Krick Type VII kit

[mikew8760]

Re: Krick Type VII kit

Been away for a few days, so just catching up on replies - many thanks. But, can you confirm that the receiver antenna (that long piece of wire on 27MHz) should be strung out around the inside of the WTC? I'm just a bit concerned that such an arrangement will make it susceptible to picking up all the interference from motors and suchlike; is there any way of minimising this? I assume there is no point in trying to arrange for an external antenna?

Regards,
Mike W

[JWLaRue]

Re: Krick Type VII kit

Mike,

It isn't absolutely required to run the antenna wire outside of the dive module and in the 'wet' space. In either case, noise suppression due to the motors can be essentially eliminated through the application of ceramic capacitors. Three are usually used: one between motor negative and the motor case, one between motor positive and the case, and the third one between the two terminals.

If you do choose to run the antenna make sure that whatever you do that you do not change the overall length of the antenna and that the antenna is completely insulated from the water.

-Jeff

[mikew8760]

Re: Krick Type VII kit

SubCulture
I get the impression you may have some experience of this kit ? If so, perhaps I could ask a couple of questions...
I seem to be missing parts for the conning tower! I reckon I can make up something to 'fill the gap', but the instructions and diagrams become more inscrutable the more I study them.
1. I presume the removable section of the hull requires a hole cutting in it for the 'bulge' of the flood tank to protrude into the conning tower?
2. And hence that the ventilation tube from the flood tank then becomes the 'periscope'?

To get this right ideally would require some accurate measurements indicated on the plan, or possibly a cutting template. Also, there is no proper indication as to how the flood tank is fixed in place; I assume it just sits on top of the WTC and is held in place by a close fit of the upper part of the hull.

I still find it hard to believe that these instructions have been produced by those who are otherwise well-known for attention to detail and accuracy. I must get by Berliner pen-pal to find out if there is a German version of them, although I've trawled through the Krick web-site and found nothing.

Regards,
Mike W

[ober freak]

Re: Krick Type VII kit

Hi Mike,

I found this: "Der Tank kann zwischen den Deckelbefestigungsmuttern verkeilt werden und wenn Sie sich über die genaue Position im Deck klar sind auch dort von unten mit doppelseitigem Klebeband eingeklebt werden." in the instructions.
translated: "The dive tank can be stuck between the hatch locking nuts and when you know it's exact position below the deck you can also glue it to its bottom side with double sticky tape."

Here is the link to the instructions I found from Krick http://www.krick-modell.de/shop_fachhan ... 310_01.pdf

Marco

[mikew8760]

Re: Krick Type VII kit

Vielen dank, Ober Freak, das ist echt super! I've run some of the sections through Bing (my schoolboy German is now very rusty) and it's clear some sections are omitted from the instructions I have. However, I still cannot find any details of the shaped hole needed to accommodate the bulge in the flood tank; it simply says " glue the tower to the deck". Perhaps I'm missing something?

Again, thanks for taking the trouble to search the Krick site - I was obviously looking in the wrong place!

Regards,
Mike W

[Guest]

Re: Krick Type VII kit

I've seen four of these models built up, not owned one myself.

As the man said by three methods we may learn wisdom: First, by reflection, which is noblest; Second, by imitation, which is easiest; and third by experience, which is the bitterest.

[richard]

Re: Krick Type VII kit

Mike, I have the original instruction book in German if it's of any use to you...you are more than welcome to it. If you send me your postal address via a pm, I'll post it to you.


Rich

[mikew8760]

Re: Krick Type VII kit

Richard: Thanks for the offer of the Anweisungen in German, but I think the link provided by Ober Freak has given me the same thing.
Also, the previous comment about the pump; I had expected the one supplied to be a peristaltic type, but it's actually a Graupner gear pump. I've yet to try it pumping water, but it does seem that it would not 'leak' water back into the flood tank when the 'schnorkel' is submerged. I wonder if anyone can confirm this?

And now, for something completely different...
I remember from my distant school days something called a Cartesian diver; a carefully weighted small bottle with an air bubble inside a larger, plastic pop bottle filled with water. You squeeze the pop bottle and the 'diver' sinks, let go and he rises. Now, if you have a sufficiently deep pop bottle and you can get the diver to sink below a certain depth then it reaches the point of no return, and continues to sink to the bottom. I suppose the same holds true for a (model) submarine, but particularly one that does not have compressed air to blow the flood tanks. I shall google to try and find the parameters that define this point of no return to make sure all my hard work doesn't sink without trace on first voyage; (see a previous post....) Again, I imagine this is all well known to submariners?

Regards,
Mike W

[ober freak]

Re: Krick Type VII kit

The "Cartesian diver" Problem only occurs to non round WTCs especially with thin vacu formed parts like yours. You shouldn't go deeper than some feet! A Polycarbonate sheet (100x300x5mm / 4x12x0.2") will bend in a depth of 1m / 3ft about 8mm / 0.32" which result in a volume loss of about 0.1 L / 6 cuin (Data from the book "Technik der U-Boot Modelle" by Norbert Brüggen). Round WTCs will reach their crushing depth with just an merely measurable amount of volume loss. A cylindrical WTC from GRP with a diameter of 100 mm and a thickness of 1.13 mm will shrink just about 3,6 µm (micrometer) in a crushing depth of 8 m.

To your question about the conning tower position the instructions say a little in the section "Aufbringen des Zierdecks":
Schneiden Sie sorgfältig den Ausschnitt für den Turm (64) aus und zwar so, dass dieses Turmteil genau in den Decksausschnitt passt.
-> Cut out the area for the conning tower (part 64) that it will fit flush into the cut out.

Is there probably a marking for the conning tower in the deck parts (parts 60 to 63)?

The instructions say that with a full tank the stern should be below water but the bow should be 1/2" slightly less above. So the tank is only supposed to be used in either full or empty state. Nothing to worry about the pump type. The only thing is you can only empty your tank when the snorkel reaches the air.
I drive my Robbe Type VII in the same way.

Marco

[mikew8760]

Re: Krick Type VII kit

Ober Freak: I only just noticed you are in Hamlin; we visited there last Christmas for the Markets and had a great time...
Thanks for the feedback re the little diver. I don't think it would ever be a problem, although I was thinking of comments from an owner of the same model who said the hull tended to trap bubbles, even with all the holes.

My problem at the moment is that I am missing some ABS parts for the conning tower! I (foolishly?) got the kit as an 'already started' project and only now discover they are missing; another lesson learned!

Regards,
Mike W

[Guest]

Re: Krick Type VII kit

Norbert's book promotes best practice and tends to be rather black and white.

Keep the boat in relatively shallow depths (two or three feet) and it will be fine, it's if or when you start going down the deep end of swimming pools you may get a nasty surprise. The krick boat isn't the right kind of design for that type of sailing.

A peristaltic pump would produce slow dive times. They work well enough for small ballast volumes, but for bigger tanks a geared pump is a better choice.

[Guest]

Re: Krick Type VII kit

Something else to add, I see you're a registered user and not a member.

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