Krick Type VII kit

[mikew8760]

Hi,
New to this forum, and r/c model submarines! I've just acquired the Krick kit as it seemed the most reasonably (?) priced and a good introduction to subs. However, the instructions are atrocious, with a fair amount just skated over, or just ignored. I can accept that an experienced builder would not need a detailed description of every part and stage of the build - but I expected better from the Fatherland. ( I soon deduced that 'backboard' is port, but the original surely didn't even need to be translated into Chinglish?)
I wondered if anyone has had any experience of this kit, and perhaps some hints and tips so I may avoid turning it into a large, odd-shaped paperweight?

Regards,
Mike W

[Ralph --- SSBN 598]

Re: Krick Type VII kit

I have never seen a Krick Kit.

With a little information as you go, some on this forum should be able to help.

The word "Backboard" to me does not mean right or left side of boat.
"Backboard" to me is the stiff board used to build the subject on.
It keeps everything straight during the build until it's time to remove from the backboard to continue the build.

So I would read it as "Backboard = "Building board"

example of a building board with frames on it.

[ober freak]

Re: Krick Type VII kit

Hi Mike,

I have seen that kit once, years ago in a 3/4 build state. But don't know if there are any tricky sections.
The finished model is only a semi scale type VII look alike.

@ Ralph: Mike seems to have an german instruction where "Backbord" means "port side".
Your "building board" would be "Baubrett" or the more maritime term "Helling" in german.

As I'm german, I could probably help you with your instructions Mike, so don't hesitate to ask.

Marco

[Ralph --- SSBN 598]

Re: Krick Type VII kit

Marco, thank you.

I did get one thing right.....help from other forum members would be coming.

[bigdave]

Re: Krick Type VII kit

There were also two different Krick kits.
The original which is mostly carved from wood in a Bread-N-Butter type construction.
Then using a fiberglass top section.

The newer type Krick kit which is all plastic made from vacuum form parts like Robbe does.

I am guessing Mike is referring to the newer kit. BD.

[subdude]

Re: Krick Type VII kit

Dave,

The early Krick kit of "bread and butter" construction was a Type 2. The ABS kit is a Type VII

[bigdave]

Re: Krick Type VII kit

I thought they were both just referred to as U boats?
Like my Italian U boat kit.
Sort of looks like a type 2 but not really.
I got the Krick right anyway. BD.

[Guest]

Re: Krick Type VII kit

I've seen two or three built up. One sank all the way to the bottom on its maiden voyage, and the other gave its owner a few grey hairs. The third one seemed to be dependable but was owned and run by an experienced builder.

It can be made into a decent runner, but would I recommend it to a beginner- not on your nelly.

[mikew8760]

Re: Krick Type VII kit

Hi guys, many thanks for all your replies and kind words. I got the kit on eBay (UK) for a lot less than the usual retail price. It was clearly started by someone who had realised it was possibly too ambitious, since in three years s/he had only cut out a few of the ABS parts. Unfortunately a couple are missing, like the forward dive planes, but I think I can make them up, possibly in brass sheet.
One of the points that is ignored is the operation of the flood tank. The kit comes with a Graupner zahnradpumpe (gear-pump) to fill the tank and a brief descriptions of tube connections, but no indication of the mode of operation. From what I can see from the full-scale plan, if once filled and the 'schnorkel' (my term) sinks below water level it's a one way trip to the bottom. It seems I too have started on a voyage of discovery!!

Kind regards,
Mike W

[Ralph --- SSBN 598]

Re: Krick Type VII kit

Trimming the boats is very important.

You will use the tank, lead weight and flotation foam to trim the boat.
You will need to trim the boat to run on the surface at waterline. The ballast tank when full of air will need to bring the boat to the water line. If the full tank does not do that, then you add foam below the water line in the hull. But to make sure the center of gravity is maintained, you add weight in the very bottom of the boat and more foam to bring it back to the waterline.
You will need to trim the boat to have some of the boat above the water when the ballast tank is completely full of water. About 1/2" or so depending. To do this requires adding weight and foam.

With the boat trimmed with just 1/2" above the water when tank is completely flooded, it will take very little forward movement and little down forward planes to dive the boat below the surface. Very little up planes to bring the boat back to the surface to get air to get the water out out of the ballast tank.
Also you should be able to stop forward motion and the boat should if trimmed correctly slowly return to the surface on it's own.

When you get to the point of trimming, more help will come once you know what is happening in the water testing and you describe it. It's a balancing act. It is also the last thing to be done before running in an open body of water where there's a chance of loss.

