas using valve of
bottle with servo to op .Just ideas John.

polobeer · « **Reply #3 on:** August 30, 2009, 09:20:33 pm »

Cheers for those ideas Martin and John. I think Airfix did a sub which had this system. If you have any other thoughts let us know!

Simon

HMS Invisible · « **Reply #4 on:** August 30, 2009, 09:23:24 pm »

Plain old radio control seems easier by comparison!
http://www.modelboatmayhem.co.uk/Modellers/Paul%20Cook/1ndex.htm

polobeer · « **Reply #5 on:** August 30, 2009, 09:40:57 pm »

Yes but at a price! Sadly I don't have money to burn or the technical expertise necessary to put an RC sub together. I am also throwing out a challenge to see if someone can come up with an alternative to RC to make a small model sub dive and surface. I'm sure it's possible. Anyway here's a link to the Airfix sub mentioned above:

http://forums.doyouremember.co.uk/toys/6388-fizzing-submarine.html

Simon

dodgy geezer · « **Reply #6 on:** August 30, 2009, 09:47:55 pm »

Quote from: polobeer on August 30, 2009, 09:40:57 pm

Yes but at a price! Sadly I don't have money to burn or the technical expertise necessary to put an RC sub together. I am also throwing out a challenge to see if someone can come up with an alternative to RC to make a small model sub dive and surface. I'm sure it's possible. Anyway here's a link to the Airfix sub mentioned above:

http://forums.doyouremember.co.uk/toys/6388-fizzing-submarine.html

Simon

The old Sutcliffe steel model boat range of the 50s included several clockwork submarines. These had the forward planes set to dive, and were expected to be sailed in a purpose-made boating pool (there was at least one in every town then). They would dive, hit the bottom and stop, surface, accelerate again and dive, until the clockwork ran out.

The other much-used trick was to set the bow planes to dive, tensioned with an elastic band. The planes were linked to a vertical rod with a flag on top (or perhaps the periscope). As the boat dived deeper, water presure on the rod forced it back and at some point the planes went level again.

HMS Invisible · « **Reply #7 on:** August 30, 2009, 10:02:09 pm »

The academy sub comes supplied with that porpoising system.

I don't agree that special skill extra cost is required to upgrade it to rc.Read the magazine article in Marine Modelling if you would like such a sub but think it is tricky.
Perhaps you were looking at the large Darnell with ballast systems.
I was referring to Paul's 18" long plastic kit which has motor and prop shaft supplied

HMS Invisible · « **Reply #8 on:** August 30, 2009, 10:37:44 pm »

Pics don't seem to show

http://www.modelboatmayhem.co.uk/Modellers/Paul%20Cook/1ndex.htm

Pictures sorted, Martin

redboat219 · « **Reply #9 on:** August 31, 2009, 02:50:40 pm »

Here are a couple of examples made by Japanese modelers

http://www.excite-webtl.jp/world/english/web/body/?wb_url=http%3A%2F%2Fhomepage1.nifty.com%2Fmizuyon%2Fmizumono%2Fp_oyasio%2Fp_oyasio.htm&wb_lp=JAEN&wb_dis=2

http://www.excite-webtl.jp/world/english/web/body/?wb_url=http%3A%2F%2Fhomepage1.nifty.com%2Fmizuyon%2Fmizumono%2Fsea_v%2Fsea_v.htm&wb_lp=JAEN&wb_dis=2

polobeer · « **Reply #10 on:** August 31, 2009, 03:01:38 pm »

Many thanks redboat219,

Two very interesting articles, particularly the first one, although it's not clear how this example works exactly (forgive my ignorance).

Simon

Subculture · « **Reply #11 on:** August 31, 2009, 08:34:50 pm »

It's very simple. The boat is trimmed to dive via the rear hydrovanes. These are connected to a deflector plate which is mounted above the conning tower.

Once the boat reaches a depth where that plate starts to submerge, pressure on the plate pushes it back, which actuates the rear hydrovanes to surface the boat. When it surfaces, the deflector plate emerges, and the hydrovanes revert back to the dive position and the boat begins to submerge again.

This cycle keeps repeating until you run out of pond, and the boat effectively porpoises along close to the surface.

Turbulent · « **Reply #12 on:** August 31, 2009, 10:20:05 pm »

Quote from: Subculture on August 31, 2009, 08:34:50 pm

It's very simple. The boat is trimmed to dive via the rear hydrovanes. These are connected to a deflector plate which is mounted above the conning tower.

Once the boat reaches a depth where that plate starts to submerge, pressure on the plate pushes it back, which actuates the rear hydrovanes to surface the boat. When it surfaces, the deflector plate emerges, and the hydrovanes revert back to the dive position and the boat begins to submerge again.

This cycle keeps repeating until you run out of pond, and the boat effectively porpoises along close to the surface.

and looks crap

Wasyl · « **Reply #13 on:** August 31, 2009, 10:33:59 pm »

What about filling the little sub with Salt,it,ll sink to the bottom, then the salt will dissolve, and up she comes

Wullie

Subculture · « **Reply #14 on:** September 01, 2009, 07:24:20 am »

Would that work? I think salt is very close to the density of water, so when it dissolves the boat may remain submerged.

polobeer · « **Reply #15 on:** September 01, 2009, 08:49:42 am »

Keep the ideas coming folks they are all very interesting! The salt suggestion is a nice one Wasyl. Perhaps we should run a competition to see who can come up with the most ingenious and simplest method to make a non RC sub work, with photos of each sub?

