Need lots of help

[Nb1914]

Do you pack grease into the below

[Nb1914]

The more i look the sub the more questions i have, it looks to me like there is some residual air in the ballast bag, do you vacuum this out otherwise i can't see how the pump would overcome the air pressure build up in the bag ?

[Ralph --- SSBN 598]

Let's see if this explains it.
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Your system is a ballast bag system that takes water from outside the cylinder and pumps in to a bladder inside the cylinder.
The compresses the air in the cylinder reducing the volume of buoyancy from the cylinder.
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You bladder has air in it.
This is actually a good thing when the boat is not being run.
It keeps the insides of the bladder from sticking to each other.

When running your boat this is not really useful.
So, my procedure at the pond is to test all operations of my boat to make sure every thing works.
Then I put the boat in the water and test all the controls except the propeller and water pump.
Once I know all the control surfaces work, I will test the ballast pump.
First, I will bring water in to the ballast bladder.
I do not fully fill the bladder.
I then pump it empty.
This will remove all the water and if you continue to run the pump a little longer, it will remove the air in the bladder as well.

Next, fill the ballast bladder to check to your submerged trim.
If so, again surface the boat and now test your main propulsion motor for forward and reverse.

If all works as it did on your work bench, doesn't always work out that way, you are ready to venture out away from the shore.
I do a few circles in both directions to test propulsion and rudders.
Then I can visually check sail plane operation.
Good to take on the dive.
I do that while the boat sits in front of me next to the shore.
I will submerge the boat and check trim.
If trim is good then it's time to get under way.
The sail planes or rear dive planes will take the boat under while under way.

The day is a good day, if the boat makes it back to shore with no mishaps or water in the cylinder when you open it up on the table.

You pump will pump both water and air.
While on the bench this can be tested by pumping air in to the ballast bladder.
Remember, the pump will not fill the bladder completely with air like it will with water.

If you ballast bladder is put away for the season with all the air removed and the bladder sides are touching, you may need to replace it do to tearing or cracks before you ca run again.

My bladder bag happens to be copied from Tim's boats.
I remove them when I am not going to run my boat.
I use two toy balloons, one inside the other.
I buy a bag of 100.
I prefer the black balloons.





This is a test fill using pump and air.

[Nb1914]

got it thanks, the tearing of the bladder might be why i have a spare bladder albeit smaller

[Ralph --- SSBN 598]

My small 1/144 George Washington uses blood pressure machine bladders.
I have not run that boat much but I have gone through two bladders that cracked just sitting.
Not even in the boat.

I think the rubber is similar to the rubber used in tires.
Tires if not run on the road to cause them to flex will crack and leak from sitting.

[Nb1914]

The bladder looks ok and good quality but i will be sure to watch out for this, also your advice about small vent holes at the top of the middle bulkheads is spot on as even empty the bladder is covering the large centre hole. Now for a really silly question , the DLX2 states it has a reverse sensor ? if subs can use reverse how do you set that up on the radio as i assume the follow:-

Mode 2 transmitter 4 channel
right stick up = sub nose down (dive)
Right stick right/left = sub goes right or left
left stick up = throttle increase
Left stick down = throttle decrease
Left stick left = ballast fill
left stick right = ballast empty

Does the ESC support a middle position setting on the throttle for neutral ?

[Ralph --- SSBN 598]

Control locations.
Right Stick....
Rudder is left and right
Rear planes are forward to dive and back to rise.

Left Stick....
Throttle is forward to go forward and back for reverse.
Throttle is neutral at center.
(Some controllers require a pause at neutral before going in the opposite direction. I am having a hard time with that. I go from forward to reverse and get no reverse until I go to neutral and pause then back to reverse. It also does that going from reverse to forward. I really dislike it.)

Now where we differ on the controls is the ballast pump motor.
I am setup that moving the stick right will fill the ballast bladder and left will empty the ballast bladder.
(My reasoning. If you push the rear planes forward to dive then pushing the ballast stick to the right (pushing) the boat should dive.
Pulling the stick to the left (pulling) the boat should rise then pulling the ballast stick left (pulling) the boat should rise.)

