Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Submarines => Topic started by: Lash151 on February 06, 2012, 11:42:10 pm
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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
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Good idea, but hang on, have a look at MHS plan MM1155 or MM1210 :-))
Regards Ian.
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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
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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.
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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
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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...
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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?
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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.
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Like this, http://www.rapidnadion.com/more-military-vessels.html
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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
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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.
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Thanks... I will stick to a dynamic dive system to begin with I think and draw up a plan first... something simple! :-)
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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
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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.
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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.
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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?
(http://s11.postimage.org/z5ij1ffan/Akula_Class_Sub_actual.jpg) (http://postimage.org/image/z5ij1ffan/)
(http://s16.postimage.org/ulftu362p/Akula_Class_Sub_Plan.jpg) (http://postimage.org/image/ulftu362p/)
Lee
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A 110mm tube gives a 950mm long model... thats a bit better!
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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.
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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
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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://s16.postimage.org/g8uilw975/mycharl.jpg) (http://postimage.org/image/g8uilw975/)
http://www.myhobbystore.co.uk/product/16992/charlie-class-sub-mm1210
David
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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.
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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://s16.postimage.org/g8uilw975/mycharl.jpg) (http://postimage.org/image/g8uilw975/)
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...
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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
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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
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No sooner done than said, Lee...
http://www.cornwallmodelboats.co.uk/acatalog/tr05904.html (http://www.cornwallmodelboats.co.uk/acatalog/tr05904.html)
Rich
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Thanks... I had seen the Revell kits, but not these... They look good for £25! The Revell 1/72 kits also look good and are a good size, but are quite a lot more money...
I shall consider all my options!!!
Lee
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I presume you mean the Gato and the Type V11 U-boat, Lee...not only more expensive to buy, but also having twin propshafts, props and rudders, more expensive to fit out. And all that scale detail...periscopes to knock off, etc.
The SeaWolf needs only a single propshaft and prop and a single motor, there's very little detail to knock off, which makes life a lot easier.
Rich
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Virginia class submarine made from sewer pipe:
http://www.youtube.com/watch?v=0wBa7w7-DZs&feature=youtube_gdata_player
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Thanks for that link... apart from the shiny paint, it looks pretty good... certainly goes well.
Lee
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I rather liked Circlips idea of a radio controlled torpedo. I've seen large working torpedoes, but they're controlled by speed only- no control over pitch or steering. Even WWII designs were capable of speeds in excess of 40 knots, and an 11cm pipe would give you a torpedo at around 1/5th scale with a scale speed of about 20 knots.
Getting it to run well at that sort of speed would present some challenges to the builder, but you could opt to model a slower torpedo, however even the sluggish versions were no slouch, capable of 20-30knots, so you have every excuse to run it fast. Just don't expect it to win any steering competitions!
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Only referred to torpedo as having no front planes for depthing and it having tail feathers only for guidance. Must try and dig out the Hydro type units, they used clear plastic tubes and the gimbel mounts looked like a universal Kort tube.
Regards Ian.
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I'm pretty sure that was an article by Nick Burge from the early to mid-nineties. There were two boats, one big, one small, the big one had a gimballed kort, and the other had a more conventional layout.
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My torpedo hull...four foot in length, all alloy, and based upon the early Whitehead model.
(http://s18.postimage.org/r7kkn4oth/torp.jpg) (http://postimage.org/image/r7kkn4oth/)
Rich
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Blimey... is that going to be a working model?
Lee
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Well, it was going to be, Lee...it's sat in my hall cupboard ever since I got it, I'll never build it now.
Rich
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What version of torpedo was that? All of the pictures of Whitehead torpedoes I've seen were more curvy than that, like in this picture-
(http://s15.postimage.org/q2xv3qlc7/whitehead_torpedo_mk172.jpg) (http://postimage.org/image/q2xv3qlc7/)
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What version of torpedo was that? All of the pictures of Whitehead torpedoes I've seen were more curvy than that, like in this picture-
(http://s15.postimage.org/q2xv3qlc7/whitehead_torpedo_mk172.jpg) (http://postimage.org/image/q2xv3qlc7/)
"My torpedo hull...four foot in length, all alloy, and based upon the early Whitehead model."