Cheers
Simon

Tug-Kenny RIP · « **Reply #16 on:** September 01, 2009, 11:08:11 am »

Perhaps we could try it with Springers ???

Plenty of room inside to fit all sorts of designs (sophisticated machinery or cheap chemicals!!)

Just a thought

ken

Wasyl · « **Reply #17 on:** September 01, 2009, 11:32:49 am »

From memory,water with a high salt composition,makes sinking nigh impossible,i.e."Dead Sea"therefore if the little sub is ballasted with salt then put into a fresh water pond,providing the little sub,has some boyancy then it will surface,once the salt has dissolved,as its only the weight of the salt that will take the sub down,

Wullie

polobeer · « **Reply #18 on:** September 01, 2009, 07:06:01 pm »

Hello Wullie,

So if you ballast the sub with salt only (in a container with small holes to let water in very slowly) that would be the only ballast you would need to make the sub dive? It's certainly an interesting concept and would be easy to set up. I suppose the sub could be designed to be pulled apart in the middle, before each dive, then you could place the drilled salt container inside and then put the two halves of the sub back together again. Obviously the sub itself would need to have small holes drilled in it as well. If the sub was big enough a small watertight motor could be placed inside as well and a long length of cotton attached to the stern of the sub to retrieve the model. Such a sub could be used in calm seawater without any adverse effect! The little Hobby Boss subs might be good candidates for the salt container only concept (if hollow, as they are pre-assembled), and the Bronco subs for the salt container and motor idea. Any takers out there?

Um!
Simon

sheerline · « **Reply #19 on:** September 01, 2009, 10:05:50 pm »

The salt idea is an interesting one. Salt added to freshwater will give the water a higher specific gravity.. more dense. If a ship sails in salt water, it will actually float higher than it will in fresh water due to the increased density. The extreme example of this is the dead sea... so salty and dense that it will support objects which would normally sink. The same applies to submarines, when sailing submerged, ballasted neutral for sea water, the sub will tend to sink if it enters a freshwater area, as in a river outflow to the sea.
Likewise, I imagine if a container or hopper in a model sub were filled with salt and open to the water, that salty wetted area may actually be a little heavier than it would have been had it simply been filled with freshwater, therefore when the salt has dissolved, theoretically the sub should float to the surface. The hopper wound need to be open at the bottom as well as the top. As the salt dissolves into the water, it will make the water more dense than the surrounding freshwater and if not vented at the bottom, it would simple lay in there and not go anywhere, therefore a small aperture somewhere in the bottom would allow this dense water to drain away.
Worth a try!

polobeer · « **Reply #20 on:** September 01, 2009, 11:00:58 pm »

Most interesting Sheerline. So am I right in believing that when the salt gets wet it makes the sub lighter than the surrounding water which causes the sub to surface? Forgive my ignorance!

Cheers
Simon

sheerline · « **Reply #21 on:** September 01, 2009, 11:26:40 pm »

No, if my thinking is correct, the sub should be heavier with the salt on board and will get lighter as it dissolves and seeps out as a salt water solution.
Try an experiment at home and prove my theory cos I may be wrong (I have known it to happen once or twice

)
Measure by volume an exact amount of fresh water in a container and weigh it using some fine digital scales. Empty the container, now add two or three spoonfuls of salt and add water to the same level in the container and weigh it again. I am sure you will find it heavier, this means if the salt were allowed to dissolve and leak away, being replaced by freshwater again, the container would reurn to the same weight as before. If your sub just floats without salt init and sinks when it is added, it stands to reason that it will float when the salt dissolves. The biggest problem will be the length of time salt will take to completely dissolve away so it could be a long dive time.
I am pretty certain this correct but would be intersted to hear from those more knowledgable than I.

Martin (Admin) · « **Reply #22 on:** September 01, 2009, 11:42:26 pm »

From Ian...

polobeer · « **Reply #23 on:** September 02, 2009, 07:24:57 am »

Cheers Sheerline and Martin; all of this is like something from the journals of the Special Operations Executive (SOE - "The Baker Street Irregulars")! Most ingenious! Could someone explain how the Academy motorised sub works (like the one microgyros converted to RC)?

Simon

HMS Invisible · « **Reply #24 on:** September 02, 2009, 11:25:27 pm »

The pictures were from the Upscope series in Marine Modelling(Spring 2003) where Paul converted the 1/150th XXI to RC.My contribution to the conversion was miniscule.You need a keen eye to spot it
The kit is complete (batteries not included) and uses the same porpoising system as in the Robbe Seawolf and those Jap subs.
It should be plain enough but I still have the instructions to my Type VII which I can email to you.

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Author Topic: Alternative ways to make a model submarine work (Read 12455 times)

redboat219

Wasyl

Wasyl