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:
And this is them after an hour of being used underwater:
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:
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
It's a great day for R/C sub building.