Note the word 'based'...
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Hi Lee,
Sorry about the late reply.
Richard is right to mention modifying plastic kits - a good route in - of which I know little!
If you want to get into fibreglass, then making bow and stern cones for a PVC tube is a a good way to start.
Make a male former - turned from wood or foam on a lathe (if you have access to one?!)Then cast a female from fibreglass and then you can make as many as you want.
PM me your email address if you would like me to send you an article on making the Russian "Charlie" Class (Liked Redboats video by the way.)
David
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If the hull is symmetrical, you could make half a plug and mould, cast two halves off, trim them back, flip them around and then join them together. A lathe will make producing round stuff easier, but you can easily get by without one, especially for this kind of work. The other technique quite a few modellers use is the lost foam method, where you glass straight over a sacrificial foam master, and once cured, melt out the foam. The downside is you only get one shot at this, so if you make a mess of it, you have to start over, and you only get one set of parts. I prefer making a set of moulds, although it does double the work.
I know a lot of modellers don't like glassfibre work. I've used plaster moulds in the past for simple shapes. I don't use ordinary plaster, but a special tooling plaster, which you can get from Tiranti's. This stuff set's rock hard in minutes, so you have to work very quickly with it. The finished tools are extremely tough.
You can use epoxy resin, which is close to odourless, and I have found you get a much longer pot life, which gives plenty of time to get the laminate just right. It does cost quite a bit more than polyester resin, but the finished laminates are very strong, and for small quantities the cost will still be small.
The other option is some stuff supplied by a company called 'Smooth-on'. It's called 'Shell-shock' and it's a brushable thixotropic polyurethane resin, with the consistency of gelcoat. This is strong enough to be used without reinforcement, so you just paint two or three coats it into a prepped mould, allow to cure for an hour, and it's ready to be demoulded. It is a bit pricey, but I've found Smooth-on products work really well-
http://www.smooth-on.com/Urethane-Plastic-a/c5_1120_1165/index.html
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I wouldn't recommend the lost foam process. That was the first mistake I made when I built both the "Charlie" and my R class.
You need to do a very large amount of shaping and sanding and resin is hard! (Nigel Edmonds (Mr Fibreglass!) thought I was "misguided" when I described doing it this way!)
And you will usually end up making a female mould anyway, if you like the model, so better to make an easily formed male followed by a female straight away.
David
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Thanks for all the advice guys... I like the plastic kit route but at the same time I have found myself eyeing up bits of pipe wherever I go, so not sure yet!! I might head in both directions at the same time and see what happens!! I do like the scrap and found objects route... last night I found myself in Tesco measuring pudding bowls to see if they would make good nose cones!! The kit is appealing too for precisely the opposite reason! lol
Lee
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With a bit of careful Hacking, you could cut longitudinal sections out of a piece of pipe like darts and with application of heat from a paint stripper type hot air gun you could "Mold" a nose or tail section over a pattern. Beauty about waste system pipes is that they can be solvent welded if ABS or PVC. Beware of Polythene type pipes. You need to "Hot plate weld" those.
Regards Ian.
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Hi Ian,
Great minds think alike?!
http://www.theassociationofmodelsubmariners.com/t139-u-upvc-class
It works quite well and she is still holding together!
David
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Hi... yes thats a good way of doing it... Strangely, I got to thinking about this because I was considering building the whole boat out of wood using the plank on frame method. I just received a copy of the Marine Modelling Submarine Special and in there is an article on a build of a U-202 done almost entirely as plank on frame (with some excellent brass work as well). The plank on frame method didn't seem to meet with much enthusiasm in another thread I posted... I thought perhaps I was being daft by contemplating this method but apparently it is feasible.... but does no one like the idea of using wood?
Lee
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I think you received some pretty objective answers on the pros and cons of using wood. If it's a material you feel most comfortable working with then by all means use it, just remember to seal it well to prevent moisture ingress.
Most model submariners use plastics, composites and metal for construction, because they are inherently moisture proof. The thing to do now is choose a design, and then decide how you want to construct it.
