Gwen's Arkmodel 1/48 scale RC Type VIIC build log

[Gwenydd]

This is the beginning of my thread for the build of my radio controlled Arkmodel 1/48 scale Type VIIC U-boat. I Purchased the kit for the sub on Amazon from Arkmodel (in China) for around $380. I had a Watertight Cylinder sub driver system custom built for me by Nautilus Drydocks (You know... "Bob Martin, the RC Sub Guy" on YouTube). The WTC system has a brushless drive motor with a gearbox to drive two counter-rotating propellers, servos for the forward and aft dive planes, rudder, and one extra output which I will probably use to open and close the bow cap doors for the torpedoes. I also have an automatic pitch control board which directly controls the aft dive planes automatically to keep the sub level at all times unless it receives an override from the transmitter to move the aft planes. And last but not least - I have a small emergency ballast blow tank that can be pressurized with canned airbrush propellant to do an emergency blow of the ballast tank in case I can't get the sub to re-surface. The entire WTC system with motor, servos, and other subsystems cost me around $1100 total. Not cheap but I prefer to spend a little more to make sure I don't lose my investment due to not being able to re-surface the boat.

The boat is 1.4 meters in overall length (55") so I can barely stretch my arms far enough to touch the bow and stern at the same time. This is going to be a lot of fun! Unlike most sub model kits this one was specifically designed for RC use. It has all the flood vents pre-cut through the outer hull, and proper mount points for the control surfaces to function.

I just received my kit and WTC packages a few days ago and have started working on the build. I'll get some photos shot and post another update later today.

:Kaleun_Salute:

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12766

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12767

[Gwenydd]

The kit is made of some type of ABS plastic so it is not nearly as brittle as styrene. I think it will make for a very tough RC model.

I decided to start with the conning tower build. I have it mostly together now with the exception of filling a few small gaps and adding some details that were not included in the kit. You can see I already added the small (silver for now) hand railings at the front sides of the wintergarten. All the brass parts you see in the photos are photoetched brass parts which are included in the kit.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12768

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12769

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12770

Here you can see a test fit build of the stern control surfaces and related support structures.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12772

You can see that there is very little room in the stern for the rudder control horns. It takes some fiddling and reshaping of parts to get moving parts to not interfere with each other.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12776

Here's a bit of a size reference photo with the hull on top of my Virtual Pinball cabinet and with my U-boat kaleun's hat.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12771

[Gwenydd]

So, for anyone who isn't already familiar with this stuff, this is what the insides of most static diving RC submarines look like. Static, as opposed to Dynamic diving, means that the dive system is capable of allowing the submarine to dive without needing to move forward or backward and pushing itself down using the dive planes. Static systems dive by changing the overall buoyancy of the boat, so static diving systems tend to be more complex than dynamic systems.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12778

This is the WTC or Watertight Cylinder containing all the electronics, batteries, radio gear, motors, servos, etc. to operate the sub. Mine is a 3" diameter tube with an 8" long ballast tank. If you do the math it works out to 56.55 cubic inches of volume or 2.039 pounds of water at 70 degrees. At least until I become proficient at operating the sub safely I will keep it set up to only flood to neutral buoyancy, which means I can operate pretty much normally using the dive planes (along with forward motion) to dive and surface before blowing the tanks. Later I may set it to allow for some negative buoyancy to allow quicker dives and diving in place... we'll see how it goes.

This is the forward section of the WTC which contains forward dive plane and torpedo door servos as well as the radio receiver, battery, a battery and radio signal monitor board, and wireless on/off switch for the sub that uses a key fob to activate.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12782

This is the center section which is the ballast tank. The brass cylinder in the middle is a canister that can be filled with compressed airbrush propellant to emergency blow the tank. The tank vent is a small brass tube on top with a valve which is activated with a servo motor to allow air out of the tank and for the tank to flood. The large opening on the bottom of the tank allows water to enter as well as providing maintenance access. You can see the wiring for main power, servo motor, and engine controls running through an airtight tube that runs all the way through the ballast tank at the top. The airtight tube also allows the pressure inside the forward and aft WTC compartments to equalize.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12780

And this is the aft section of the WTC containing the main drive motor and ESC, aft dive plane servo, rudder servo, two air pumps for blowing the ballast tank, and an electronic auto-leveling board connected to the aft dive planes.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12781

I have already done a bit of setup on the WTC, mostly involving running wires and connecting servos and the subsystem control boards.

