Das Boot. The RC change up.

[ausf]

Edit: This build is now the VIIC from the movie. Photos on p3.


This'll be my modeling Opus.

Hopefully. I'll be combining everything I've learned about modeling and RC, along with a lot of stuff I haven't yet learned about O rings, couplings, peristaltic pumps and ballast chambers.

Ever since I was a kid in NYC parks watching the amazing RC boats, I've wanted a RC sub. After messing around with RC tanks and planes as an adult, it's time to put my skill where my mouth is and just at least try it.

I'm using the new 1/72 Revell Type IXC/40 as my model. A, because it's new and available at a good price and B, because it was the first Snort boat, using a snorkel to be able to run underwater on diesels. I'm too scared to go compressed gas, etc for full depth diving, I'm going to stick to going just below the surface so if everything fails, I can at least locate/recover the thing.

Here's the hull half, I already cut out a section for access, and the Lexan tube that will house all the RC gear, motors, pumps, batteries, etc. A lot of brass rod and tubes, O rings, Cup seals in my future. I'll need to create water tight end caps and a housing for the tube.

By accident, I got very lucky. I ordered the tube before I had the kit thinking there would be plenty of room, but there isn't, it just fits. And again, by dumb luck, Schedule 40 2" couplings just barely fit inside the tube, so with some routing and sanding, I should be able to get O rings in there nice and snug. Since the tube and O-rings cost as much as the kit itself, not only did I dodge a bullet, but I couldn't have chose better if I actually knew what I was doing.

Wish me luck, I'm off to open a couple of hundred holes in the hull, just like the real thing...

 

[moon puppy]

U-190, this time I'm serious.

So many questions, first one, how big a charge you going to put on the torpedoes to sink those RC boats?

 

[ausf]

U-190, this time I'm serious.

So many questions, first one, how big a charge you going to put on the torpedoes to sink those RC boats?

Because that Lindberg Blue Devil kit is still in production (40 years or so later), there are too many Fletcher class Destroyers out there waiting to pounce.

Rest assured though, my son and I have already discussed 1/35 torpedoes using 1 cell lipos and pager motors for the Italeri Vospers MTB. Should run for a solid 6-7 minutes, we'll just need a net to retrieve them.

 

[Hippy Ed]

U-190, this time I'm serious.

:hmmm

 

[Paulw]

U-190, this time I'm serious.

Once a bubble head always a bubble head :drunk :skipper

 

[lupanzer]

U-190, this time I'm serious.

Great project ...

Luiz

 

[moon puppy]

U-190, this time I'm serious.

So many questions, first one, how big a charge you going to put on the torpedoes to sink those RC boats?

Because that Lindberg Blue Devil kit is still in production (40 years or so later), there are too many Fletcher class Destroyers out there waiting to pounce.

Rest assured though, my son and I have already discussed 1/35 torpedoes using 1 cell lipos and pager motors for the Italeri Vospers MTB. Should run for a solid 6-7 minutes, we'll just need a net to retrieve them.

I built one when I was a kid but didn't motorize it. looks like it would be something fun to play with nowadays. :drunk

I'll thinking a shaped charge of Tanex7 or MEK into the hull of one of those, melt right through.

 

[ausf]

U-190, this time I'm serious.

I built one when I was a kid but didn't motorize it. looks like it would be something fun to play with nowadays. :drunk

I'll thinking a shaped charge of Tanex7 or MEK into the hull of one of those, melt right through.

Just a 10 penny nail.

With all the RC stuff so cheap these days, and water cooled brushless motors, a three prop MTB will boogie across the water. If I can work out a spring loaded tube launcher, I figure a small contact switch as it leaves the tube can start the torpedo motor. If we set up a flag on the lake beach and turn the boat it a head on run, we can see who get's closest without loosing too many torpedoes.

 

[moon puppy]

U-190, this time I'm serious.

Thing about a nail is you have to pull it out, otherwise it's pluggin' the hole.

Of course, to get your model geek on, the war head really has to be a #11 blade.

 

[Piet]

U-190, this time I'm serious.

 

[ausf]

U-190, this time I'm serious.

Small update.

I'm still waiting on a bunch of stuff to put this together, so I tried to wrap my head around making a valve to vent the ballast tank so I can slip beneath the waves, but be able to close it too, so I can fill it and rise again... :hmmm

There are a bunch of expensive commercially available electronics to do this, but I want to scratch build as much as I can and as simple as possible.