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Personally, I don't like wood and it doesn't like me. I can't even draw a straight line on the stuff, let alone cut one, but it does have it's uses. U-117 was 99% timber built, then coated in resin to waterproof it inside and out, then painted and finally varnished...it never let water in where it wasn't supposed to.
It does make a boat extremely bouyant however...with a boat 108" long, than means a very heavy boat. U-117 weighed 3 hundredweight (whatever that is in these new fangled metric measurements) ready to submerge, it took three strong men to get it in the water and five even stronger men to lift the thing out when she was full of water. I was cursed at shows and exhibitions when I arrived with her in the car....most of the guys would disappear rather quickly when it was time to move the thing!
But, she proved that wood can be used to make a model submarine, and she proved it well. If you can work with wood, then by all means work with it, just remember to keep the word 'waterproofing' at the forefront of your mind as you progress through the building.
Rich
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Well, the design I like the most is the Akula ... and the preferred method of construction is erring towards the 110mm PVC pipe with shaped wooden ends and sail, sealed with resin...
This is what I keep coming back to in my head.... ! 110mm beam makes it about 1/90th scale... about 950mm long.
Lee
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Yes, I really like working with wood... I used to make furniture when I first moved to Norfolk... so its kinda natural to build stuff with wood, but you're right its not the most waterproof material ever! The lost foam technique is interesting though... I used to cast metal parts and I would carve the pieces from hard wax. (which Tiranti sell in large blocks) You make a silicone mould from it..Then you pour metal in one end and the wax pours out the exit hole, leaving the space filled with metal.
Lee
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Yes, I like wood too.
But in submarines - chocolate and teapots come to mind!
David
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Thats a point... you could carve the nose and tail from chocolate!! (The lost Chocolate technique) :}
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Thats a point... you could carve the nose and tail from chocolate!! (The lost Chocolate technique) :}
You silly boys... {-) {-) {-) {-) {-)
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There is a disadvantage to producing reverse tools- if you make a good job of it, people will ask you to make some for them too. Don't say you weren't warned!
At least with the lost foam method, you have the valid excuse of it being a one-off.
A chap I know had one of those little 'Searcher' subs built to the Graham Goodchild plan which was published in Model Boats back in the '80's. Thats was made of wood, although he used plywood instead of balsa. He also made it a wet hull with a little watertight box, made out of- balsa, with an acrylic lid! Never saw it give a moments trouble, although he only used to dive it down a couple of feet. It was a good and fun little boat to drive.
(http://s14.postimage.org/hwu7v00p9/DSCN1334.jpg) (http://postimage.org/image/hwu7v00p9/)
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Good grief, I haven't see one of those in years...I built one from the freebie plan in Model Boats magazine, great little things they were. There was another, very similar boat to that...can't remember the name of it, but there's still a plan available I believe.
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If you're referring to the orange sub which used twin motors for steering, and used a small lunchbox for the watertight compartment and had the scuba diving Action man attached, it was called an 'Action-sub'. I don't think the plans are available anymore.
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Hi Lee,
pm for you about Subcommittee article.
David
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hi David...
Pm'd you back
Lee
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There is an HMS unseen plan that is free dynamic dive but I think could be made in to a static with some modifications to the planed model .. I'm going to have a crack at this with plastic use a one piece strip and curve it, add a few bulkheads and cut the narrowed bow and stern sections all out of one strip of styrene.
I got most of the bits to do it that way already .. Just need time to go but the sheet of styrene ...
I'll post some pictures when I got it done ..
Too much to do to little time to do it all ... I need to stop going to ebay and buying subs .. landing craft ... pt boats two .. four revell kits to build .. when am I going to get the time !!!!!!!!!!!!!!!!! %% {:-{ :((
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Here is my version of "Searcher", many years in the building, still not complete, but getting there. Access to the hull on the original design was via a hatch above the cockpit - I had no faith in my ability to make it water tight so went for removable grp. hatches.
I have forgotten what shade of yellow I used for the hull and can't find a match!
Members of a similar vintage to me and readers of the best comic strip ever might recognise, in the name, the homage I have paid to that publication.