And last is a view of tha aft end of the WTC showing the control pushrods and gearbox to drive the twin propellers. The brass filler valve on the hose to the right allows me to fill the emergency ballast blow tank with airbrush propellant. The other two hoses are for the ballast air intake and pressurization testing.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12779

I have been building various types of RC vehicles for many years and this one is the most complex system-wise I have done so far. There's a lot of stuff to set up, program, tweak, and maintain. Much more than an RC airplane or tank.

More to come on this subject as the work progresses...

[Gwenydd]

I decided today I just wasn't comfortable with the fragility of the railings on the Arkmodel Type VIIC so I am replacing all the plastic railings with soldered brass ones. Also the wintergarten railing wasn't quite shaped right so...here's my start on the wintergarten upper rail replacement. I'm waiting for more brass rod to arrive in the mail before I proceed any further because I'm all out...

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12783

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12784

[Onkel Neal]

Oh boy, I have been waiting for this:Kaleun_Thumbs_Up:

The Arkmodel is designed fopr RC use, then? On the stern planes and rudders, the small screws are part of the kit out of the boy? What material are the threads the screws screw into? Are they metal or plastic? Or metal axle shafts?

[Gwenydd]

Oh boy, I have been waiting for this:Kaleun_Thumbs_Up:

The Arkmodel is designed fopr RC use, then? On the stern planes and rudders, the small screws are part of the kit out of the boy? What material are the threads the screws screw into? Are they metal or plastic? Or metal axle shafts?

Yes, it was specifically designed for RC use. Yes, those small screws on the control surfaces are included in the kit. They screw directly into the end of the control surfaces which are made of ABS plastic, so you have to be very careful when installing or removing them not to strip them out. I am probably going to make a set of metal threaded inserts (or maybe just use nuts) and drill out the holes larger and glue them in place so I have a more durable connection. The shafts for the control surfaces are all steel rods and the mount points on the hull have brass bushings for them to fit through, so they all turn pretty smoothly and without wobble.

[ET2SN]

Gwen, have you tried using "loc-tite" on metal parts and screws?

Its a little temperamental when compared to the super glues, but its also durable and easy to work with. You can find it in any "automotive" isle and, worst case, at any auto parts store. And, its pretty cheap. :yeah:

I've had good results using it on 1/118th scale die casts and even on some plastic models.

[Gwenydd]

Gwen, have you tried using "loc-tite" on metal parts and screws?

Its a little temperamental when compared to the super glues, but its also durable and easy to work with. You can find it in any "automotive" isle and, worst case, at any auto parts store. And, its pretty cheap. :yeah:

I've had good results using it on 1/118th scale die casts and even on some plastic models.

Sure, I always try to use a thread locker on metal to metal connections like that. But the issue here is that with an RC model it is often necessary to remove the control surfaces to fix something or make adjustments and with a metal to plastic connection the plastic WILL eventually wear out from use. So a metal to metal, ie a small screw and nut, will be much more durable and reliable.

[ET2SN]

Yeah, there's "loc-tite" then there's what I call "less-than-loc-tite" which has some fillers blended into it so the parts can still be removed.

I think all of us who have a drawer full of alum. and brass tubing for scratch building have a bottle of this stuff somewhere on the shelf. :yeah:

[Gwenydd]

thanks for the suggestion =)

[ET2SN]

Lemme dig around on Amazon, I'll be back with a link. :Kaleun_Cheers:


OK, here's what I'm talking about:

https://www.amazon.com/Loctite-Heavy-Duty-Threadlocker-Single/dp/B000I1RSNS/ref=sr_1_2_mod_primary_new?crid=32R6Z1SUP09L5&keywords=loctite&qid=1666485249&qu=eyJxc2MiOiI0LjkxIiwicXNhIjoiNC4zNiIsInFzcCI6IjQ uMjUifQ%3D%3D&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sprefix=lock%2Btite%2Caps%2C389&sr=8-2&th=1

While the joints are re-usable, you only get a finite number of "shots" before this stuff starts to build up. It isn't the best solution for a battery or servo hatch, but its great for stuff you'll only dis-assemble one or two times a year.

