Building the little Kilo submarine

[MFR1964]

Some more work on the SD, i did counter a problem,





In this configuration i started with testing, everything worked, but the motor wasn't spinning at full speed, at the end i found out it was a 12V motor instead of a 6V motor.



Had to breakdown the complete configuration, found a 6V motor and glued it low tech on the bulkhead, if needed it can be replaced by braking the glue joint.



The new build-up with the 6V motor, added the steering rods and shimmed the shaft of the motor to 4 mm (using a 4 mm lipseal)



Since i use 1,5 mm rods, i had to alter the standard seals for the shafts, by drilling a slightly smaller hole you compress the O rings, after that you glue them down, giving you a good seal on the steeringshafts, did this trick some time ago on the type XXIII SD, still working without problems.


Manfred.

[redboat219]

Romel,

those LPB's are rated 6V, not really sure why you have the 3V variant.

Thank you for pointing it out.

The one's I initially saw were rated to 3v but yes there are 5v variants available.

[He Who Shall Not Be Named]

I was about to say that. I've run them at 12V for short bursts with no issues at all...

Same here with the 3V units. But, being the Conservative guy I am, I do (but not always) put an 11 Ohm resister in series with one of the LPB's input wires.

[MFR1964]

Same for me Bob, have them inside the V80, running them on 12V also, the one venting the ballasttank has a 11 Ohm resistor inline, this one has to work longer for venting the ballasttank, the other is used for the peroscopes, only short bursts needed.

Manfred.

[RCSubGuy]

Romel,


PS: Did a checkup on my stock, all those LPB's are rated 6V, not really sure why you have the 3V variant.

I was about to say that. I've run them at 12V for short bursts with no issues at all...

[MFR1964]

Romel,

I've used in the past two ways, one is, tie it into the 4,8 volt from the BEC, second is, use a resistor into the circuit of the LPB motor, for 12V it will be around 11 Ohm, for 6 V around 5 Ohm, this wil limit the voltage.

Manfred.

PS: Did a checkup on my stock, all those LPB's are rated 6V, not really sure why you have the 3V variant.

[redboat219]

Manfred, with your initial plan of activating the lpb with a mechanical switch, those micro pumps are only rated to around 3V, how were you going to power the pump?

[MFR1964]

Romel, Using a switch is a usefull low tech solution when you don't have enough channels on your receiver, had the complete LPB laying around, enough channels on the receiver, the kilo will be build as a simple pool runner.

Manfred.

[redboat219]

Kinda like the mechanical switch.

[MFR1964]

Had to order a new ESC, found a complete LPB unit, deleted the switch on the servo and got me a motor which will fit inside the SD



Made some tubing for managing the ballast system.



Glued them down with some 2K epoxy and taped them down for curing.



Once the glue was cured removed the tape and got me this clean look, don't like those hoses living in the wild, another set of tubes will be added for the antenna-wire.



Made a make-shift frame for holding the servo's, just enough room to get the motor in.



The shaft will be sealed with a lipseal, those inserts above are made by David, got some in the spare department.

Manfred.

[MFR1964]

Romel,
Saving me the hassle of making more grooves for another set of O rings, due to the design of the SD you can reach everything without removing the ballasttank bulkheads.

Manfred.

[redboat219]

How come you opted to glue the ballast tank bulkheads to the inside of the SD than use the retaining screws?

[MFR1964]

Grooves for the O rings are done, digged in the spare part drawers and got me some usefull parts from the past,



Making this took some time, each time you have place the O ring and to fit the bulkheads on the tube, you're aiming at having that small black line, knowing the seal is good.



Both bulkheads fitted, and the bulkheads placed for making the ballasttank, usually i make a dryfitt time after time before i glue things down.



First step in glueing, the SD had those holes, for screwing down the inner bulkheads.



Those are items found in the spare parts draw, the lever for sealing the ballasttank and the collars to fasten things.



Decided to go the way David did, a simple micro-switch to start the LPB, this way things can be done with one channel instead of two.



Same story with the valve on top of the tank, freshly sealed with RTV, retrieved from the spare parts, i'm that kind of person which like to save things for the future, you can never have to much spare parts.



All components in place, yet another dryfitt, still have to place/glue the cable conduit, in a later stage all will be adjusted to function properly


For now i have to see what else hides in the spare department, need to source a small ESC, E-motor, receiver, LPB and some extra servo's


Manfred.

[MFR1964]

Glued together the disks which will be the bulkheads and did some work on the lathe



Glued both disks for both bulkheads and let them cure for 24 hrs, less curingtime will give problems with turning them down.



At first i turned them down to the diameter of the tube.



Second run, making them fit inside the tube still without the groove needed for the O ring.





It should fit like this, a little play between the bulkhead and the tube, want to avoid a tight fit, in the end the O ring will seal off the tube.



Fitting the bulkhead and the first part which will form the beginning of the ballasttank.



Both inner disks pre-pared for the conduit which will hold the power cables and the cables needed for the front servo.

Now i have to make the grooves for the O rings, and do some testing to get them just right for sealing off the tube, this will be done step after step, i've got me one attempt to get it right, otherwise i have to make me some new bulkheads.


Manfred.

[Das Boot]

If anyone gets the idea of building one after Manfred gets done, I have one new in the box I’m wanting to get rid of. Check out the for sale section here.