A Skipjack in Ireland

[The Boattrainman]

The sail has had all the holes opened to take the Photoetched parts. I'm just using the larger PE parts as the smaller ones are tiny.




The sail with the PE parts attached in the pre-drilled holes which have a backing of 0.5mm Plasticard and the hole filled with 1mm card and then the PE glued into the recess.




To be honest, apart from the vents on both sail sides which match my hull gratings nicely, I'm not sure the PE parts will add that much to a R/C model given the viewing distance, perhaps a super-detailed static model will benefit more, given this detail work took over a week of drilling, sanding and fettling.

That said, there are superb parts for the port/starboard sail lights and the radar on the PE fret which could not be produced any other way.

The Boattrainman

[The Boattrainman]

A final test of all the running lights is done, the wiring is led through the various guides and the sail sides and top united. An old model train controller is used to replicate the 12V running battery.





I'm giving some consideration to the mast light being a 'nano' LED, but I'm quite happy with the lights at this stage.




Time for some Primer, I find this is the only way to identify and rectify surface blemishes, of which there already many.

The Boattrainman

[trout]

Well done lighting!

[The Boattrainman]

So some good and bad news with the first of many Primer coats, which will be done with acrylic spray cans (Humbrol range).




The main seams have come out quite well and will need just a small amount of work, there's a seam running top to bottom here, nearly invisible.




The Photoetched hatches and ballast vents add nicely to the main deck.




The scratchbuilt inlet gratings look reasonable now they have blended in.




However, there is a serious problem with the nose! As well as the obvious line where the two halves meet which can be filled, there is a dip along this seam resulting in the rounded shape having a flat in it around the entire nose, plus (to my eyes) the nose is slightly an odd shape, with the most forward part having a slight bulge outwards again spoiling the teardrop shape. It's not a biggy, but it will need some work to get it properly 'rounded', but it's the only flaw in what has been an excellent kit so far.

As for the flat meeting of the two halves, I can't see any solution other than some serious filling/sanding.



If you enlarge the picture up a bit, you can clearly see a flat spot to the left of the torpedo doors at the seam.

The Boattrainman

[The Boattrainman]

To try to solve the flat line around the seam, I've stuck a double thickness line of masking tape either side of the seam one on top of the other, and filled the gap with filler. When the tapes are removed this leaves a ridge of filler.





This ridge is sanded into the hull but the centre is left alone reinstating the curve, plus I have hard sanded the top of the nose back to get the shape totally symmetrical.




Because I hard sanded the nose, I lost definition of the scribed lines for the torpedo doors, I had to re-scribe the centre ones (they are a bit rough in the photo, I'll fine sand etc. later).




The nose (in my humble opinion) is still not 'perfect' in terms of shape, but I can live with it now.

The Boattrainman

[The Boattrainman]

The main hull is now blemish free, the access door and other parts will now be 'primed'.




There was a lot of work to fair the large vents into the hull.




The main hull is now blemish free, it took three evenings work.




The Boattrainman

[The Boattrainman]

Occasionally you come across a blemish in a horrendous location. This nick around 2mm wide was in one of the rear dive planes, filler won't work here as the insertion of the dive plane axle will eventually destroy such a repair.




To fix it, the nick was filed out to a roughly square shape and using a scrap metal bar inserted in the axle hole as a backing, a small fillet of Plasticard loaded with thick Superglue is inserted into the enlarged hole. The metal bar is pulled down the hole before the glue sets, leaving the fillet intact.




The fillet is carefully cut back, and before final sanding a small amount of very thin Superglue spread around it and then sanded back to the shape of the plane.




Once primed, the repair is invisible.

The Boattrainman

[The Boattrainman]

There is a great story about Vic Green, one of the greatest professional Model Locomotive builders ever, his 1/35 Scale British locos go for many tens of thousands of pounds and were only available to 'rich' clients with large cheque books.

When questioned about the high cost of each item, he explained that as well as the hours needed to construct the models from scratch (which if billed by the hour would mean the items would be even beyond the well resourced), he rejected about two-thirds of his work as not up to standard, I think in his career he built under 50 locomotives. One of his masterworks is below.