:Kaleun_Cheers:

[Gwenydd]

Lemme dig around on Amazon, I'll be back with a link. :Kaleun_Cheers:


OK, here's what I'm talking about:

https://www.amazon.com/Loctite-Heavy-Duty-Threadlocker-Single/dp/B000I1RSNS/ref=sr_1_2_mod_primary_new?crid=32R6Z1SUP09L5&keywords=loctite&qid=1666485249&qu=eyJxc2MiOiI0LjkxIiwicXNhIjoiNC4zNiIsInFzcCI6IjQ uMjUifQ%3D%3D&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sprefix=lock%2Btite%2Caps%2C389&sr=8-2&th=1

While the joints are re-usable, you only get a finite number of "shots" before this stuff starts to build up. It isn't the best solution for a battery or servo hatch, but its great for stuff you'll only dis-assemble one or two times a year.

:Kaleun_Cheers:

Thanks for the link, I'll take a look at it. Though I am fairly sure I will want to go the way I originally said. I just hate having to replace parts when I can prevent them from taking damage with a bit of forethought. And I really don't want to lose my $2000 sub because I wanted to save a bit of time and money. =)

[Gwenydd]

The 1mm brass rod finally arrived and I am back at work building railings. Here's what I have so far.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12804

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12806

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12805

[Aktungbby]

how much heavier is the substituted brass railing and winter-garden brass over the kit's original plastic that it won't affect stability when you finally launch the vessel in water?

[Gwenydd]

how much heavier is the substituted brass railing and winter-garden brass over the kit's original plastic that it won't affect stability when you finally launch the vessel in water?

The brass is of course heavier but it won't affect the final result really since I can simply use a little less ballast weight or a little more foam when trimming the boat to compensate.

[Onkel Neal]

Do you glue brass parts together or braze them? Looks great, Gwen.

[Aktungbby]

I decided today I just wasn't comfortable with the fragility of the railings on the Arkmodel Type VIIC so I am replacing all the plastic railings with soldered brass ones.

Do you glue brass parts together or braze them? Looks great, Gwen.:doh: Of course she solders... 'brazen' :subsim:ing is forbidden!:arrgh!:

[Gwenydd]

Do you glue brass parts together or braze them? Looks great, Gwen.

I'm using silver solder and a propane torch. I built a little wooden jig to hold the wintergarten parts in position while I soldered them. It was still pretty tricky at this scale. =)

[Gwenydd]

I now have all the brass railings built except for the main side railings on the conning tower and a couple details on the deck rails. I also decided to try making my own cloth scale Kriegsmarine flag so I found an old piece of fine woven cotton bedsheet, ironed it nice and smooth, and backed it with a sheet of adhesive vinyl to make an 8.5x11 size printable sheet. I then ran it through my Canon inkjet printer and it actually worked really well. I carefully cut it out and removed the vinyl backing and sealed the edges with CA glue so they wouldn't unravel and folded it and carefully glued the edges only together. Now I have a pretty nifty little homemade all cloth flag that looks darned good if I say so myself. The flagstaff is removable from the holder on the back of the wintergarten and I will mostly just use it when displaying the model.

*Note to admins: if the historically accurate flag image presents an issue I will be happy to modify the image so as not to offend anyone.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12809

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12808

[mapuc]

Not if I had something to say-because for me it indicate that you are building your model 100 % historical correct.

About the model-What is there to say other than-You have done a great job so far.

Markus

[Onkel Neal]

You work fast, it's looking really good. What's the status, model 75%, R/C ..% ?

Great work!:Kaleun_Thumbs_Up:

[Aktungbby]

I love the flag; but I like that background Kaleun's hat even more!:Kaleun_Salute:

[Gwenydd]

I finished the conning tower side railings today.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12813

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12812

[Gwenydd]

You work fast, it's looking really good. What's the status, model 75%, R/C ..% ?

Great work!:Kaleun_Thumbs_Up:

I'm not really moving all that fast. I would say the model build is maybe 50 percent complete right now. The decks are just fitted on the top of the hull for now and I still need to add a set of magnets to hold them in place. I have to finish the torpedo door opening mechanism, glue the forward hull section together and then I need to fill cracks and seams, final sanding and cleanup, and then paint work. I'm probably forgetting a few things along the way... I am still trying to locate a 75 mhz 6 channel receiver but the WTC and electronics build is otherwise 90% finished.

I didn't mention this before but RC subs require low frequency radios to function under water. Modern 2.4 ghz signals won't penetrate the water. So I have to use what would now be considered "antique" radio gear for the u-boat. The 75 mhz frequency band is the FCC authorized range for "surface" vehicles which also includes boats and submarines. Sadly, nobody makes 75 mhz RC radios any more... so I pretty much have to scour ebay for them.

