Project 945 - Sierra I (1/60 scale)

[Rogue Sub]

I have not tried them

I have not tried them under pressure but, they are designed as vaccum pumps

[petn7]

I have not tried them

I have not tried them under pressure but, they are designed as vaccum pumps

They don't hold a vacuum, or at least the two I ordered from Caswell would not hold a vacuum. They only have 2 "pistons" while the larger air pumps have 3, and my experience with them is much better (I'm using 2 of them for an RCABS ballast system).

[Rogue Sub]

Well lets just see what

Well lets just see what Chris has to say about them... Chris where are you?

[cstranc]

Thanks for the warning. I

Thanks for the warning. I should be ok, both ends of the pump are vented outside the WTC and there is no pressure difference across them when they are not running.

[cstranc]

This Sierra made it to

This Sierra made it to SubRegatta 2008 at Carmel

Ok, it looks terrible, and it did not work very well. But it was there, and next year it will be ready....

First, I have to thank everyone for all the help and encouragement at Carmel. The Sierra saw one and a half hours in the water and it felt like it was giving me trouble for about all that time. But it was still in the water (for the first time).

Everyone was so helpful and great to me as I struggled through the problems. Many many thanks to all.

Ok. So what did I learn?

1. Corrosion (with current stupid)
So I tested everything that was going to be out of the WTC by leaving it in water overnight, and going through wet & dry cycles. Silly me.

I did not test how it would survive running underwater with a current going through it. This is the array of electrical terminals as constructed]http://www.subcommittee.com/forum/02 WTCConnects (3).jpg[/img]
And this is them after an hour of being used underwater]http://www.subcommittee.com/forum/03 WTCConnects (4).jpg[/img]

Actually I thought it was kinda cool how you got different colors on the different terminals. In an abstract sort of sense.

Still the corrosion problem ended my sailing time because the main drive started to work intermittently.

Corrosion also hit my thruster motors]http://www.subcommittee.com/forum/04 ThrusterRust.jpg[/img] sigh.

2. Ohh it's so embarrassing to lose a prop
Even the day before I was thinking about this and still did not apply Loctite. Actually I had a checklist of things to do before I sail, and did none of them. Hmm.

3. Side thrusters don't work at speed
This really surprised me. I tested these things in a tub and they pushed a large volume of water. I had heard before that their effect diminishes at speed, but given how strong they were I thought "not on this boat". I was wrong As soon as it slowed down they worked fine.

At high speed the thrusters were in-effective, and the rudder was really sluggish. So when I was heading for a wall the only thing of any use was reverse ( still had a prop then )

4. Buoyancy is different in different water
Quite literally the Sierra hit the water 24 hours before I started driving to Carmel. It was perfectly trimmed in my basement, but over buoyant in the blue waters of the reflecting pool. I really should have re-adjusted there. And added features to make it easy to add a little weight to the model to adjust for local conditions.

5. Wiring takes up space in the WTC
With the drive motor and two side thrusters and my over design of everything I had a lot of wire to accommodate in my WTC. Good thing I was ripping out things like lights, and torpedoes, and everything else by the time I was 2 weeks away from the SubRegatta or I would not have had enough space for all the cables...

Next WTC is going to be much larger.

6. My mouse valve rusted too
Being a very safe person I had a "normally open" mouse for my ballast tank. That means that most of the time it had a current going through it. If I had some major electrical failure (fuse blows) then the mouse would open and bring her to the surface.

That also meant that most of the time the mouse valve was under water it was rusting happily in that current filled environment. It's going inside the WTC now...

7. and many more
I'm not even going to mention things like "do not trust friction to hold the top of the hull to the bottom". Yes that was the Sierra that came back as a half-a-sub and then went out with an elastic keeping it's top and bottom together.


So was it great to be at Carmel? Absolutely.

Did I run around the house and show everyone when I saw the Sierra in the latest SCR? You bet.

Will I be there next year. Ohh yes.

Ohh, the most important thing I learned?

8. The people at SubRegatta are the best

[Rogue Sub]

Chris,

With that much knowledge gained

Chris,

With that much knowledge gained in one weekend I would definitely call it a success! Have fun re over engineering it!