Just work on one thing at a time and you can avoid being overwhelmed.

[mikew8760]

Re: Krick Type VII kit

Thanks for taking the time to educate me... I'm not sure if this boat was ever intended to submerge completely. The flood tank (it sits on top of the water-tight compartment) has a brass tube extending 80mm vertically upwards. I understand from your explanation that it will therefore allow air to be pumped back into the flood tank to increase buoyancy? But if it should (accidentally?) dive more than 80mm there is no possibility of surfacing. There is no 'valve' atop this schnorkel. It seems odd that even a model sub should be designed this way, without any warning or disclaimer that it cannot, actually, submerge. Or am I missing something?

Mike W

[Ralph --- SSBN 598]

Re: Krick Type VII kit

I am not familiar with the Krick systems.
If your instructions have a drawing, it should help to understand how the system was designed to work.

There are many different ways to make a sub work.
Some look very similar but may work completely opposite from each other.
Just depends on what motors and pumps are used and the direction of water or air is to flow.

As you get in to the build more, the systems should start making sense.

It helps if the drawing shows the tank's condition when on the surface and completely submerged.

Most systems are designed to run full empty or fully flooded.
There are few variable systems but they usually use pistons of some type.

If you can lay out the ballast system parts and equipment and take a photo, it might help to determine what system you actually have.
I know that there are people who are responding to this thread that have been building model submarines for a very long time.
Even build kits and some even build ballast systems.

I'll let them reveal themselves if they want to.
But be assured, some of the very best builder/designers are here reading and ready to help with any issues you may come up against..

[Guest]

Re: Krick Type VII kit

The Krick uses a vented ballast system, it is used to trim the boat to a lower waterline reducing freeboard and the speed needed to submerge, but the boat should still remain positively buoyant, and you drive it under. So effectively the boat remains a dynamic diver. How much positive buoyancy remains is down to the builder, the lower the buoyancy the slower the speed you can travel underwater, however you increase your chances of losing the boat.

My advice with this boat is to keep operations at shallow depths and where possible operate in water where the boat can readily be recovered if the worst happens.

If you wanted to keep things very straightforward, you could build the boat first off as a surface runner, then a dynamic diver by hooking up the hydroplanes and trimming the boat to decks awash (any higher and the boat won't go under), then finally add the ballast system.

My main gripe with this boat is the flimsy construction of the pressure hull. This is the area that needs most attention when building.

[mikew8760]

Re: Krick Type VII kit

Thanks, again for taking the time to respond. I had been talking to someone who had one of these boats at a model show, but just before mine arrived. He was unimpressed by the overall quality of the kit, which he had built some time previously, and had since lost interest in. I understand your comments about trimming, and this seemed to be this guy's main frustration with his boat. He warned about air bubbles trapped in various places, so that apparent neutral buoyancy became negative when diving..... To be honest, I'm not too concerned, as I expect not to run fully submerged, just decks awash - or a little more! ( I don't have access to gin clear water in a swimming pool.)

One further point that seems to be glossed over concerns the radio gear. I never 'upgraded' to 2.4GHz, and still have 30 year old 27MHz AM kit that I intend to use. I believe the aerial (longish piece of wire) may be arranged around the inside of the watertight compartment, and reception will still be adequate at small depths of water, but not salt water? It would be useful to hear of any pitfalls I may avoid.

Regards,
Mike W

[ober freak]

Re: Krick Type VII kit

My club doesn't have access to a clear pond, so run my subs in our natural pond with a fresh water bypass and sometimes lakes.
I have attached long antennas to my subs for some better submerged visibility, but you have to concentrate when running below periscope depth. It's a little thrill for me to run them at the visibility border, and surface in a place spectators didn't suspect them.

2.4 or 5 GHz won't work at all below surface, 40/75 MHz FM is the preferred system, 27 AM will work too, but is more prone to noise and interference.

That gear pump system will work also, but you have to fill it completely or need to block at least 1 hose to prevent further filling when submerged.
I use an air vented hose pump system on my Robbe Type VII which is very similar, but my pump is self blocking when not needed. I fill my tank to rest buoyancy where turret deck is about 1" above the water. It could dive in this state at lowest speed. And will rise by itself form 1ft below surface in about 10 seconds at full stop.

You should open the deck vents to prevent trapped air, a step which is missing in the instructions.

And remember, as your pressure hull is not in a circled shape and not very thick either, your biggest thread is depth and trapped air.