[Gwenydd]

Here's a tip for modelers: if you need to add rigging/wires/cables that need to stay stretched tight try using stretchy bracelet maker's cord. It's made of silicone rubber or something similar, is pretty strong, and nice and stretchy. It's also pretty cheap.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12818

[Gwenydd]

Today I worked on what has to be the trickiest and most difficult part of the build. First I had to trim out 4 bulkheads inside the hull (2 at the forward end of the center section and 2 at the forward end of the aft section) to make room to install the WTC into the hull in the proper position. That was the easy part.

Here you can see where I ground out the two bulkheads on the aft section:
https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12823

The difficult part was grinding down the inside of the hull right in front of the exit point for the two drive shafts. I had to do this to make clearance for the universal joints on the drive shafts so that I could shorten the shafts enough to make the turn to connect to the gearbox on the WTC.

Here is where I had to grind out clearance for the U-Joints:
https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12819

And here you can see the drive shafts installed in their proper positions:
https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12826

I replaced the delrin bushings for the drive shafts with brass tubes because the delrin was sticky and didn't allow the shafts to turn smoothly.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12825

And here you can see the finished rudder control mechanism.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12827

[Onkel Neal]

Wow, tiny U-joints.:yep:

[Gwenydd]

Still working on all the various linkages to get everything working smoothly and with full travel on the controls.

Here's the aft end of the WTC in the hull where it connects to the drive train and servo pushrods.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12830

The servo movement wasn't enough to get full travel on the controls so I had to add a few levers to increase the travel.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12831

I am continuing to tweak the linkages to get everything working as it should.

[mapuc]

Are you going to add a camera linse in front of the sub or somewhere else pointing forward ?
I remember a friend from a hobby club who put a fisheye linse on his sub.

I presume you are constructing the sub being able to dive will it be static dive or dive by driving(can't remember exact phrase)

Markus

[Gwenydd]

Not planning on a camera right now. If I did add one I would make it mountable on the deck gun mount. I used a magnetic mount for the deck gun so it can just be pulled right off the deck and replaced with a camera easily if I want to.

If you read the post on the first page of my log about the WTC it explains all about how the sub will work. (Hint: it's static diving - that's why it has a ballast tank and pumps).

[Gwenydd]

I finished adding some scratch-built antenna rigging bits on the conning tower (since they were not included in the kit), also cut out a few holes through the hull and added some inside details.

Here it is with with the primer coat. I am priming the entire sub with red oxide so I can use a resist applied in selected locations to simulate rust on the boat when the finish coats are on.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12835

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12834

[Gwenydd]

I have the paint and weathering on the conning tower nearly finished. I need to tone down the reds a little on the rust areas with some browns. But it's pretty much done now.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12836

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12838

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12837

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12839

[ET2SN]

Not jealous, not jealous, not jealous.. :O:

:Kaleun_Cheers:

Just curious, what are you using for a final top coat? Clear enamel or maybe even two-part Epoxy? :hmmm: That puppy is supposed to get wet.

[Gwenydd]

Not jealous, not jealous, not jealous.. :O:

:Kaleun_Cheers:

Just curious, what are you using for a final top coat? Clear enamel or maybe even two-part Epoxy? :hmmm: That puppy is supposed to get wet.

The topcoat is flat clear enamel.

[Gwenydd]

I have been working on building and fitting the magnetic mounts for the deck plates (not a part of the kit design) and connecting all the linkages for the various control surfaces.

Here's a quick video of a control systems check on the boat. I forgot to show the ballast system in operation, with the vent opening to flood the tank and the ballast pumps running to blow the tank. I'll do that in another video.

https://youtu.be/5Bo1DR0nsfw

[Aktungbby]

Nice

[Onkel Neal]

Wow, I love the scratchbuilt turnbuckles on the antennae :Kaleun_Thumbs_Up: cables. Looking good! The lights are a good idea, and U-boat captains probably did run then in harbor.

Now we need you to launch the sub and measure turning radiuses so we can solve an argument in the Destroyer Uboat Hunter forum :haha:

[Gwenydd]

I'll be happy to help you solve your turn radius question, however my results may not completely correspond accurately to the real sub since I don't have independent motors for each propeller. I have one motor driving both propellers with a single gearbox, whereas the real boats could increase their rates of turn by using differential prop turns.

