The Upside Down?

[Bob Gato]

Most modern nuclear submarine models are split at or near their waterline for interior access..and now with the trend to run servos and other items in the "wet,"-I ask why not build the sub upside down? I mean to access the interior workings from the bottom with the sub in the cradle with the sail and upper structure facing down. This would allow several things to happen-first the connection of fair water planes, rear planes, rudder (Yes I know about the magnetic couplers) also other items such as plumbing and wiring for lights would not normally have to be disconnected leaving dangling control rods and snorkel tubes to contend with. Also what prompted this thinking is the ability to mount IP 67 servos upside down in the wet area which, when in the running attitude will not allow any water to enter thru the output shaft seal (weak link) because of the trapped air inside the housing. Also any water tight compartments with Engel type removable tops or dive boxes with the Ed Tordahl screw cap charging access will also not want to "Leak" because of the trapped bubble inside -It just seems to be a logical answer to the constant fight to keep water out...

[He Who Shall Not Be Named]

My first r/c submarine was built to be accessed from the bottom. I did not like it. This form of access becomes especially problematic if there is extensive deck and sail detail. Upside down servos still get water in them and the interior quickly becomes a tropical rain-forest nightmare -- you'll be lucky if they last two seasons.













Your mileage may vary.

David

[type7]

I have considered it but it means you always have to have a special cradle on hand to work on it and have to be even more careful to not break off the antennas on the sail when you spin it. In addition the sub is ballasted to be right side up not down. One visible join line, or evan 2, doesn't matter when the sub is in the water. I still don't buy having servos or batteries in the wet. Have had enough problems caused by leaks in the wtc to not want to take on extra risk. It isn't very difficult to keep them dry with a o-ring or other seal.

[RCSubGuy]

My first Nautilus was built that way. Just as the posts above, I didn't like it. It made sense for some things, but I underestimated the PITA of having to flip a heavy boat all the time versus just popping the top off...

[Bob Gato]

I have considered it but it means you always have to have a special cradle on hand to work on it and have to be even more careful to not break off the antennas on the sail when you spin it. In addition the sub is ballasted to be right side up not down. One visible join line, or evan 2, doesn't matter when the sub is in the water. I still don't buy having servos or batteries in the wet. Have had enough problems caused by leaks in the wtc to not want to take on extra risk. It isn't very difficult to keep them dry with a o-ring or other seal.

Doesn't just about everyone already have a special cradle for their sub (be it for right side up or not)? and Doesn't just about everyone run their SLA's wet now a days? And soon just about every one will run servos wet, especially when IP68s become as cheap as IP67s are now- AND why would you turn your ballast tank upside down?? you would just access it from the bottom of the sub-you say that you have enough WTC leaks to contend with...Running waterproof components wet will tend to eliminate those annoying thru dry space leak points, like servo push rods and prop shaft seals.

Over the years-I've learned to cross the boundaries of various hobbies-The railroad guys gave us scale hardware and weathering techniques, the dollhouse guys gave us scale figurines and every day items like beer cans and interior lighting. The airplane guys taught us to vacuform plastics into canopies and supplied us with B/L motors and Lipos-now its time to listen to the underwater drone and robotics guys!

[Bob Gato]

And Yea- Good point about the PITA of flipping a heavy sub and breaking stuff... David and Bob I hear you saying..."been there and done that" loud and clear.

[He Who Shall Not Be Named]

And Yea- Good point about the PITA of flipping a heavy sub and breaking stuff... David and Bob I hear you saying..."been there and done that" loud and clear.

Convention is the final arbiter of practice. Hence the equatorial separation of hull halves and accessing things from the top. Bad ideas are quickly dismissed by the Tribe.

The only useful spin-off from the peripheral Crafts is the r/c system and propulsion elements we employ. Other than that, we plow our own road.

Who else is driving the market for water/pressure proof servos? That rhetorical question to make a point: We r/c submarine types are as distanced from professional grade UUV user/operators as hull kit manufacturers are from Cessna airframe makers.

But, I do appreciate your observation about the cross-pollination from the model train, doll, kit-assembly cultures. Long before I was a Mechanic, I was a scratch scale model Builder.

David

[Bob Gato]

Sadly I don't think that a few thousand sub guys are driving the market for underwater servos-the robotics market is. South Korea is investing millions in the industry-and on a happy note us Remoras will benefit from the scraps the fast growing industry is throwing off. A few years back "waterproof " servos arrived and now Underwater servos (for underwater robots) another thing being driven our way is the adorable Arduino-also by the robotics guys. Soon the underwater step motor, coupled with a small computer will take the place of these troublesome servos with their delicate feedback pot system.


Below :the home built ROV sports wet running B/L motors, center: these Hitec IP67 will get us to 3 ft and at the right soon to be released servos boast 300 ft depth.-all in the name of underwater robotics. The colleges and universities offer robotic classes not model submarine 101. I think that we need to think out of the WTC and pay attention to this market-the upcoming years will be interesting.