The Ship Model Forum

Hi all

This project has stalled for ages. I guess I'm not used to how complicated the internals actually are on these things. I will return to it, as I very much want to see the finished model on the water. Life can get pretty busy and other work and hobbies have got in the way, including an addiction to pre war sports cars! I have retained my own finished model of C1 but for all those who showed interest please note the hull moulds, and fittings moulds, plans and production rights have been passed on to Adam Slater at Mountfleet Models UK. If yo want your own C Class at 1/48th scale, talk to him.

Thanks to all those contributors who helped with advice. I will eventually post finished on the water photos, promise.

LOL. Yeah, those things are funnier if you're made to work for it. Dear God, tell me you didn't tell her what you were laughing at.

Anyway ...

With your seal hydrostatic force will eventually shove the grease and water into the dry space -- stuffing tubes went out with the buggy-whip. How about some of my seals? Suitable for 1/16" or 1/8" pushrod diameters. If so, send me your address and I'll fix you up. dmeriman@aol.com

Those seals have a body diameter of 1/4" and the length is about 1/2". They'll last forever and only require the occasional drop of silicon oil on the pushrod.

[url=http://www.servimg.com/view/18504755/76][img]http://i19.servimg.com/u/f19/18/50/47/55/000_yg10.jpg[/img][/url]

[url=http://www.servimg.com/view/18504755/83][img]http://i19.servimg.com/u/f19/18/50/47/55/dscn0112.jpg[/img][/url]

[url=http://www.servimg.com/view/18504755/82][img]http://i19.servimg.com/u/f19/18/50/47/55/05910.jpg[/img][/url]

David

Hi David

Thanks for all the help. Couldn't figure out your abbreviation (R.T.F.M :scratch: ). It was only later that night that the penny dropped and I sat up in bed and laughed out loud. My wife thought I had gone slightly off my head!

Hi all

The WTC end bungs needed to be fitted with seals for the rudder and diving plane connecting rods. These seals or waterproof glands were made up from thin walled aluminium tube. Aluminium plugs were turned up for each end of each tube. These plugs were drilled to take the rods. After push fitting one end plug the tubes were one third filled with RTV silicon rubber, the stainless steel connecting rod previously had been sprayed with release agent. When the silicon rubber had set the remainder of the tube was packed with waterproof grease before push fitting the other end plug.
I’m pretty confident that this will provide a watertight seal yet not restrict the movement of the connecting rod.

[quote="PICKETBOAT"]David

Guess what. I went and looked carefully at the instructions for the Auto Levelling device. Yes it does say connect it to the aft diving planes! I would have checked when I came to the installation, but having only given the paperwork a cursory glance I had got it wrong in my head. :doh_1:
The pictures show this little AL5 unit (which I am assured will cure any tendency towards porpoising) supplies by Subtech. The other picture shown the little 1amp speed controller (stripped of its case to save space) supplied by Action Electronics and destined to control the main motor.
I really rate these little speed controllers. Very compact, durable and have fantastic slow speed control.[/quote]

Hey, only the weak read the instructions! (anyway, not till you botch things up and read them only as the last resort). In Torpedoman school the first thing they taught us was, R.T.F.M. Applies here too.

The SubTech unit is a nice product. You'll do fine with it, sir.

David

David

Guess what. I went and looked carefully at the instructions for the Auto Levelling device. Yes it does say connect it to the aft diving planes! I would have checked when I came to the installation, but having only given the paperwork a cursory glance I had got it wrong in my head. :doh_1:
The pictures show this little AL5 unit (which I am assured will cure any tendency towards porpoising) supplies by Subtech. The other picture shown the little 1amp speed controller (stripped of its case to save space) supplied by Action Electronics and destined to control the main motor.
I really rate these little speed controllers. Very compact, durable and have fantastic slow speed control.

[quote="PICKETBOAT"]David

Many thanks for the knowledgeable hint.

Looking at the model I did think it should be connected to the stern planes, but I'm sure the stability unit instructions said connect to the bow? The bow planes are slightly larger but are obviously not in the prop thrust. I will be relying on "dynamic diving" to get the last bit of the submarine underwater so the main motor will be running pretty much all the time she is submerged. I will go with your suggestion (you have far more experience on this than me).

Again many thanks.[/quote]

I may be mistaken as to what you meant by 'automatic stability control unit' -- I assume this is an angle-keeper, not a depth-keeper. They work on different principles:

The angle-keeper senses the gravity line, using that as the sensors reference plane. The angle-keeper circuit directs the servo to work the horizontal control surface(s) to maintain the boats longitudinal center line perpendicular with the gravity line. The angle-keeper is best employed to tend the stern planes as they tend to have the greater effect on the boats pitch than bow or sail planes -- hence the use of the stern planes as the force element of the control loop for control of boat pitch angle.

However, a depth-keeper senses the pressure of the surrounding water; water pressure a direct function of depth. The depth-keeper works those horizontal control surfaces best suited to effect a vertical force to the submarine -- typically bow or sail planes.