Like airplanes, pulling controls cause airplane to rise and pushing cause the airplane to dive.

It is easier for me to remember this.
===============================
I also have rotating knobs on my Tx to control Sail planes and mast.
Rotating the knob clock wise makes the top of the knob go right or down.
Rotating counter clock wise moves the top of the know left so that would be the same as pulling or up.

[Nb1914]

Thanks Ralph,

I start building in ernest this weekend, i found a nifty failsafe module from "absima" its water proof and simply plugs inline on the channel you want the failsafe on, on power up you simply move the channel to the position you want in a failsafe situation then press the button on the unit and job done.

[Nb1914]

on to batteries, what do you guys generally use or is there no real preference. Lipos / lead acid accumulator / LiFE / LiON. Is it also best to have 2 batteries wired in parallel i.e. instead of say a single 3s lipo 5000MAH install 2x 3s lipo 2500MAH each so if one fails you still have power.

[Guest]

I wouldn't even consider anything other than Lithium tech these days for batteries. LiFe is more stable and a safer form of tech, you have a little higher upfront cost, plus a bit less energy density than lipo, but apart from that a good technology. I've been using lipo batteries in models for years without incident, but there have been problems, usually caused by abuse or bad manufacturing, but you wouldn't want to find out the hard way.

Wouldn't advise paralleling batteries up, as that can lead to issues with one charging the other if they get a bit unbalanced in operation. Just choose a single pack at the system voltage you wish to use, capacity shouldn't be a problem with lithium, as they're much higher energy density compared with other batteries.

One last point, whatever system you choose, make sure you fuse your boat. Failure to do so can result in an underwater incendiary, should something go short circuit. ESC's can be especially prone to this. If you're concerned about diversity of the power system, create separate power buses for the RC, drive motor and ballast tank, with each item fused independently.

[wingtip]

that's some good info from sub culture and in my current (life long) project im using a 4s battery 5,000 mah... I have two of them but on plan on using one pack at a time but I do have a parallel connector so that one feeds the esc for the piston tank and one feeds the esc or the drive motor... but I had totally forgot about a fuse so I may have to make another connection to throw in a fuse...

Any preference on type of fuses you do or don't like sub culture??? And why...

[Nb1914]

all good info, i think i will stick to LiPO as i have already have a good balance charger. Probably 3s 11.1v, wingtip in the past i have used car fuses

[QuarterMaster]

In the end like anything else, it's your application that dictates it. PERIOD.

As a large boat guy, I have, and always will use the venerable 12V 7Ah SLA. The tech is tried and true, I can buy them at Home Depot, Lowes, even Walmart. They have sufficient mass for the boat so it doesn't look like a toy bobbing in anything other than a small ripple, and my 1/48 Skipjack USS SHARK running a Speed 600 Motor? I get bored after 2-3 hours of running. I have NEVER ran that boat down. Even my 1/96 Scale James Madison Class Boomer GRANT runs for 2+ hours using the same WTC Motor setup on a 12V 3.5Ah SLA.

If I'm away from home at a meet and my charger craps out, (Murphy's law is a clear and present danger in my life) I can run to a local hardware/autostore and replace it.

Don't get me wrong, I'm a techie nerd, and am all for new battery tech. I'm just saying consider ALL options for a specific application.

For my 65-96" models, SLA fits MY application.

Not for my 1/96 Blueback.

BTW, I run my SLA's wet, in the free flood area.

[Nb1914]

i did look at SLA batteries as they are very cheap. Do they have to be mounted upright ? , i have seen a 12v 0.8AH/20H SLA thats quite small for only 6quid !

[Nb1914]

Do you see any issues using threaded metal rods to clamp the WTC together to prevent them popping off under pressure, I'm not sure if there is potential to interfere with Radio reception using 40Mhz.