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R/C combat submarine

R/C Submarine modelers

R/C combat submarine

Postby buttsakauf » Tue Aug 07, 2012 12:40 pm

This being my first post I will offer an introduction. I am an active duty sailor stationed in Charleston, SC. I have been stationed on a submarine and am currently involved in Model Warship Combat (see: mwci.org). I have built combat models and now am looking to combine my passion for all things submarine with my hobby.
I can miniaturize all components sufficiently to fit them in a scratch built 1/144 scale hull. The trick in this hobby is that a portion of the skin of the hull is made from balsa wood so as to be penetrable by BB sized projectiles. Meaning it gets a hole punched in it and turns into a mud dart. I know this might be a hard concept to grasp. There are no failsafes to surface the vessel. The vessel will have to be retrieved off the bottom if hit.
I am thinking a "dry hull" is my only viable option. I can get it to seal and be watertight. Then when hit it flood and sinks. I can waterproof any electronic item... no WTC needed for the preservation of equipment. It would just take up valuable weight anyways.
My biggest roadblock is the submersion system. I only need the sail to break the water's surface as far as ballasting purposes go. I would actually prefer that nominal draft is actually decks awash (0.5" depth+-). I need it to be able to maintain a depth of 1 foot maximum even when static. My ballasting system doesn't need to be big. Just reliable. I was thinking that a ballast tank at each end of the sub with a high pressure "micro" gear (or peristaltic) pump to push water in and compress the air in both at once would work. If my depth starts changing (compressed air pushing water out through pump), I can just "bump" the pump to get it back where it needs to be. I was also thinking I could use very small pumps with bladders and a pitch controller too. A boat that small (3lbs submerged) will be EXTREMELY sensitive to small ballasting changing (i.e. a bladder shifting by 1/4").
Mike
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Re: R/C combat submarine

Postby salmon » Tue Aug 07, 2012 5:39 pm

This is new to me, so let me have fun day dreaming and throw ideas out.
The hull can be balsa and in a dry hull configuration. Inside the hull is a sealed tube with all electronics a wtc. ballast changes can happen inside the wtc using RCABS (which spell check made crabs). The dry hull area is weighted such that once pierced, it takes on water and sub will make a final decent.In my head I can see it working......
Thoughts from the sages????
If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.
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Re: R/C combat submarine

Postby JWLaRue » Tue Aug 07, 2012 6:41 pm

Yea, I think that using a "dive module" inside the sealed, outer hull is a better way to go. Given your surface trim requirement, it isn't going to take very much water to sink the boat. :) Plus, fixing the sub after being sunk will be a much easier and (in the long run) much less expensive.

Question: how would opponents be able to fire BBs at you if you are always submerged?

I'd also seriously consider using a single ballast tank or bladder. It's not very easy to get a good fore-aft trim in a model sub, let alone one that small. A single ballast tank located at the c.g. is all you'll need.

-Jeff
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Re: R/C combat submarine

Postby buttsakauf » Wed Aug 08, 2012 12:36 pm

A couple more notes:
-Ships move at well above actual scale speed. (It is more like DSS or Dynamic Simultude Speed)

-Dive planes should be of use to level sub.

-It will be armed with a single BB cannon. So I will have to surface to a "vulnerable depth" to fire my gun. Attacking ships can penetrate a couple inches of water and inflict damage at close ranges with their guns.

-My cannon will shoot one spurt of 15 BBs using a small precharged to 140psi accumulator and a QEV (Quick Exhaust Valve). I thought of using a small co2 cartridge but it takes up too much weight and will affect my ballast due to the change of states (liquid to gas).

-A WTC is of no use to me. I individually waterproof electronic components with conformal coatings (3M Skotchkote). There should be little to "fix". I even pot my servos in epoxy/ coat the boards. I imagine my generic mabuchi 280 size motors will fail periodically (once a year or so). A little preventative maintenance goes a long way. On a larger model I would be inclined to do a WTC for sure.

-I have been sinking models for 8years :wink: The only thing to do after being sunk is dump the water out,patch the holes in the vulnerable skin, and reload/recharge the gun... As long as you have built it properly.

