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Author Topic: submarine questions  (Read 2077 times)

gyronuts

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submarine questions
« on: June 03, 2009, 06:07:18 PM »

Hi,
     Just bought a dynamic dive sub and have a few questions. Model is 44" long and powered by an 8 cell 3000nimh pack running rudder and 2 x motors. planes are adjustable by screws on the underside of the hull. so to the questions:
1. How much current should the motors draw out of the water?
2. How does one make a waterproof hatch to allow charging ( and venting during charging ) of the nimh batter pack? Is there a commercial version availible?
3. Where does one get a waterproof power switch for the hull?
4. What model is this?
5. What type of submarine is this ie U Boat type?
6. I need a speedcontroller with BEC, does it need to have reverse?
7. What motors were fitted to this type of model? 380s,400s and 6v,7-2 or 8.4?
8. Will  I be able to use 2.4GHz radio as if it submerges I would kep it near periscope depth?
Thanks.
Away on holiday Saturday for a week so no internet access after Friday night.
Bill
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Mankster

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Re: submarine questions
« Reply #1 on: June 03, 2009, 06:45:04 PM »

1) It depends on what motors a are fitted, if its geared, the resistance in the drivetrain and the propellers you are using.
2) You can use some form of a bottle top, anything from a plasting coke bottle to a jar top.
3) Maplin sell more of the one you already have there and larger covers for the full sized toggle switches too.
4) Not sure, it it a fibreglass hull?
5) Looks like a Type VII
6) No it doesn't need to have reverese if you only want to go forwards.
7) Dont know, but low rev 380's on direct drive  should be fine. You can run whatever voltage the motors are desgined for. I try to stick with 12v to keep the current down.
8) I would stick with 40MHz even for a dynamic diver.

craftysod

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Re: submarine questions
« Reply #2 on: June 03, 2009, 06:55:53 PM »

From what i have read,regarding 2.4 ghz on subs,its a no.
The ariel lenghts on the receivers are very short,and even part submerged you could lose signal,
and you cant extend the ariel lenght on them.
Mark
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gyronuts

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Re: submarine questions
« Reply #3 on: June 04, 2009, 03:45:16 PM »

Hi,
    Thanks for the responses. i have been to Maplins and now have a waterproof switch, picked up a speedcontroller but still wondering how to make a watertight seal to disconnect/ charge the battery without having to remove the main screwed down clear cover. i have a jar type screw top seal on my 1 metre yacht but space is at a premium on the sub due to the hull cover on top. any ideas?
Bill
Also a contentious issue. It is said that 2.4 ghz does not work on subs. however, I intend to mainly cruise on the surface withtheodd run with the conning tower in view and maybe even a quick submerge to about 6". Has anyone actually tried spectrum in such a sub?
If so what happened. If it goes into failsafe the dynamic diver must shut off power and surface surely?
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sheerline

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Re: submarine questions
« Reply #4 on: June 04, 2009, 04:48:51 PM »

If you are intrested, I can make you one of these, I make them for all my subs. The gold insulted connector terminal screws into the watertight container and the bellows and socket fit to the battery. When fitted together, you will have a fully waterproofed battery cnnection. I might add, I never use any type of switch on my units and simply pull the rubberised terminal off to disconnect everything or push it on to bring it all to life. It's one less hole in the dive system and one less component to fail/leak if you do it this way. Pm me if you are intersted.
Chris
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amdaylight

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Re: submarine questions
« Reply #5 on: June 05, 2009, 05:50:47 PM »

As far as the radio is concerned even when you are running on the surface it is under water because 90% of the sub is under water. The receiver with its very short antennas will be under water in the water tight compartment with waves splashing over it, the only way that a 2.4ghz would work is to have the receiver in the sail above water and then you could not even submerge then because the receiver would get wet and that would be the end of the receiver. The way that 2.4ghz receivers have been designed you can not hook a whip antenna hooked to them.

