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Author Topic: An easy to build WTC for r/c model submarines.  (Read 16855 times)

Subculture

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Re: An easy to build WTC for r/c model submarines.
« Reply #25 on: November 15, 2008, 11:01:33 AM »

You can use a peristaltic pump with a bag. This pumps water into the bag in a bi-directional way, and requires no valves, as the pumps are self-sealing.

This system is used in Norbert Bruggens 'Delta' and the Thundertiger Neptune.

The disadvantage of these pumps, are that they're rather slow in operation- medium size models tend to pump between 200-400ml per minute, therefore they're better suited to craft with a low freeboard, and small ballast tank requirements.

You would also need power to surface, as the pump has to be run both ways.

Unfortunately, all the ballast systems have pro's and con's. The closest to nirvana IMO is a combination of a compressed air system, coupled with piston tanks for trim, unfortunately it's also the most complex to engineer.

das boot

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Re: An easy to build WTC for r/c model submarines.
« Reply #26 on: November 15, 2008, 03:40:41 PM »

Here's the Mark 24 reincarnation of my WTC...completely different to the pics above. It now has a small screenwash pump filling an internal ballast tank as Ramesh described earlier (yes I know, I haven't made the baffles for it yet), two of the servos and the rx are installed along with the drive motor and Dave @ Action is sorting me out an esc, a pump switcher and more than likely a fail safe as well, although I haven't told him about that bit yet.   :o

There's space at the forward end for the battery pack (I hope I measured it correctly...)

It's getting there...


Rich
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polycell

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Re: An easy to build WTC for r/c model submarines.
« Reply #27 on: August 14, 2009, 03:24:24 PM »

How is the dive unit coming along Rich?  I'm thinking of doing the same for my recently acquired Sheerline type VII, its a bit of a learning curve at the moment so any tips, advice on where to buy bits would be helpful. 
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submate

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Re: An easy to build WTC for r/c model submarines.
« Reply #28 on: November 04, 2009, 06:39:10 PM »

Can anyone advise me where I can get Acrylic tube from at a reasonable price?
Looked at various suppliers all requiring 2m lengths @ 150 ish :-)

Thanks
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Subculture

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Mankster

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Re: An easy to build WTC for r/c model submarines.
« Reply #30 on: November 04, 2009, 07:03:20 PM »

Can anyone advise me where I can get Acrylic tube from at a reasonable price?
Looked at various suppliers all requiring 2m lengths @ 150 ish :-)

Thanks

That must be cast acrylic your looking at.
I get all my acrylic tubes from ebay too.

Greggy1964

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Re: An easy to build WTC for r/c model submarines.
« Reply #31 on: November 04, 2009, 11:14:23 PM »

Just a thought on internal air pressure.

They guy that taught me how to build boats years ago used a car tyre valve complete with rubber from a tubless car wheel and tyre. At the pond side just prior to setting sail he's attach an ordinary bicycle pump to the valve and give it a couple of strokes to pressurise the interior.

This was used to inflate the external bladder via a valve operated by the dive vanes if I remember correctly
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Desi

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Re: An easy to build WTC for r/c model submarines.
« Reply #32 on: November 05, 2009, 01:26:14 PM »

Hi,
I would like to add my two cents worth to this post...

Only use polycarbonate/lexan tubing for WTC as the acrylic
will crack and all your electronics will be DONE and you could loose the boat as well.

It is a small price to pay...trust me you do not want to find out the hard way

Acrylic is great for a ballast tank
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Subculture

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Re: An easy to build WTC for r/c model submarines.
« Reply #33 on: November 05, 2009, 01:54:36 PM »

Why do you say that, acrylic works very well for WTC's. It's used almost exclusively for clear dive modules here in the UK. PC/Lexan tubing is nigh on impossible to source, and far more expensive.

Acrylic has to be worked more carefully, as it's more brittle. But it's also more rigid than lexan, which is a good thing for subs as it's less likely to compress with increasing depth.

Desi

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Re: An easy to build WTC for r/c model submarines.
« Reply #34 on: November 05, 2009, 03:52:11 PM »


Acrylic, PVC Pipe are all great for a BALLAST TANK as they can be easily replaced and are cheap.
They do not have any electronics in them.

The electronics/guts inside a WTC are conservatively speaking over $500
when you have a reciever, 3 servos minimum, ballast pump, APC Leveller, usually geared motors.
You want to make sure you keep the water out... a lexan tube will never fail you, it is super strong
and can take any kind of punishment, depth etc

I have heard some horror stories... besides in most cases a WTC can be built into the hull,
then all you need is a lip and lid made out of lexan sheet like I have done in my U141 (earlier post)

http://www.smallworldmodels.com/parts.htm

Hope all this info helps!
Best Regards,
Desi
Toronto

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Turbulent

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Re: An easy to build WTC for r/c model submarines.
« Reply #35 on: November 06, 2009, 06:43:59 PM »

Why do you say that, acrylic works very well for WTC's. It's used almost exclusively for clear dive modules here in the UK. PC/Lexan tubing is nigh on impossible to source, and far more expensive.

Acrylic has to be worked more carefully, as it's more brittle. But it's also more rigid than lexan, which is a good thing for subs as it's less likely to compress with increasing depth.

Agreed Andy, I use Acrylic for my WTC & never had any issues & chris uses PVC for his units.
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