Submarine Kit, Part-6

A Report to the Cabal:

I got bogged down with some preliminary chores that had to be done before I could mount the stabilizers permanently onto the hull. Therefore, today is the day the stabilizers go on.

But, first, the stabilizers themselves had to be cleaned up with some filler and sanding. And I had to insure that the control surface linkages were free of binding and that I got significant rotation of all control surfaces -- successful completion of this chore vital before I could confidently commit to permanently mounting the stabilizers to the hull. Measure twice, cut once ... as they say.

So, yesterdays work: pedestrian, but vital.

Somehow I had neglected to file off the flash, sand, and pickle the two deck cleats. A job that should have been performed when I addressed the other metal items. Once pickled, the three cleats were rinsed thoroughly in water, dried, then primed and set aside with the other detail items that go with this kit.

I took the additional measure of drilling a one-sixteenth hole in the base of each (I did three, one as a spare) and fitting a short length of brass pin. The flukes of these fittings are prone to grabbing things and snagging, so it's inevitable that one of them, someday, is going to be pulled off the model, either through collision in the water or (more likely) as a consequence of a handling accident. Hence the spare cleat.

I installed the internal yokes for the stern planes and rudders then connected the control surfaces, without their stabilizers. The propeller shaft was also inserted. The exercise here was to determine if the control surfaces could be rotated their full thirty-five degrees without interference between them or with the centrally running propeller shaft. Indeed, I did encounter some rubbing of the two yokes. That problem was addressed by taking the yokes out and shaving off some metal where they made contact. After two attempts I achieved the non-binding condition sought.

The unique thing about the KAIRYU design is the use of a set of horizontal planes on or near the vehicles center of gravity. These can only exert a direct dynamic force, up or down, with little or no pitching component to the force they exert. Therefore, these planes are only used for depth control. Though looking very much like a set of 'wings', particularly so when surrounded by their stabilizers, these control surfaces are analogous to the sail planes employed on many of today's modern submarines -- control surfaces dedicated to depth keeping only.

The upper hull removed to show how the two internal yokes make up to the stern control surfaces. Each yoke is equipped with a bell-crank at the end of which is secured, through a 'Z' bend, a length of one-sixteenth-of-an-inch brass wire which serves as a pushrod. Eventually these pushrods will make up to the WTC stern plane and rudder pushrods. Note that the 'U' shaped yokes permit clearance for the centrally running propeller shaft.

Each control surface operating shaft is secured to its respective yoke via a small 440 set screw, you can make out the heads of those set-screws at the ends of each yoke.

This type linkage is pretty much what you would see in the mud-tank of just about any single-shafted submarine today I ran a single control surface operating shaft through the hull here only because the unsupported depth-control planes required it for this initial test. In the final arrangement each control surface shaft will terminate within its respective bell-crank, up against the hull. Fortunately for me the kits lower hull has the indexing lip which, here, serves as a bearing for the operating shaft.

Two pushrods will run aft (one from each bell-crank). They will join together aft of the WTC's motor bulkhead, at that point they will make up to a single WTC output pushrod -- that servo assigned to depth-control duties.

Rose playing with the control surfaces. Here you get an overview of their location and area. Plenty of rudder. The first KAIRYU I built and operated was a joy: turned on a dime and depth control was rock-steady.

Using the same alignment tool I made for the sail I checked the fit each stabilizer, and corrected each by conformal sanding until each sat perpendicular to the hull at the station assigned.

In order to be able to cant the control surface operating shafts into the base of the stabilizers (once they're installed onto the hull) I had to dig out the base of each stabilizer with a cone-shaped hole that would permit this. I found that the Caswell supplied cone diamond burr to be the perfect tool for achieving this. These are very robust grinders and the selection is broad enough to provide you a bit for just about any specialized job you will come across. Look over at, http://www. caswellplating.com/buffs/index.html This page covers some of the Caswell offered

abrasives and polishing tools.

After priming the stabilizers I gave each the great big hairy eyeball and laid down some filler at any pits, pinholes, and flash gaps found. Each stabilizer was later filed and sanded back to contour and given another coat of primer. The little pallet knifes on the left are excellent tools for applying small amounts of filler to specific areas of a model part requiring controlled, minute applications of either filler or putty. I got this set from Harbor Freight, http://www.harborfreight.com/

The sanded stabilizers and control surfaces were given a final light coat of well thinned primer -- now the stabilizers are ready for fitting and permanent attachment to the hull.

The propeller was treated to some selected putty work to fill flash depressions. Here I'm wet sanding everything with a medium grit Flexi-File stick. A dunking in acid, a freshwater rinse, a good drying, then primer, and the propeller will be ready for 'brass' paint.