-A single properly placed ballast system seems like a better idea.The goal is a "pitch stable" vessel that can surface and dive multiple times. It seems like intoducing a small quantity of water into a well placed bladder via a peristaltic pump could serve my purposes. It could pump in and out with no check valves. A smaller but higher capacity gear pump with check valves could also be effective. I don't want to use centrifugal... I hate priming issues. I will have no air volume to draw from so it seems like an RCABS type system is not good for me.

Mike
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Re: R/C combat submarine

Postby salmon » Wed Aug 08, 2012 1:00 pm

O.K. - what can we help you with then? It sounds like you have a good grasp of what you want to do.
If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.
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Re: R/C combat submarine

Postby buttsakauf » Wed Aug 08, 2012 1:04 pm

Another thought... This sub will need to be self righting. It will get jostled alot by other models and potentially be in some rough water. So open bottomed ballasting systems are probably a bad idea. The only thing "scale" will be the looks. The performance will not be in any capacity. Faster is better.
Mike
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Re: R/C combat submarine

Postby buttsakauf » Wed Aug 08, 2012 1:16 pm

I was really wanting to verify the validity of my ideas. The biggest obstacle that I had no experience in (except real world) was a ballasting setup. It seems that a small change in ballast is all that is going to be needed. I have no experience in that field... same as the majority of my hobby. I have only seen one sub in that hobby and it was a dynamic diver. It porpoised alot and had difficulty lining up shots. I think a small ballast setup with dive plans to trim fore and aft using a auto leveller will help me greatly with the issues that plagued my friend.
Mike
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Re: R/C combat submarine

Postby Scott T » Wed Aug 08, 2012 1:54 pm

Seems like making a watertight hull of balsa will be tough.
A pressure hull surronded with a balsa shell sounds easier to
accomplish. The shell might be able to be compartmeted to be part
of your flotation; which when holed would subtract from your
bouyancy.

Since you are using gas to fire your amunition then it might
be simpler to use gas for blowing your ballast. If you used
some type of pump that puts pressure or vacuum inside a
balsa watertight hull it might explode or implode your hull;
depending on the strength of the balsa wood.

If you sail in murky water you might think of rigging a
rescue bouy system.

Scott T
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Re: R/C combat submarine

Postby buttsakauf » Wed Aug 08, 2012 3:02 pm

Watertight balsa skinned hulls are a bit of a challenge. I have alot of experience doing it. Silkspan and dope with the appropriate paint do a very good job. I had thought of using a slightly larger co2 system and not needing a pump to move ballast. I have some very unique vintage 2oz co2 cylinders that could very well work. However I have a feeling that I would tend to pop up like a cork. I do have some minature flow metering valves that could help though. The trick is that if I get rolled over I dont want to lose my air out of the tank. I was gonna rig up a piezo buzzer with a water sensitive switch (of my own design using a tip-120 and a mini relay) for recovery. I enjoy free diving and can spend 30sec+ on the bottom of 10-15ft water. Here is a drawing of a rough idea using the right sub I will be modeling. That is the USS Argonaut. I chose it because it is one of the biggest allied subs... and the Surcouf is hideous imho.
Mike
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Re: R/C combat submarine

Postby Ramius-II » Thu Aug 09, 2012 9:37 pm

Hi Mike:
Maybe this will assist you with you project. I have been working on sensors for such things as depth and 2-axis tilt and others. One recomendation is to use a "PIC" (Programmable Intergrated Circuit) for controlling the hardware. Here is a link to the software for depth which is accurate to 1/2": http://www.picbasic.co.uk/forum/showthread.php?t=16457 I have not posted the tilt sensor yet.

Best, Ed
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Re: R/C combat submarine

Postby buttsakauf » Thu Aug 16, 2012 2:50 pm

WOW! That is really neat. The programming portion/ code is WAY above my head. I have never messed with microchips. However a depth control device would be outstanding! I would need a lot of help finding the right sensor, hooking it up, etc...
Mike B
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Re: R/C combat submarine

Postby Ramius-II » Thu Aug 16, 2012 3:22 pm

Hi Mike!
It is really not that difficult and very rewarding! The sensor and all details are part of the link I posted here.

Best, Ed
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Re: R/C combat submarine

Postby Diederick44 » Wed Aug 29, 2012 4:29 pm

i would like an update please , did it work and what happend to the battle sub ? ? I am also going to try and build a battle submarine and i have a few ideas on the basic circuit system
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