Ohio Class, Ballistic Missile Nuclear Powered Submarine, USS Kentucky SSBN737




PCB & R/C Stuff w. Details, Pictures & Data:

Below you will find pictures and explanations of the PCB. The PCB holds the dual water detector, which monitors water intrusion in WTC1 and WTC2, with automatic surfacing. Also on this pcb is the 2Hz generator for the top light. (I have the rest of the light controlling electronics in a small box elsewhere in the hull.) The PCB is mounted in WTC2.

PCB:

The two red LED's indicate if and where water is detected. (WTC1, WTC2)
The green LED is the power indicator.

Schematics for the water alarms available here.
Schematics for the 2Hz flasher available here.

R/C components, details, pictures & data:

Engine:

The engine for the propeller needs to have a high degree of reliability. Do your self the favor and use a Graupner engine for this task. They come highly recommended, have years of experience in this field, and are not even expensive. After talking to other subbers, I found that
the propeller RPM should be somewhere between 5000 and 6500, and that it's a good idea to use a gear box instead of finding an engine with this RPM. The reason is that using a gearbox gives the engine a little more torque, than if it was directly connected to the propeller. 

I decided to use the Graupner engine "Speed 600BB" (BB for Ball Bearing). The technical data are as follows:

Type: Graupner
part no.
Nominal
voltage:
Voltage
range:
No-load
RPM:
No-load
current:
Current @
max. effic.
Stalled
Current:
Max.
efficiency:
Case
length:
Case
diam:
Free shaft
length:
Shaft dia. Weight:
Speed 600BB M-6310 9.6V 7.2 - 12V 17.000 0.8A 6.6A 55A 75% 57mm 35.7mm 11.9mm 3.17mm 194g.

Gears:

    

The engine is connected to the propeller shaft using two spur gears, so I don't have to worry about any belt breaking. They also gear down the RPM from the engine to a more suitable one for the propeller. The gearing ratio is 3:1, leaving the max. RPM on the propeller at some 5666. Aligning the spur gear is pretty important, as too tight a fit wears and grinds the gear, and too loose a fit results in the possibility that you might brake off a tooth or two. 
Aligning the spur gears are done by knowing the pitch diameter for each wheel. Add the two diameters, and divide the result by two. This is the distance, center to center, that your spur gears must have. 
A simple work-around if you don't have the pitch diameter is done by cutting a narrow slice of ordinary paper, and run it into the gear. Then fit them tight together, and fasten the screws. Now remove the paper, and you're done. Don't forget to lubricate. 

The black oxide steel gears I selected are delivered by RS Components, 
stock numbers RS 745-400 and RS 745-488. Don't forget bore reducers to fit your shafts.

My propeller shaft is supported by a ball bearing with a flange (from an old hard disk) and the stuffing box. This enables me to go without the normally used bearing houses, and offers a low friction fitting, saving battery power an reduces engine heat.

Regulator:

You will also need a regulator in front of the engine, and here I can suggest "Navy V40R" from Graupner, but this is not a critical choice. (The V40R runs on 4.8 -> 16V) Ask your local dealer for advice, and availability. Remember that it must be able to reverse the engine, be temperature protected, and capable of surviving the stall current of the engine. (If you travel forward, and then go directly to reverse without allowing the engine to stop first, then the stall current will be drawn for a short period of time.) The Navy V40R delivers 5.5V (via the BEC) to the receiver and the two servos, so this also solves the problem concerning the voltage for these components. All though the Navy V40R is watertight, and can be placed outside your WTC, I do not recommend this. The reason is that the minimum temperature for some reason is as high as 15*C, a temperature that the water hardly ever is deeper down in my part of the world. Failure in this component will be devastating, as it is the power source for the receiver etc. If, nevertheless, you decide to place it in the cooling water outside your WTC, remember to make the connections watertight as well. 
The technical data are as follows:
Type: Graupner
part no.
Voltage
range:
Current
not cooled
Current
water cooled
Current
< 10s
Battery
Elimination
Circuitry out:
Height: Length: Width: Weight:
Navy V40R 2875 4.8 - 16V 40A 60A 120A 5.5V 3A
(Shortly)
13.5mm 60mm 29mm 30g.