An r/c submarine absolutely requires the use of an angle-keeper or you'll porpoise all over the place -- no fun at all! However, the depth-keeper is a lazy-mans, show-off luxury (why not just hire a kid to drive your sub?)

[url=http://www.servimg.com/view/18504755/1039][img]http://i68.servimg.com/u/f68/18/50/47/55/dscf3510.jpg[/img][/url]

This show's the typical angle-keeper size -- this unit the excellent KMC ADF-2 (combined angle-keeper and fail-safe) device as installed in one of my smaller WTC's. These things used to be big, klunky things as the next shot illustrates

[url=http://www.servimg.com/view/18504755/1036][img]http://i68.servimg.com/u/f68/18/50/47/55/dscn0111.jpg[/img][/url]

The ugly fellow atop is a modified helicopter rate-gyro converted to a gravity sensor. The solid state units below it employed liquid based sensors -- this is old-school stuff used in a time when the earths crust was still warm. Fortunately today'sangle-keepers are small enough to work in boats of just about any size.

[url=http://www.servimg.com/view/18504755/1037][img]http://i68.servimg.com/u/f68/18/50/47/55/dscn0112.jpg[/img][/url]

The recommended ADF2 pictured below. Again: these are angle-keepers. They not only automatically tend the stern planes, they also allow you in the control loop as well. This device is a MUST HAVE aboard your r/c submarine.

So, all that school-housing out of the way: what 'automatic stability control unit' are we using here?

David

David

Many thanks for the knowledgeable hint.

Looking at the model I did think it should be connected to the stern planes, but I'm sure the stability unit instructions said connect to the bow? The bow planes are slightly larger but are obviously not in the prop thrust. I will be relying on "dynamic diving" to get the last bit of the submarine underwater so the main motor will be running pretty much all the time she is submerged. I will go with your suggestion (you have far more experience on this than me).

Again many thanks.

[quote="PICKETBOAT"]Hi Phil and Mick and anyone else.

Thanks for following and for the encouraging noises.

With the external detail just about complete, and the hull fitted out internally, the next task is to return to the WTC (water tight compartment) and install and test the equipment that will hopefully make the model function.

Just to refresh everyone's memory (including me) here is a diagrammatic sketch of how the actual diving system will function. I think the correct description is a "vented semi dynamic system". There will be no pressurized tanks and no pressure build up in the WTC

This means that the ballast tank when filled will (should) take the submarine down from surface running (waterline) to a point where just the top of the conning tower remains above water level. The vessel will therefore retain a slight positive buoyancy. This will be the safety margin. Forward motion and moving the diving planes to dive will hopefully submerge the vessel. Underwater stability will then be controlled by an automatic stability control unit connected to the forward diving plane servo.[/quote]

Put that angle-keeper on the stern planes.

David

Phil

Sorry forgot to say, nice locomotive. I love O gauge rail layouts. I love the almost realistic noise they make clunking over the points. Sadly lack of space and time here rule out owning one but if I did go for model rail that's what I would go for. It would of course have to be a British layout with some nice old rolling stock from about 1890.

Hi Phil and Mick and anyone else.

Thanks for following and for the encouraging noises.

With the external detail just about complete, and the hull fitted out internally, the next task is to return to the WTC (water tight compartment) and install and test the equipment that will hopefully make the model function.

Just to refresh everyone's memory (including me) here is a diagrammatic sketch of how the actual diving system will function. I think the correct description is a "vented semi dynamic system". There will be no pressurized tanks and no pressure build up in the WTC

This means that the ballast tank when filled will (should) take the submarine down from surface running (waterline) to a point where just the top of the conning tower remains above water level. The vessel will therefore retain a slight positive buoyancy. This will be the safety margin. Forward motion and moving the diving planes to dive will hopefully submerge the vessel. Underwater stability will then be controlled by an automatic stability control unit connected to the forward diving plane servo.

Congratulations on a well executed project!

I love the realistic overall appearance you achieved.

Glad to hear the masking tape worked well, will keep this noted somewhere.

Cheers,

Mick

I have never used stick-ons that had a surround material. All I have used are the type with individual peel-off letters and numbers on a wax paper/plastic backing.

I first came up with this idea in desperation on a model railroad project. No one made decals for the Willamette and Pacific short line in O scale. I needed a particular "Condensed Railroad Gothic" lettering in silver, and all I could find was adhesive lettering and decals in every color of the rainbow except silver.

So I painted the side of the engine silver, applied the stick-ons and then sprayed over with black. After the paint had dried 24 hours I used masking tape to lift off the stick-ons. You can see the results in the picture (although very poor resolution to meet the forum restrictions). The "WILLAMETTE & PACIFIC" and "1801" letters were done this way. It worked especially well, with the "A" in "WILLAMETTE" flowing nicely over the contours of the vent. The letters are essentially zero thickness - just as if they had been painted on with stencils (except the paint doesn't flow under the edges of the stick-ons). And there is none of the shiny clear background you can get with decals.