If you have a fail safe on board with a 2.4ghz radio system in may be working most of the time due to water running over the deck

Sorry for a sub the only radio that will reliably work is on on the FM band. <:(

Andre :-)
over yonder in Portland Oregon
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gyronuts

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Re: submarine questions
« Reply #6 on: June 14, 2009, 08:19:22 PM »

Hi,
   thanks for the response. I have drilled a hole in the forward hatch and epoxied in the top of a 2 litre milk bottle with screw top. I will let you know how it goes!! bill
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gyronuts

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Re: submarine questions
« Reply #7 on: June 19, 2009, 01:53:53 PM »

submarine ready to go. Completed bath test and held underwater for 10 mins. Also set up whirlpool for 2 mins just a slight leak probably through motor shafts. great..Bill
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gyronuts

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Re: submarine questions
« Reply #8 on: June 24, 2009, 03:44:35 PM »

well finally got the nerve to sail it on open water. Ist attempt quite goods but a syringe full of water removed from the "watertight hull"
resealled the rear "hatch".
2nd go great hit the bottom a couple of times . sails generally nose down tail up when underwater.
Hardly any water this time.
 3rd go much better longer "forrays" underwater turn caused boat to be level but straight had the stern still high.
Losts of water this time!!!.
Intend to reseal all the hatches with silicone ( there were covered in vaseline) before I start playing with the planes.
 Certainly caused a bit of interest. Perhaps they were anticipating it not coming back up!!!
Camera battery went flat so only limited shots.
Bill
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gyronuts

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Re: submarine questions
« Reply #9 on: June 24, 2009, 06:55:26 PM »

Hi,
 As I commenced the cleaning up of the model to seal the hull I decided to try to reconnect the moveable front planes by the addition of a servo. Does anyone happen to have a plan or instrucrtions for a krick uboat? Do I need to make the rear planes moveable or is that too difficult. I can adjust the rear ones  with a screw when the model is  out of the water. Thanks. Bill
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gyronuts

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Re: submarine questions
« Reply #10 on: June 26, 2009, 01:53:51 PM »

anyone got any ideas of how much movement i will need for the front planes? does anyone have a copy of the krick manual?
thanks. bill
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Mankster

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Re: submarine questions
« Reply #11 on: June 26, 2009, 02:52:42 PM »

You'll need to connect up the the planes to a extra servo inside the WTC, same way you would hook up a rudder. I'd connect up the rear planes and leave the front alone for the moment.

gyronuts

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Re: submarine questions
« Reply #12 on: June 26, 2009, 04:45:59 PM »

So you would advocate leaving the front fixed and operate the rear by servo. Is that what you mean?
I was thinking of a servo on the front set to the rh stick down/up and another servo for the rear operated by the l/r on the throttle stick so i could trim it using the stick trim.
would that work or just leave the rear plane alone and set out of the water depending on how it sails?
thanks. Bill
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Mankster

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Re: submarine questions
« Reply #13 on: June 26, 2009, 06:32:04 PM »

If you have room for 2 extra sevos in there then you can go ahead get both front and rear planes working. This way you could use a pitch controller on the rear and manually control depth using the front plans. This would be the prefered way and give you the most control.

gyronuts

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Re: submarine questions
« Reply #14 on: June 26, 2009, 06:54:20 PM »

not sure if I would have enough space for a pitch controller. Model only 44" long. Who makes pitch controllers ? bill
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Mankster

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Re: submarine questions
« Reply #15 on: June 26, 2009, 07:57:36 PM »

They are about the size of 2 postage stamps  :-))

gyronuts

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Re: submarine questions
« Reply #16 on: June 26, 2009, 08:03:38 PM »

how does it work? would I just connect the rear planes to the unit and leave it to its own devices? Thanks. bill
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Mankster

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Re: submarine questions
« Reply #17 on: June 27, 2009, 12:21:41 AM »

Yes thats it, or if you have a spare ch, you could also connect it to the Rx for fine tuning and manual overide.

gyronuts

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Re: submarine questions
« Reply #18 on: June 27, 2009, 07:41:17 AM »

do you know if anyone has  a secondhand one for sale? Bill
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gyronuts

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Re: submarine questions
« Reply #19 on: July 02, 2009, 09:01:58 PM »

well , motors replaced and two new servos, front and raer planes on seperate channels at the moment. bought some aquarium sealant for the hatch seals so will see whether that makes the model completely waterproof. bill
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gyronuts

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Re: submarine questions
« Reply #20 on: July 15, 2009, 04:54:48 PM »

got a pitch leveller but will wait to see how easy it is to control the sub before fitting.
 the other sub , a coastal u boat lookalike, was sailed today!!!! Bill
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