Cartoon scale working paper model of S503 Pietro Calvi

[zhuravlik]

Hi lads,
I proceeded for stern cut with aid of some masking tape and razor saw: it came out very clean.
Got some issues with foam removing. Removed the most of it mechanically and used some nitro on the bow: somehow it softened (poisoned?) the laminated glass.
Took a night on the radiator and some buffed epoxy to restore hull strenght.
Speaking about the inner components, I've almost finished the piston tank unit wich now operates super smoothly thanks to the oring piston. Devised a switch assembly using some pcb pieces and a couple of metal brushes. Propulsion gearbox was drilled to not trap some air and rudder shaft and driving magnet have been mated.

[zhuravlik]

And obviously switch assembly doesn't work because the contact must be normally closed, not normally open...
Shamefully back to the drawing board, though my micro-switch are a tad big for this project, maybe I can find two smd mounted switches in an old mobile phone.

[zhuravlik]

Hi lads,
I've decided to go without endpoint circuit cause i could not see any ill effects. Also had to change motor gearbox; the sub was way too slow.
Built a lead keel by hammering a lead rod to the right dimensions, gluing on the bottom of the sub and creating a metallic putty fillet around it.
I'm very happy about magnetic actuated rudder: light, easy and all internal and it work like a charm.

https://www.youtube.com/watch?v=wN5m56P3zeM&feature=youtu.be

Woks left to do: build a sail, install the bow dive planes, scribe some details on deck and paint the darn thing.

[zhuravlik]

I've been working hard at this boat to dust off a set of skills after boat servicing season. They will be needed during this winter.
I like this subject and I really hope to find some more infos about it, enought to model it in 1/72 scale.
In the meanwhile I've built the sail using some thin plasticard and it weights 1gr unpainted, used some thin fishing line for handrail. Next came those odd fairings on the stern: they are made using renshape drafted with cutter and glued on to be shaped with sandpaper and patience. A raid to the scrap box produced some usable deck fittings. After balance and immersion tests, the model has been painted with flat black below design waterline and RAL 7026 above, all sealed with tranparent flat acrylic. I had to cut off some 2mm to the rudder's trailing edge in order to help that poor magnetic actuator and this worked. I've balanced the boat with a 400mAh 1s Lipo and this should give me gobs of autonomy. Expect a launch in short order and watch this:)

https://www.youtube.com/watch?v=bpNhZGTJrtc&feature=youtu.be

Best regards,

Francesco

P.S. I've eyed another oddball to model: KNM Kya (ex U926) as converted in 1959 with a new Walter type sail for trials and I've submitted a letter To Director of the Royal Norwegian Navy Museum begging for a few photos.

[He Who Shall Not Be Named]

You, sir, are a MACHINE!!!

m

[zhuravlik]

Thank you sir, I hope to become a modeler like you, Manfred and everyone contributes to this wonder-forum.
I've painted the deck sonar dome and added water line decals, still have to paint limber holes, that curved slot and sail windows, planning to use some paper stencils as masking tape cant be cutted sharp enough.
But the main piece of news is that I've found a photo of Kya!!! It was sufficient to search for it in norwegian (K-klasse undervannsbåt). This, coupled with the drawing at page 161 of Eberhard Rössler's Uboat is sufficient to make a 1/144 model of it! But this is another story, expect a new building thread soon...

[zhuravlik]

Ah, It's not a photo of Kya, it's the ex HMS Viking. Those front dive planes are a dead giveaway...

http://www.sjomilitaere-korps.org/u-klassen

[zhuravlik]

Hi lads,
Finally had some time to throughtfully test Pietro Calvi at Vasca Malaspina.
First test showed lack of range and a tendency to dive abruptly under full power (remember: no proportional control here and no pitch control as well).
Once at home I found that radio pcb was touching one of the actuator connections: some insulating tape took care of this and the range issue is solved.
Stern planes were responsible of abrupt diving because i've glued them at 2° diving. Reglued to zero incidence.
Today I've tested those mods and I'm rather pleased about results. For being a 3 channels bang bang you can control it with decent accuracy.
Please see video:

https://www.youtube.com/watch?v=ns6hF548MPo

[He Who Shall Not Be Named]

Hi lads,
Finally had some time to throughtfully test Pietro Calvi at Vasca Malaspina.
First test showed lack of range and a tendency to dive abruptly under full power (remember: no proportional control here and no pitch control as well).
Once at home I found that radio pcb was touching one of the actuator connections: some insulating tape took care of this and the range issue is solved.
Stern planes were responsible of abrupt diving because i've glued them at 2° diving. Reglued to zero incidence.
Today I've tested those mods and I'm rather pleased about results. For being a 3 channels bang bang you can control it with decent accuracy.
Please see video:
https://www.youtube.com/watch?v=ns6hF548MPo

Depth control via throttle. Slick! And a demonstration of fine craftsmanship throughout this WIP. Very, very nice work, sir.

M

[Von Hilde]

This build was yet another inspirational experience. A paper sub is what got me started fooling around with model subs. I started building a 1/48 scale Fletcher class destroyer hull from wood frame and construction paper. Intent on making fiberglass negative mold, to pop out a couple layed up glass hulls. By the time I had finished the paper hull and sealed the exterior with epoxy, I decided just to seal the inside with the epoxy as well. I really only needed on hull so I just kept it like that. That WIP had been going on for several years off and on. My son, who is active duty USN, came home on leave a few years ago and suggested to have a U boat in that scale to go with the Destroyer, so I built a paper and sticks type VII, no plans, just pictures and a few drawings. Display only. Just to see if I could build a submarine. Submarines wernt my favorite type of model, back then. Too much time having to deal with the real ones while I was in the Navy. Airplanes and armor were my modeling endevors, when I was a kid in the early 50s. A "West System" type of construction may be the most practicle way to scratch build a one off hull. A couple decks of plastic playing cards, and a quart of resin and some wood and wire. Skills not included, "Dont try this at home" disclamer, of course. Man! I Love this place.

[zhuravlik]

I'm still surprised it took only a few hours to make that card model, very useful when you're trying to nail a shape. It helped a lot indeed!

To fight back frustration from kya's woes, I've started to refit S503.
Started to put on those bow dive planes, a simple adjust and tack in place job done with some 1mm plasticard, 1mm shaft and tube. Then the plan called for a prop swap. Originally i mounted a bronze MoVo prop, wich weights a whopping 1g while the new prop weighs 0,1g and it features less pitch too. With a lighter prop i can get rid of that piece of foam i had to add under the stern deck. Added a bit more area to the rudder by gluing tiny plastic strips both at the leading edge and trailing, much better turning radius! Drilled those pesky little limber holes and filed them till satisfied. Tried to represent the superstructure-hull slot by slightly scribing it, not really happy with this..Then painted lower hull with tamiya nato black and upper one with a heavily sun faded RAL 7026. Having worked at La Spezia for several years I can tell you that this colour fades to a light indigo when exposed to the mediterranean sun. Here are based some old Sauro class SSK's.
I'm working to make some new decals, incuding the sail number and I should really do some weathering.

[zhuravlik]

Decided to do sail number with a stencil rather than printing it on waterslide paper. I've used some printed tracing paper. Came out pretty wel, i think.

[zhuravlik]

Decided to do a little rhinoplasty: pointy bow, straight cutwater, more pronounced sonar bulb and scribed torpedo doors. Got the casing slot scribed and painted.
LSV Kokanee was refurbished too and got an action cam on her bow.

[zhuravlik]

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[trout]

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