I also did the "1801" numbers on the end lights this way - applied stick-ons to the clear plastic lens, sprayed over with black and then removed the stick-ons to get lighted numbers.

When I get around to building my 1:96 USS Oklahoma City CLG-5 model I'll try to find the appropriate stick-ons for the stern lettering and hull numbers. This technique will work nicely over uneven surfaces such as hull plating edges.

Phil

Thanks guys.

First. The vinyl letters/numbers (from BECC) are good, but yes you are right, only suitable for larger scale models as they do have a "thickness" even if it is only a small one. The adhesive has some sort of cure time. They are re positionable and removable for about 24 hours then it gets more difficult. The instructions say no need to varnish over them, but as all my models are "working and wet" I tend to spray the model with a matt or satin varnish to protect them. This seals the vinyl numbers in and makes the edges merge, disguising any thickness (to a certain extent). Sticking each number temporarily on the end of a metal pin means you can hold them while the upper surface is sprayed to the desired colour before they are stuck in place. [b]I never thought of using them as a mask. That is an inspired idea. Just what these forums are all about. Pointing out the obvious which is staring you in the face but you cant see it.
[/b] :thumbs_up_1:

Phil.
Have you ever tried using the waste cut outs from the vinyl lettering sheet as stencils to spray through? A sort of reverse of your idea. I might try it as an experiment, and try your method too.

David.
The RN WW1 experiments, towing C class subs behind Q ships (sailing trawlers I think) were an unmitigated disaster. I think an attempt at trying to re enact it using RC models would end with me wading into the lake with my trousers rolled up and spending the rest of the afternoon disentangling both models from the tow line. Seriously it might just work but would require a good helmsman on both models, excellent coordination and a total lack of other vessels getting in the way. The first hurdle to cross is getting C1 to perform reliably on (and under) water.

Nice build!

I haven't used your vinyl self stick numbers or letters so I don't know how well they hold up in water. Your model is pretty large scale so the thickness of the adhesive letters won't be objectionable.

I have used adhesive letters and numbers, but only as "stencils." I paint the background the desired number/letter color. After the paint dries thoroughly I apply the adhesive letters/numbers. Then I paint over them with the desired surround color. After that paint dries I peel off the letters. There is no danger of the letters cracking or peeling off sometime in the future, and the resulting figures are only as thick as a coat of paint.

Phil

Quite the spiffy-looking pigboat you've got there, PIGBOAT! :D :wave_1: :thumbs_up_1:

A stunningly good looking display piece, sir. And a very, very complicated build -- nothing about this project was easy. Can't wait to see this beast in the water.

You know you're going to have to tow this thing, submerged, behind a period freighter type.

David

Hi all


The waterline was drawn in by mounting a fine pencil firmly on a suitable block of wood, cut to the correct height. With the model (on its stand) sitting on a smooth flat surface, like a kitchen work surface, the pencil was gently moved past the model touching the pencil tip against the hull in a series of fine dashes. I then masked up to this line with Tamiya 6mm masking tape. This is the first time I have used this stuff and it is very good. Never mind the expense when you get this far into a project! No visible bleed under the edge after spraying matt enamel paint. The upper hull was sprayed dark grey and when this was dry the same process was used to mask out for the fine off white boot topping line which from photos I calculated should be about 3mm.
I have an aversion to intense white on these older models which I have previously explained on this forum.

The colours I used were:-

Humbrol Matt Black Ref 33 (Below waterline).
Humbrol Matt Dark Grey Ref 32 (Above waterline).
Humbrol Matt Camouflage Grey Ref 28 (Boot topping and ID numbers).

The BECC self adhesive numbers were carefully painted before they were applied and the black shadow was added with a fine marker pen.

The completed model was spray finished with satin finish polyurethane varnish. This brings all the paint to the same level of “mattness” if you know what I mean. It also seals the vinyl numbers and protects the whole model as it will be getting wet.

I will post some more close up picture taken in day light as soon as I can.

Very impressive work.

Hi all


The last few pictures posted (with the model in primer) were mainly for the followers who wanted to see the model’s external detail in its nearly complete state. As the model is painted up in black and dark grey it will be more difficult to pick out the detail particularly, in pictures.

The “great workshop search” located the air brush and the lower hull was sprayed matt black. Next I will be drawing in the water line and reaching for the masking tape.

Mick

When I was a kid I used to stick my plastic aircraft kits together in a real hurry and then find I had left the pilot or some other major component out :scratch:

I guess things like this help you learn. Certainly when scratch building you have to think two, three of four stages ahead.

These days I plod along at a steady pace thinking carefully about the procedure for the next stages. That is unless I have a slight burst of speed and end up making a blunder (see the previous hitch with the diving mechanism fouling the prop!).