1/96 SEAWOLF Turnkey Build, Part-6

Of course the 1/96 SEAWOLF chronicled here would not have gone anywhere without the electronics and mechanicals inside needed to power, control, and change the displacement of the submarine. And those chores fall on a device I invented some fifteen-years ago (a device that has been much copied, without any significant attribution, I point out!): the water tight cylinder, or WTC.

WTC's were not new at the time I 'invented' my version: I remember seeing a picture of one in a British magazine, a publication that was dated, 1967! However, to the best of my knowledge, I'm the first guy who made these units commercially available on the world scene. I also lay claim to the fact that I'm the guy who popularized the concept of making WTC's removable; a feature that permits the enduser the option of using one WTC to operate any number of r/c submarine hulls. I'm the first! I'm the inventor.

Now ... if only you Johny-come-lately WTC manufacturers would be so gracious as

to give credit where credit is due.

Hey, you WTC manufacturer's out there: Each time you use the term

WTC, how about a big public thank-you to one, very special, David D.

Merriman lll????..... You're welcome!

The basic WTC-3 is a three-inch diameter Lexan tube -- capped at each end and divided internally with cast resin bulkheads -- provides the only dry-space within the model. In these spaces are mounted the receiver, servos, speed controller, motor and other electronics and devices that need to be kept dry. There is a dry space forward, where the rechargeable battery (same type as used by the r/c car crowd) is accessed, and a dry space aft, where most of the other goodies are kept.

A note to you Cabal Report recipients:

I'm just about ready to send out the second DVD Cabal Report. This one will be # 6 of the video series. If you have not received a video Cabal Report and want to be on that list, send me your address. I'm asking that you note the cost of shipping when the DVD arrives, add three bucks and send the fee back to defray coasts. This will lighten my financial burden as I produce this stuff ... and, vital to my health, your compensation will keep Ellie off my back (she's the official D&E Miniatures bean-counter, and cruelly administers our operation with an iron clad, tight fist).

The WTC-3 used aboard this model of the SEAWOLF is pretty much stock -- other than the inclusion of an APC (automatic pitch controller) linkage to set the angular displacement of the unit, for adjustment of the models 'zero bubble' set-point. The

WTC contains all the propulsion, power, control and variable ballast elements needed to animate the model. Being removable, the WTC is easily maintained, repaired, and used aboard other r/c model submarines of the wet-hull type.

Note the external bow-plane pushrod atop the cylinder: used to engage the pusher-plate of the bow plane linkage -- those two elements engaging when the upper hull is placed atop the lower hull, just prior to operation.

I favor a gas type ballast system aboard my WTC's. An onboard Propel container holds enough liquefied gas for nearly twenty blow/vent cycles. A servo mounted within the after ballast tank bulkhead controls the vent and blow valves located within the eleven-ounce capacity ballast tank.

The special watertight seals used for all the WTC pushrods are of my own invention as well. These seals are formed by encapsulating rubber quad-seals --suspended within the mold by slipping them over removable bore forming cores --within polyurethane casting resin bodies. These type seals replace the labor intensive machined brass seal bodies and cup seals formerly used. My resin bodied seals are used for all axial (linear) motion shaft sealing jobs, and are used to make watertight the stern plane, rudder, bow plane, APC angle adjuster, and ballast system pushrods.

Three types of watertight seals used aboard my r/c submarines: Upper left is a Clippard 'cup' type seal. This is a pressure sensitive device, that is to say that the design of the 'V' shaped seal provides an ever tightening seal between shaft and seal body with increase of the differential pressure, i.e., the deeper the model goes, the tighter the sealing force upon the shaft. Cup seals are suitable for both radial and axial traveling shafts. And I must acknowledge the originator of SubTech, Skip Asay, as the man who introduced me to the use and utility of the cup type watertight seal. I use a cup-seal to effect the watertight union between WTC motor/gearbox output shaft on all my WTC's.

Quad-seals, two sizes seen in the center of the above shot, are basically O-ring with the sealing portions at the center and outboard areas of the seal enlarged a bit. These are recommended for axial sealing, but, if well lubricated, do offer some usage in radial traveling shaft sealing jobs. I have almost exclusively replaced the cup-seal with this much cheaper and readily available quad-seal. I employ these seals in all my resin bodied pushrod seal units.

Lower right is your MK1 Mode0 nasty old O-ring. These are recommended for static sealing and limited use with axial traveling shafts, but the dirty little secrete is that they do find some limited use with radially running shafting if great care is taken to minimize the compression fit between rubber and shaft. Cheap, plentiful, and easy to find, O-ring are best used to make the watertight seal between bulkheads and Lexan tube.

One last beauty shot before I stuff this thing in its shipping packaging. OK, I've had my fun with it at the pool ... now, the customer can have it (Lord knows he's had to wait long enough for it!).

Ellie and I took u/w shots of the SEAWOLF while it was operating at the Lynnhaven Dive Center pool, using this waterproofed video camera-transmitter. I designed the WTC that protects the unit. The 2.4 gigga Hz Swann camera-transmitter and associated receiver is purchased from Radio Shack. Here's a site for you if your interested in reading and seeing more about this unit: http://www.rcgroups.com/

forums/showthread.php?t=339195 .

Attached to the end of a broomstick the unit is held underwater so that just the tip of the antenna projects into the air. The signal it sends out goes to the receiver, mounted on a video monitor-VHS recorder, where the images are stored on a cassette for later editing. Ellie sits in a chair pool side as she aims the camera at the subject, a small monitor, on her lap serves as a viewfinder, letting her frame the shot.

The stated range, in air, for the Swann system is three-hundred feet. I've tested that and got good signal in excess of three-hundred feet. Not bad for a little transmitter that only squirts out less than ten milliwatt's at the antenna! With a Yaggi or Patch type receiving antenna I imagine you could double the range, but then you be burdened with the need to 'aim' the receiver antenna at the transmitter's antenna. Why bother? Three hundred feet is more than good enough for r/c submarine!

To better illustrate how versatile these little Swann video camera-transmitters are, here is a shot of a permanently mounted camera-transmitter within the sail of this Bob Wallace 1/16 Japanese suicide submarine model kit. The scale cutout in the leading edge of the sail formed a perfect porthole for the camera lens. You can see the image taken by the camera on the little portable black & white monitor (same one Ellie used during the u/w SEAWOLF shoot at the Lynnhaven Dive Center pool). The camera output is color, by the way, and the resolution is 380 lines --equivalent to VHS quality. Not bad for such a tiny package!

The 1/16 Japanese suicide sub model in my son's above ground pool last summer. This model turned out to be a near perfect real-time video camera system platform. I sometimes operate the model with a set of virtual-goggles on: I drive the model as I observe from the submarines POV - very interesting stuff and sometimes a bit discerning ... once I got seasick as the model bobbed on the waves at Lake Trashmore. I actually puked...

... Neat!

The video camera-transmitter WTC, off the broomstick and rubber-banded to the deck of the SEAWOLF. We have some very good u/w video tape on record now, much of it taken from the models POV. As you can see, my video camera-transmitter WTC unit can be quickly moved from one model to another or used off-model to record the u/w action.

The following u/w shots were taken with a disposable u/w film camera -- they're so cheap now, about eight-bucks, that you would be foolish not to document your submerged model with one of them. As they do not have a flash, such cameras have to be used under bright sunlight and in clear water. Also, since these cameras are preloaded with 800 ASA color film, the resulting prints are a bit 'grainy.' But, using these cheap little cameras is safer than sticking your high-value digital camera in an enclosure and hoping it won't leak on you!