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Author Topic: Water jets / diving gear  (Read 1465 times)

J.beazley

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Water jets / diving gear
« on: August 05, 2007, 09:34:45 PM »

Seems like the perfect place to post this so here goes.

Has anyone had any experiance with Graupner water jet drives??? how good is the thrust??? would they work fully submerged???

Also for a static dive model what set-up would you people suggest??? would i need airbags/gas tanks??? can i set the maximum depth to say 2 feet??? what fail safes would i need???

Looked for the info on the forum but nothing jumped out at me.
Any info more then welcome.

Jay
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If it floats I'll  build it, if it sinks its a sub either way its in the water so I'm content.

bogstandard

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Re: Water jets / diving gear
« Reply #1 on: August 05, 2007, 10:04:45 PM »

Hi Jay,
The Graupner water jets are very good, plenty of thrust, and I would think they would have no problems fully submerged. The main flaw with them is that they require very power hungry motors, ie Graupner 700 bb turbo. I don't know about the smaller sizes but I think they would be the same.

John
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J.beazley

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Re: Water jets / diving gear
« Reply #2 on: August 05, 2007, 10:15:36 PM »

I was thinking about the 'mini jet' from graupner for use with speed 400 motors, plenty of rpm on them and low drain at the same time.

Jay
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J.beazley

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Re: Water jets / diving gear
« Reply #3 on: August 09, 2007, 08:08:13 PM »

Right need help again, looking to buy 3 of the Lexan tubes with caps 12" x 3.25" ID (3.5" OD). These will be sat side by side in a pre-made polystyrene tray i aquired from work. Apart from the tubes and a suitable water pump what else would i need ???

now heres the theory, if i pump water into the 2 outer tanks she will sink and when i pump the water out using the air from the middle tank she will come back up from the polystyrene bouyancy again???

Jay

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colin-stevens

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Re: Water jets / diving gear
« Reply #4 on: August 09, 2007, 08:21:46 PM »

PanDan is youre man. say it loud it rhyms.(almost)
http://www.pandanmodelboats.co.uk/
very helpful gent.

as for youre theory, sounds good. if only it were so easy. have fun. august model boats did a usefull guide to trimming, more than half the battle
regards
colin
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J.beazley

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Re: Water jets / diving gear
« Reply #5 on: August 09, 2007, 08:38:04 PM »

Been looking at the Pandan site and come across the Engel tanks anyone know how they work??? these could be my answer to save loadsa time.

Jay
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colin-stevens

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Re: Water jets / diving gear
« Reply #6 on: August 09, 2007, 08:43:43 PM »

basically a motorised syringe
try this site,  http://www.modelluboot.de/
regards
colin
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hastings246

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Re: Water jets / diving gear
« Reply #7 on: September 12, 2007, 03:47:30 AM »

Hello,
Try subcommittee.com for ballast tank ideas. There is a concept called RCABS that pumps air from a chamber to a rubber bladder. The idea behind it is the volume of the bladder makes the sub dive and surface. It is a very cheap and safe idea that once figured out works well. There is also KM on the jet drives. They are more expensive but have better tolerances than the graupner line.

Best of luck
Sean
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