[cstranc]

After mentioning all the issues

After mentioning all the issues I had at Carmel. Well I love this hobby. So I have been re-working the Sierra.

The biggest thing is moving all the electrical content into the WTC (except the LED lights).

The old side thrusters used to look like:

They have been converted to "only pump housing in the wet"


I don't think they will be as effective as before, but I sure need them given the terrible turning circle on this boat.

Given the limited time before the SubRegatta I had given up on the retractable front dive planes. Actually I had created 2 very complex designs that both had just a little too much friction, and did not give me enough space to load torpedo tubes.

One of the things I had always struggled with was disabling the front planes when they were retracted. Many thanks to Johann Sauer. Looking at his dive planes:

With this design when the planes retract they disengage from the servo. It's so simple when you see it...

So that's what I did.

That's the front / side view. I use 5/32" brass rods to retract/extend the planes. They are controlled by a cylinder in the space below the torpedo tubes.

A frontish view with the torpedoes installed:

I really need that space above the torpedo tubes to actually load the primed torpedoes.

Now I have the side thruster pumps reworked, and the front dive planes setup it is time to re-design the WTC...

[slats]

What a beautiful build...anymore on

What a beautiful build...anymore on this thread?

BTW what powers the Torpedoes?


Best

John

[cstranc]

I'm afraid it's on indefinite

I'm afraid it's on indefinite hold. The economy has me spending my spare time working on software development just in case my day job goes away.

The sub it packed away for safety. Every weekend I think about it, then settle down in front of the computer.

The torpedoes are powered by Propel. There was a post on them a long time ago...
http://s181686668.onlinehome.us/phpBB2/ ... hp5?t=5973

[slats]

I am sure you will

I am sure you will get back to it sometime. I do hope things improve.

Nonetheless let me pass on that I think this is a beautiful submarine model you have well underway.

Best

John

[redboat219]

Hi Cstranc,
What's the current

Hi Cstranc,
What's the current status of your Sierra?

[cstranc]

It's out of the box

It's out of the box again, but I'm spending all my time staying employed I'm afraid.

I have to redo all my WTC since it did not work very well last year.

I doubt it will be ready for the regatta this year.

Chris

[Guest]

My suggestion to iliminate the

My suggestion to iliminate the corrotion on critical electrical connections is to use a watertight cannon plug connector.
They are a bayonet twist on system that the Military uses and have gold plated pins and O rings .

Once the wires are sauldered in place there sealed with Goop then rapped or left alone.
I just lable each wire when the connector is closed useing a continuity testor,A- to A- or 1 to 1 or ESC+ to ESC+
These connectors come in a variety of pin numbers or conductors from 1 to 100!
Stinless shell or alloy and plastic.But always the pin holder is a durable rubber or silicone seal that mate the 2 units together in a completly watertight connection.

Some of them I am still using to this day since first installed some 20 yaers ago!
They work very well and are the best way to go in my opinion if you want a reliable easily removable watertight multy circuit conection.

Also if you need to diagnose a problem in a component or wirring , the open pin or female sockets in the connector will give you instant acsses to the circuits or "pinouts."
Also when not in use or used as an external circuit acsses point a cap can be used that has a seal that keeps water out and is made of stainless or alloy,quality components equals a great running sub and is part of my sub safe program.

I have the complete wired connectors removed from looms and are very hard to find in that way.
If interested let me know I have alot of different types and sizes.


just lable and instal,one hole passthrogh and gooped in place does the job or gasket and screws.

This one is in my Alfa 5FT and is a stainless steel one with gold plated pins.
It carries a viriety of voltages very well with no crossover.

Dave

[Guest]

Here are some of them.
http://www.postimage.org/aVlT6K0.jpg

http://www.postimage.org/aVlTbJi.jpg

http://www.postimage.org/gx2a2OEr.jpg

http://www.postimage.org/PqrbFGJ.jpg

http://www.postimage.org/aVlToc0.jpg

http://www.postimage.org/

Here are some of them.














The last 3 pictures shows a charging plug set with sealing cap.

Pm me for deatails

Dave

[wlambing]

Guys,

These are known as

Guys,

These are known as "Amphenol" connectors. Try Googling that trade name.

Take care,

Bill