Servos:

The rudder movements are controlled by two individual servos, located within the same WTC as the engine and the electronics etc. They need to be able to push / pull the rods back and forth, and the below described servos should be suitable. The servos for the rudders needs to have a high degree of reliability. Do your self the favor and use a Graupner servo for this task. They come highly recommended, have years of experience in this field, and are not even expensive. I decided to use the Graupner servos "C261" (w. reinforced gearbox). The technical data are as follows:

Type: Graupner
part no.
Voltage
range:
Current
inactive:
Current
active
Force:
Ncm
Force:
Kg
Active
angle:
Speed: Height: Length: Width: Weight:
C261 5125.L 4.8 - 6V 5mA 0.45A 14 1.4 -45* to + 45* 0,14 s/40 21mm 22mm 11mm 8g.

Small switches:

Two small switches are needed to send the signals to "Remote Dive" and "Remote Surface". Again, Graupner has something that we can use: The Graupner Mini Switch. On the remote, two spring operated push buttons are placed, and labeled "Dive" & "Surface" These then momentary enables the two switches at the end of the receiver. More of these might be needed, if you choose to build the navigational light control, as well as other options. The technical data are as follows:

Type: Graupner
part no.
Voltage
range:
Current
inactive:
Current
active
Height: Length: Width: Weight:
Mini Switch 40 3294 7.2 - 14V 0 0.08A 32mm 30mm 15mm 45g.

Bow thruster control:
 
   The left-right movement of the throttle stick operates a small controller for the bow thruster. This function can be mixed into the rudder channel at the remote, thus making the thruster 'automatic', trailing the rudders. The controller for the bow thruster pump is a brilliant little thing from SubTech: the RS-5. 

"The RS-5 Switch is ideal for applications that require reversing the rotation of small electric motors such as ballast pumps, bow thrusters, fire pumps etc. Provides Forwards-Off-Reverse functions. Microprocessor control and low on resistance Mosfet assures reliable, efficient operation. Will control 2 volt - 12 volt motors at a maximum of 5 amps."

Available through Pandan Models, UK.

Type: SubTech
part no.
Voltage
range:
Current
inactive:
Current
active
Height: Length: Width: Weight:
RS-5 RS-5 2 - 12V ? Max 5A 19mm 38mm 38mm ?g.

Transmitter:

The transmitter needs to be able to handle the following functions: Engine forward / reverse, rudder up / down, rudder port / starboard, Remote Dive and Remote Surface. This is 8 functions, demanding 5 channels. In addition comes the control of navigational light, missile / torpedo firing etc, and thruster if fitted. (Note that Graupner uses the term "Channels" somewhat different than everybody else.) The Graupner kit MC12 with expansions can handle what we need. Please refer to the chapter Remote Control Configuration for details.
The technical data are as follows:
Type: Graupner
part no.
Voltage
range:
Freq. Channel grid: Output P: Max.
channels:
Temp. range: Antenna length: Height: Length: Width: Weight:
MC12 Gr4724 9.6 - 12V 40 MHz 10 kHz 2W 7 - 1150mm 75mm 175mm 190mm 950g.

Receiver:

The receiver needs to be able to handle the following functions: Engine forward / reverse, rudder up / down, rudder port / starboard, Remote Dive and Remote Surface. This is 8 functions, demanding 5 channels. (Note that Graupner uses the term "Channels" somewhat different than everybody else.) R700 can handle what we need, and even leave two channels available for future use. The technical data are as follows:
Type: Graupner
part no.
Voltage
range:
Freq. Current Channel grid: Sensitivity: No. of servos: Temp. range: Antenna length: Height: Length: Width: Weight:
R700 Gr3551 4.8 - 6V 40 MHz 13mA 10 kHz 10V 7 15* to + 55* 950mm 16mm 47mm 25mm 16g.


Images of the installed components can be seen here, along with the electronics-, battery- and A.L.T. mechanism section.





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