While I'm not in Vic's lofty league, I've decided the sail is just not good enough. The difference between the vents/access hatches using the Photoetched parts and original Revell scribed ones are too different, leading to an inconsistent look. One of the key aspects of any model is that the overall model must look like similar techniques were used for the end result, and as it stands this is not the case with my sail.




So this will have to go in the bin.

The Boattrainman

[The Boattrainman]

Here is the second attempt at the Caswell sail plane linkage/yoke, a process I should have undertaken the first time.

Squares and a ruler are used to measure the distance between the axle centres which is 24mm for a tight fit of the teeth in the units. The distance is drawn on to two 12mm wide pieces of 0.5mm Plasticard.





Once drilled for both the sail plane arms and the yoke axle the parts have two square pieces of 2mm card glued to the bottom of the new fitting where the yoke axle will fit. It is opened out to the axle diameter and then a trial fit of the parts is undertaken





This little mechanism sets the distance between yoke and sailplane cog, no matter how you set them they will always be at the correct distance and perfectly interlocked.





The new parts are stuck to each side of the new sail planes I acquired from another kit, the straight lines help to keep it all in line. The sail plane hole is made to align with the top hole of the new fitting, if you have the Caswell resin bushes they can be pushed into the hole from the outside, mine are gone on version one, but it doesn't matter the Plasticard is strong enough to act as an axle bearer.

The Boattrainman

[The Boattrainman]

The throw extender is shortened and a servo arm connector is attached to further move the attachment point away from centre. A number of L-shaped pieces of Plasticard are cut to 10mm width and a hole to take the 'snake' pushrod drilled in each.





The 'snake' is fed through the holes and the inner sleeve inserted in the pushrod connector, I've cut away sections of the inner hull bracing to allow the snake pass plus moved it further toport to connect with the lever mechanism I made to attach to this pushrod and the sail plane servo pushrod exiting the Subdriver.




The Boattrainman

[The Boattrainman]

The new sail means I can re-visit the wiring, so I've gone for something different to last time, just one + and one - existing the sail.




The side lights get a plastic surround again.




They are filled with epoxy to completely enclose the wiring and resistors.




A bit neater than six wires to deal with, I'll close the sail later but work out a wiring route in the main hull next.

[The Boattrainman]

The new sail sides are united and primed.




The sail top is not glued on yet, I want to see the snorkel operating correctly when installed, I understand there is a Mark 2 Snorkel with the 3.5''Subdriver.




There is still plenty of minor filling and sanding to do.




On to the wiring route inside the hull.

The Boattrainman

[He Who Shall Not Be Named]

Your comment as to there being a, ‘MK-2 Snorkel’ provided with the 3.5 SD may originate with an earlier post where I described the ‘horizontal’ type snorkel mechanism I developed for use in the smaller 1/96 SKIPJACK kits I produce. As that sized sail is too narrow to provide for a proper float I was compelled to go with this arrangement – that took advantage of the wider base of the sail. However, this mechanism is not to be confused with the ‘vertical’ snorkel mechanism employed (and provide with the 3.5 SD) by the 1/72 SKIPJACK.






Just a little refresher on how the SemiASpirated ballast sub-system works. Air to blow the ballast tank is either scavenged out of the SD’s air-spaces or from atmosphere from the open snorkel head-valve. The examples here show the safety float-valve with the external plumbing, the 3.5’s unit is housed within the after dry space and has no external plumbing.





Typical of the ‘vertical’ type snorkel mechanism provided with the 3.5 SD. It fits comfortably within the 1/72 SKIPJACK sail.



Break-down of a typical ‘vertical’ type snorkel mechanism – there are slight differences for different scales and types of r/c submarine sails these things have to fit into.

[The Boattrainman]

Thanks David for the info on the snorkel assembly, much appreciated

To lead the sail lights wiring to the connection point at the rear of the sub, I've made some 3cm long wire guides from 7mm square Plasticard, each with three 4mm holes drilled so air and water won't get trapped in them.




They are glued to the hull on the opposite side from the sail plane 'snake', and a loop of wire will be left so the sail can be lifted off for maintenance.




The wiring will go to the rear of the sub to unite with the rear light wiring.




The Boattrainman

[Tugfan]

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