Improving the SubTech 1/60 ALBACORE phase-2 Kit, Part-3

A Report to the Cabal:

Some more work on the sail -- working two of them now, the original phase-1 and

the later phase-2 and on version.

I started and am almost finished with the phase-1, 2 and (possibly) 3 propeller
master and tool. And I've fit the horizontal stabilizer to the tail-cone, so I'm ready
to make intermediate tools for that item.

Work continues.

When working large projects, like the masters for this forty-inch long submarine, its convenient to have nearby a worktable set aside to be used only for plans lofting and documentation examination and reading -- it's such a drag to have to clean off the worktable to make room to spread out flat the working drawing and other reference documents. Shop efficiency goes down directly in proportion to the number of times you have to arrange things to make room for specific chores.

I like to work in an environment where I have tables dedicated to any one project: one for the actual model work, a sit-down station with moto-tools and hand tools at the ready. Another table to spread out, read and loft off document measurements, like you see above. And two stout tables mounting bandsaw, machine lathe, milling machine, sanding machine, and a drill press.

I'm talking dedicated work space here, boys and girls!

A Renshape sail master in the jaw of a Machinist's vice bolted to the X-Y slides of the milling machine. Here I'm using a big end-mill bit to dig out the interior of the sail master. Clamping pressure from the vice prevents me from cutting all the way through, so I cut from the top, flipped the work, then milled from the bottom of the master, leaving about a half-inch of material in the center of the piece. After these initial cuts on the milling machine I remove the sail, split it, and finished off the hollowing operation with files and sanding blocks.

Oop's! .... Removing the two tack-glued halves from one another did not go at all well!

Anyway ... after breaking the sail master into four pieces (two uninvited breaks, two planned breaks along the centerline of the master), I glued the pieces of each half back together with thin formula CA. Fortunately Renshape Pattern Maker's foam has a base chemistry to it, so the adhesive cures very quickly -- all I had to do was key the broken pieces back into alignment, run some glue onto the seams and capillary action got the adhesive wetted into the butt joints and set almost immediately. The fix only took minutes.

After repairing the damage by the splitting attempt, I tack glued the halves back together (lesson learned: don't use so much fuck'n CA when tack gluing!). The two halves temporarily in alignment again I drilled two 1/16" holes at the leading edge and another pair at the trailing edge. Taking the two sail halves apart again I installed four brass pins into one halve, these made perfectly registered connections to the other halves holes, permitting me to fit the sail halves together with no registration issues at all.

Here you see how the pins and holes work to register the two sail master halves together. There is enough friction here to permit the halves to hold themselves together tightly without assistance.

A single, vertically oriented sail top template, cut from aluminum sheet, is sandwiched between Renshape 40 halves. Building up the sail top master this way insures I have a true longitudinal datum line (the upper edge of the template) visible throughout the masters shaping. The large white plastic stencil was used to scribe in the outline onto the aluminum template.

The nearly completed sail top master that goes with the phase-1 sail master. As I began the rounding of the sides of the sail top master I drew in transverse pencil lines that indicated radius of curve and symmetry between sides. I also used a Molder's gauge to check symmetry.

The just assembled phase-1, 2, and 3 propeller (but the recent Palmer book suggests that they went to a larger diameter, slower turning, wheel for the phase3 version). Without the dunce-cap the propeller is used for phase-1, with the dunce-cap, the propeller will be used for phase-2 and possibly phase-3 ... I have to look into this more carefully ...

... Steve Reichmuth: call your office!

Man! I hope I don't have to build a special phase-3 propeller!

The phase-1, 2, and (possibly) 3 propeller is represented by this master. Here the cast metal blades have been pickled in acid to make the surface receptive to strong bonding of the soon to be applied primer coat. The propeller is sitting atop the blade assembly jig, a tool used to insure equal spacing and angle of the five cast white metal blades onto the Renshape 40 hub.

In foreground are two unused metal blades still connected to their sprues -- I always make extra blades when building up a propeller master ... you never know when you will screw something up, and spares at hand can save time.

When I built the master of the horizontal stabilizer I built in an eighth-inch longer root than called for in the plans -- this to insure that I had a slop factor built in as I later trued up the horizontal stabilizer master on the tail-cone master as I established the fit between the two.

This was done by supporting the tail-cone master off a mold board with lumps of clay making contact with the tail-cone mandrel. A surface gauge was used to insure an equal height at fore and aft points over the clay. A right-angle triangle was used to check that the trailing edge of the stern plane ran truly vertical in relation to the board. Initially it did not so I worked the root of the horizontal stabilizer with drum sander and files till the unit sat on the tail-cone with the trailing edge vertical.

The phase-4 tail-cone being used to work out the concave root of the horizontal stabilizer master. Here I've lifted the work off the tail-cone after running it over a conformal piece of sandpaper -- the sanding is done with the tail-cone off the two lumps of clay, otherwise the pressure applied during the sanding would mash the clay supports out of true.

This master of the tail-cone will be marked with locater punch-marks denoting where the X-tail control surfaces operating shafts will penetrate. It will then be used to create a hybrid tool: a firm hard-shell outer casing, or 'mother-mold' with a soft chewy center, made of RTV rubber, called the 'glove mold,' the whole affair constituting a production tool used to make phase-4 (and later versions) resin, hollow cast tail-cone model parts.