A Skipjack in Ireland

[The Boattrainman]

Final shots of completed gratings.





As can be seen from this shot they are almost sanded flat to the hull.



There were over 70 pieces of Plasticard and 16 separate gratings but an enjoyable couple of evenings work.

The fact they are under the sub and will hardly ever by seen is.........well...........interesting.

The Boattrainman

[The Boattrainman]

Caswell Fittings etc, stuck in customs!!!!


The Boattrainman

[He Who Shall Not Be Named]

Caswell Fittings etc, stuck in customs!!!!


The Boattrainman

Ouch!,,,,,,

M

[The Boattrainman]

The Caswell parts arrived, well pleased, very good quality but won't use them all.

One area that has concerned me is that once the rear lower section is bonded to the upper hull, the access to the rear plane and rudder yokes (and their four small grommet screws) is four inches down a narrow tube. So I've decided to build an access hatch in the under the boat in the rear section, I'm hoping to make an invisible seal around this access hatch as I've done this before on other models.

The first job was to mark out the area to cut out and thankfully the holes in the lower hull for the strip of anodes are useful as a guide, as well as using masking tape for the cross hull marks. The dimension are clear in the pictures, these are crucial as they will keep the hole just aft of an internal brace piece inside the moulding.




I used a very narrow hobby saw and a metal 90 degree right angle to keep the angle of the cut to the slope of the hull, and the secret to getting a clean cut is to cut a ridge along the whole cut first, that way the saw will follow the weak point. I had to use a Dremel rotary tool with a thin cutting disc on the cuts from bow to stern.




The removed piece is then 'repaired' around the edges with 0.5mm Plasticard, a large piece is stuck on each side and then cut and sanded back to the shape of the edge.



The access hole has pieces of 1mm Plasticard glued to the edges up against that the internal molding and protruding 1mm into the hole to stop the hatch falling into the hull, plus four small pieces that will hold a cross piece (2 X 2mm Plasticard pieces glued on their edge). This cross piece is NOT glued in place, but will be removed once the hatch is open for access, a finger down the hull on the inside holds it in place when re-fitting the hatch.




The hatch is secured with a tiny self tapping screw, through to the crosspiece and then the hatch is sanded hard to fit the hull profile, a bit more work on sanding the edges and a decent paint job will render the joins invisible thanks to the 0.5mm Plasticard fillets on the edges. To hide the screw which has been countersunk, a small piece of Bluetack is put on the head and flattened. Once painted over hopefully it'll be invisible, but if emergency access is needed it can be peeled off to reveal the screw. It will have to be repainted if needed after that, in the meantime I have close access to the rear dive plane yokes and other parts at this tricky location.




I'm sure other builders may not want this hatch, but it's my experience that once you restrict access to some mechanical parts, they are the very ones that give trouble. Murphy's Law!

The Boattrainman

[He Who Shall Not Be Named]

The Caswell parts arrived, well pleased, very good quality but won't use them all.

One area that has concerned me is that once the rear lower section is bonded to the upper hull, the access to the rear plane and rudder yokes (and their four small grommet screws) is four inches down a narrow tube. So I've decided to build an access hatch in the under the boat in the rear section, I'm hoping to make an invisible seal around this access hatch as I've done this before on other models.

The first job was to mark out the area to cut out and thankfully the holes in the lower hull for the strip of anodes are useful as a guide, as well as using masking tape for the cross hull marks. The dimension are clear in the pictures, these are crucial as they will keep the hole just aft of an internal brace piece inside the moulding.

[ATTACH=CONFIG]n113598[/ATTACH] [ATTACH=CONFIG]n113599[/ATTACH] [ATTACH=CONFIG]n113600[/ATTACH]


I used a very narrow hobby saw and a metal 90 degree right angle to keep the angle of the cut to the slope of the hull, and the secret to getting a clean cut is to cut a ridge along the whole cut first, that way the saw will follow the weak point. I had to use a Dremel rotary tool with a thin cutting disc on the cuts from bow to stern.

[ATTACH=CONFIG]n113601[/ATTACH] [ATTACH=CONFIG]n113602[/ATTACH]


The removed piece is then 'repaired' around the edges with 0.5mm Plasticard, a large piece is stuck on each side and then cut and sanded back to the shape of the edge.
[ATTACH=CONFIG]n113603[/ATTACH] [ATTACH=CONFIG]n113604[/ATTACH]


The access hole has pieces of 1mm Plasticard glued to the edges up against that the internal molding and protruding 1mm into the hole to stop the hatch falling into the hull, plus four small pieces that will hold a cross piece (2 X 2mm Plasticard pieces glued on their edge). This cross piece is NOT glued in place, but will be removed once the hatch is open for access, a finger down the hull on the inside holds it in place when re-fitting the hatch.

[ATTACH=CONFIG]n113605[/ATTACH] [ATTACH=CONFIG]n113606[/ATTACH]


The hatch is secured with a tiny self tapping screw, through to the crosspiece and then the hatch is sanded hard to fit the hull profile, a bit more work on sanding the edges and a decent paint job will render the joins invisible thanks to the 0.5mm Plasticard fillets on the edges. To hide the screw which has been countersunk, a small piece of Bluetack is put on the head and flattened. Once painted over hopefully it'll be invisible, but if emergency access is needed it can be peeled off to reveal the screw. It will have to be repainted if needed after that, in the meantime I have close access to the rear dive plane yokes and other parts at this tricky location.

[ATTACH=CONFIG]n113607[/ATTACH]


I'm sure other builders may not want this hatch, but it's my experience that once you restrict access to some mechanical parts, they are the very ones that give trouble. Murphy's Law!