I want a servo that at one end of the travel will push a switch to start an air pump, but at the other end of it's travel will open a valve to let the air out, so water can gush in the tank and sink the boat.

Just as most of my hairbrain ideas strike, this little gem came to me around 2AM. I took two large telescoping K&S brass tubes from the spares, soldered flat stock on the ends and drilled some holes. Twist the tube to open or close the holes. I'll add a control horn when I set the servo height, but this works pretty well. At full open, it vents 500ml of air in 3 seconds. So, 1,2, I'll never see it again.

The two tubes:

Together, closed and open:

 

[Duke Maddog]

U-190, this time I'm serious.

That is a brilliant idea! What an excellent start to the New Year. I am hoping and praying it works. This is gonna rock!

 

[Pavel Zabák]

U-190, this time I'm serious.

Nice detail

P.

 

[lupanzer]

U-190, this time I'm serious.

:hmmm ...

Luiz.

 

[ausf]

U-190, this time I'm serious.

Thanks for the interest guys.

I finished drilling and opening all the drain/flood holes so I could get the hull together and start planning on how to get all the RC stuff in there. It's 42 inches long:

I cut a spare steel rod to lay in the keel as the first step of ballast:

Here's a closeup of the drilled openings, there were a lot of them in a long hull:

And here's the ballast chamber I'm planning. It'll be open on the bottom to let water in, that valve will be at the top to let air out and there will be a small water tight section in one end to hold the air pump and servo to control everything.

 

[moon puppy]

U-190, this time I'm serious.

Pretty slick, so much engineering going on. Don't you need two ballast tanks, forward and aft? And how will you sync them?

 

[ausf]

U-190, this time I'm serious.

I don't know yet regarding the tanks.

All the electronics will be sealed in at one end, the ballast at the other, I think the trick will be to balance the inherent floatation in the rear with the change in the forward. I'm flying by the seat of my pants here. I've seen builds that have multiple tanks that balance front to rear for diving and surfacing, controlled by an Arduino, but that's all way above my pay grade.

I'd opt for 1/72 lead Germans to run back and forth to shift weight like the real thing.

I have a Automatic Pitch Control on the way from Germany. It's a chip that goes between the receiver and the control servos that will sense the boat isn't level and automatically adjust things until they are. It's the one thing I was told you can't do without, otherwise the boat would be nearly uncontrollable. Which was played out in my earlier testing with the 1/144. Technically speaking, it means I should be able to direct the dive planes down, when I stop it'll keep the boat at that level until told to go deeper or surface, instead of me trying to do it myself, leading to non stop porpoising.

 

[jknaus]

U-190, this time I'm serious.


Just too cool
James

 

[moon puppy]

U-190, this time I'm serious.

I don't know yet regarding the tanks.

All the electronics will be sealed in at one end, the ballast at the other, I think the trick will be to balance the inherent floatation in the rear with the change in the forward. I'm flying by the seat of my pants here. I've seen builds that have multiple tanks that balance front to rear for diving and surfacing, controlled by an Arduino, but that's all way above my pay grade.

I'd opt for 1/72 lead Germans to run back and forth to shift weight like the real thing.

I have a Automatic Pitch Control on the way from Germany. It's a chip that goes between the receiver and the control servos that will sense the boat isn't level and automatically adjust things until they are. It's the one thing I was told you can't do without, otherwise the boat would be nearly uncontrollable. Which was played out in my earlier testing with the 1/144. Technically speaking, it means I should be able to direct the dive planes down, when I stop it'll keep the boat at that level until told to go deeper or surface, instead of me trying to do it myself, leading to non stop porpoising.

That's soo cool! I understand now why you need that forward momentum to test diving. It's not like the old movies where the boat commander says, "Set her on the bottom." and have it just float harmlessly down into the sand.

So you got a camera that can mount on it so we can see where it goes? :captain

 

[ausf]

U-190, this time I'm serious.

Thanks gents!

I have a GoPro that I strap to the dog for watery stick retrieval, I'm sure it'll find it's way behind the conning tower for some Das Boot shots once I figure everything out.

I actually should be able to flood and sink without moving forward on this, but I'm going to trim it so it's always positively bouyant so it it fails, I should at least be able to find it. At least to have the snorkel and periscopes still visible when completely flooded. The planes will drive it under, but incase it goes dead, I don't want it to just disappear on me. I don't have access to a pool, only lakes.