[Gwenydd]

I am continuing work on painting the hull now. I started with a red oxide primer for the rust and then used a laser level to mark the waterline on the hull and painted the upper hull and rust. I still need to finish the magnetic attachments for the forward deck. And I need to find the right dark grey paint for the lower hull.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12855

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12856

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12857

Update: After looking at the cord I used for the deck railing cables I realized they were way too thick so I replaced them with some black nylon thread.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12858

[Onkel Neal]

Nice, looking really good, Gwen.

[Aktungbby]

what are the black wires on the conning tower for specifically.

[Gwenydd]

what are the black wires on the conning tower for specifically.

Those are the rigging cables that attach to the radio antennas.

[Gwenydd]

I finally finished building the magnetic mounts for the forward deck plate and found the gray I needed for the lower hull. So here's the boat with the hull in the proper colors and with the rust base color finished. Note: the photos make the colors look a fair bit lighter than they really are because of the very bright light on the ceiling above...

I also finished building the forward antenna rigging. That stuff is a real pain in the butt to do with those teeny tiny little insulator blocks...

Now I have a bunch of weathering paint work to do to blend the rust and add more variation to it. Then I need to paint the scum line on the hull and add some salty residue =).

(I fixed the dark streaks on the saddle tanks after taking the photos.)

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12867

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12868

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12870

[Onkel Neal]

Looks really good, Gwen. The rigging and insulator blocks, the super straight periscope, handrails, lots of great details. How did you do the small cable wrapping the deck gun barrel? Tell me thats a wire or something you wrapped around the barrel, cuz I cannot see how it could be a painted on detail. :o

Weathering is next, eh?

[Gwenydd]

Looks really good, Gwen. The rigging and insulator blocks, the super straight periscope, handrails, lots of great details. How did you do the small cable wrapping the deck gun barrel? Tell me thats a wire or something you wrapped around the barrel, cuz I cannot see how it could be a painted on detail. :o

Weathering is next, eh?

I replaced the tip of the barrel with a matching diameter aluminum tube, made a plug to fit it and used a piece of nylon thread wrapped around the barrel. No paint needed =P Oh and the periscope is nice and straight because I made it myself out of an aluminum tube. I actually turned the shape of the head of it from aluminum rod using an electric drill and a file and added the lens housing. The periscope tube also functions as a snorkel for the ballast air intake. There's a small hole drilled in it toward the top of the tube.

[Gwenydd]

I decided I was really too heavy handed with the rust on the lower hull so I hit the lower hull with a few light mist coats of dark gray again. This really toned it down a lot and I think it looks much better.

I also realized that the hatches and bollards/mounts should all match the very dark grey of the decks so I fixed those. I need to redo the paint wear with wood colors showing through on the decks again and blend it all.

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12874

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12875

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12877

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12878

Here you can see the tiny magnets I used to attach the antenna rigging to the tripods.
https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12876

[fireftr18]

Awesome job. I will love to see it when it's actually operational.
:Kaleun_Cheers:

[Gwenydd]

Awesome job. I will love to see it when it's actually operational.
:Kaleun_Cheers:

Thanks, Once I finish the paint work it will be ready for trimming. I'm going to need to get a tank put together for that and then I'll get the surface and submerged trim adjusted using lead weights and foam. After that I'll have to wait till the weather warms up enough again to put it in a pool or pond for "sea trials"...

[Gwenydd]

For anybody who is interested here are the pertinent specs on my boat:

Kit: Arkmodel 1/48 scale German Type VIIC U-boat purchased from Arkmodel on Amazon. This kit was specifically designed for radio control.

Length = 55 inches
Height from bottom of keel to top of conning tower = approx. 8.5"
Beam = approx 6"
Weight of completed model with WTC, battery, and all equipment for running installed = approximately 12 lbs. (this is my estimate. I'll actually weigh it later)
Ballast tank volume=56.55 cubic inches, equivalent to 2.039 pounds of water at 70 degrees F
Propellers are brass 1/48 scale Type VIIC props purchased from Nautilus Drydocks.

Watertight Cylinder built for me by Nautilus Drydocks. Includes 1 electric motor and gearbox to drive two propellers, 4 servos (2 forward and 2 aft) plus additional servo for ballast vent valve, two ballast air pumps, and a gas charged pressurized cylinder for emergency ballast blow in case of loss of radio signal or if manually commanded.