The Boattrainman

Excellent photography and narrative. You're a thoughtful and skilled craftsman, sir.

But, the stern hatch is overkill -- every mechanical device is accessible (removable) If you bond the upper stern piece to the lower hull as I described.



M

[The Boattrainman]

Here is another 'invisible' join on my 1/32 scale Ben Ain Steam Coaster.




The rudder attachment is hidden under a false deck plate, made of aluminium the same thickness and size as the other plates in Plasticard, the extra weight of the metal holding it down.




I've a picture somewhere of my U203 (Robbe kit, Engel PistonTank, now sold), with an almost 'invisible' join around the whole rear hull, struggling to find it.

The Boattrainman

[The Boattrainman]

I totally agree, it's overkill.

Sorry, I'm a bit OCD on access, but prefer to have the extra hatch, my digits are not as agile as they once were.......!

Thanks for the compliment.

The Boattrainman

[The Boattrainman]

Here is the access the extra hatch affords.



I can work on the grommet screws in the yokes directly, I agree with David there is direct access down the hull also, but even on a visual level it's helpful.


I'm using a clevis and threaded rod system as linkages, the clevis is attached to the yokes before inserting in the hull and the threaded rod inserted down the hull into the clevis, then tightened to assist lining up the rudder and dive planes and then unscrewed back a little. A piece of the rudder yoke has been filed away to get good clearance of the dive plane yoke clevis.




It's a neat little control system, hats off to the designer, and I have to say given they are white metal parts which usually require cleaning up, they were useable right out of the package.


The Boattrainman

[The Boattrainman]

There are some gaps in the indexing seam uniting both halves of the hull.




The hull seam could do with extra bracing, so at these points 24mm wide pieces of 1mm Plasticard have been glued to form strengtheners.

3

The eight indexing pins on the kit have been cut down by 3/6mm, the ones nearest the bow cut the lowest, and their tips rounded off with sandpaper, so they will slide easily into the opposing pin holes.

They look flimsy, but if polystyrene cement is used they will be as strong as the hull. This is the advantage of the kit material, if the hull was made of GRP (which most R/C Boat Kits are), epoxy or CA would be needed and it wouldn't be as strong because the hull is effectively melted to the Plasticard strips.

The Boattrainman

[The Boattrainman]

I've a question for anyone with this Skipjack.

I noticed Greenman and others not being overly impressed with the sail planes. This is a small model (in some regards, bigger in other), it's not going to take much to get it diving once the ballast system is sorted. I'm getting the impression that the sail planes are not necessary for operation.

I'm going with electronic linkage of the aft and sail planes (or mechanical, will have to wait for more parts to arrive), and I'll probably construct the sail planes as operational anyway.

Anyone got any thoughts?

Rob

[He Who Shall Not Be Named]

I've a question for anyone with this Skipjack.

I noticed Greenman and others not being overly impressed with the sail planes. This is a small model (in some regards, bigger in other), it's not going to take much to get it diving once the ballast system is sorted. I'm getting the impression that the sail planes are not necessary for operation.

I'm going with electronic linkage of the aft and sail planes (or mechanical, will have to wait for more parts to arrive), and I'll probably construct the sail planes as operational anyway.

Anyone got any thoughts?

Rob

Yes.

The sail planes are practical and make the boat easier to drive underwater.

M

[trout]

When I first launched my Skipjack, I had an issue with my sail plane's linkages. I put the planes with a slight downward and then with them at level. Both ways worked. The level planes better than the slightly angled down. This boat is a rocket underwater and the slightly downward angle made the boat dive as I went faster (as it should). With level planes, I was able to adjust depth with the leveler on the aft planes. However, once I got the linkages connected, it was even more sweet to drive. I had better control of the sub (easier to run straight and level). This allowed the leveler to do what it was meant for, keeping the boat level and I could used the sail planes to adjust the depth. So hopefully this keeps HWSNBN from getting grease and smiling at me.

[The Boattrainman]

Roger that guys, points noted.

So to the task of making a working tail light, first up was to draw out on paper the outline of the Caswell part, to get the shaft angle correct.




A piece if brass tube the same diameter of the Caswell part is cut to length using a tube cutting tool, the wires for the light will go down this tube, then down the internal rudder yoke. A notch has been filed at the top of circle where the wires exit so they can be bent out of the way of the prop shaft. A semi-circular hole is filed on both kit pieces where the brass tube will enter in line with the drawing.




1mm Plasticard supports to the shape of the internal space are glued to both sides of the Revell kit parts, up against the square moulding which is used as a guide to the height of the brass tube. Another strip of Plasticard is stuck on these pieces in line with the hole for the brass shaft which is lightly Superglued (CA) in place.




A 3mm hole is filed at the top of the rudder to take the LED, a semicircle on both kit halves so when they unite it's a round hole. Two small scraps of 1mm Plasticard are stuck to support the light and the the LED is glued to one of these.




To the next post.

[The Boattrainman]

The wires are pulled up through the brass tube then soldered to the resistor and LED, and two pieces of scrap metal plate are used as a heat sink for the resistor and glued to each half.





All the internal parts are flooded with epoxy including around the brass tube. The sides are united and the light tested, if you notice it's not a pure white LED that's because the pure white in most LEDs is not realistic, most white lights are softer and I've used a soft yellow instead, the white is just too intense.





When the rudder is installed the wires are fed down into the yoke before the shaft is dropped in and pulled out into the hull.

No wires to be seen!

[greenman407]

Nice Job. Since I bought the fittings kit, which comes with solid rudders, I never even thought about using the kit supplied rudders. It does make installation of lights easier. Good Call.