The on-board battery pack is a 3300 MAH LIPO.

I have added the following additional devices to provide more functionality to the sub:

AD2 Automatic Pitch Controller Board from Nautilus Drydocks. This controller board automatically controls the aft dive planes to keep the boat in a level attitude unless overridden by manual input to the aft dive planes from the radio.

Depth Cruiser controller board from Nautilus Drydocks. This board automatically maintains the last depth of the boat commanded by the radio using the forward dive planes. It has an on-board pressure sensor that precisely measures the ambient water pressure and moves the foward dive planes to maintain that pressure until overridden by radio input to the forward planes.

BLM Battery Link Monitor from Nautilus Drydocks. This board monitors the charge level of the battery as well as the strength of the signal received from the radio transmitter. If the battery level drops below a certain preset point the boat will automatically surface. Also if the radio control signal is lost for more than a preset length of time (I have it set to 5 seconds) the boat will automatically surface by blowing the tank with the emergency gas cylinder.

My radio system is a 6-channel 75mzh radio from Vex Robotics. These were designed for home-built robots etc. and put out a good strong signal. They work very well for sub models since modern high frequency radios cannot transmit a signal of sufficient strength through water.

All-totalled I would estimate I have spent approximately $2000 USD to build this boat and for the radio system it uses.

[mapuc]

I pray everything will work just fine on your sub when your take it out for a test run.

Hopefully you have or know someone who has a swimmingpool.

Markus

[Gwenydd]

I pray everything will work just fine on your sub when your take it out for a test run.

Hopefully you have or know someone who has a swimmingpool.

Markus


Thanks Markus. =)

I don't know anyone with a pool right now. I'm still looking for a good place to test it when the weather warms up.

[Gwenydd]

OK the paint work is all finished. I used some various colors of ground up pastels mixed with flat clear acrylic paint to finish the rust and deck weathering and blending of colors. Then I added the scum line by airbrusing a hazy dark green line at the waterline, then a lighter hazy green line over that one, and finally a very very light green (almost white) over that. This is to simulate algae growth and accumulation of minerals, salt, etc...

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12884

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12883

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12885


https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12881

[Gwenydd]

https://youtu.be/POFxHtMZzpI

[mapuc]

You have passed the modelling builder with an A+.

Only little setback is the weathering-It somehow looks logic in where you have added the rust to the sub. a more chaotic approach.

Nevertheless
You can be darn proud of you build.

Markus

[Gwenydd]

Thanks Markus. As for the rust, believe it or not I looked at photos of real u-boats and mostly put it in places I saw in the photos. Though I agree it could look better.

[ET2SN]

Gwen, its looking really good and I'm not saying that just because I'm jealous. :Kaleun_Cheers: :up:

Have you thought about being able to "set" the dive planes for surface trim? You'll need to putt around in a pool or small pond to find the best balance, but I'm wondering if you could set up a couple of null zones with your controller for surfaced and dived trim on the planes? :hmmm:

BTW, how about that other "model"? :D Some vids of the 7/8ths (?) scale Fokker Eindecker would be appreciated. What is turning the prop? It doesn't sound like a Rotax. :yeah:

[Gwenydd]

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12908

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12907

https://www.subsim.com/radioroom/picture.php?albumid=1411&pictureid=12906

[Gwenydd]

Gwen, its looking really good and I'm not saying that just because I'm jealous. :Kaleun_Cheers: :up:

Have you thought about being able to "set" the dive planes for surface trim? You'll need to putt around in a pool or small pond to find the best balance, but I'm wondering if you could set up a couple of null zones with your controller for surfaced and dived trim on the planes? :hmmm:

BTW, how about that other "model"? :D Some vids of the 7/8ths (?) scale Fokker Eindecker would be appreciated. What is turning the prop? It doesn't sound like a Rotax. :yeah:

I'm not really sure what you mean about the dive planes. I can easily adjust the plane trim during operation. As for trimming the boat (ie. adding ballast and bouyancy) I do need to put it in the water to adjust that.

My airplane is actually a 3/4 scale replica. The engine is a Volkswagen 1915cc 69 HP flat four with a custom aircraft carb and electronic ignition. It has a 2:1 reduction belt drive turning a 72" custom made replica wood prop.

Here are a few videos for you taken during my 2007 test flights, note the guy talking is my friend and former flight instructor Bill. He was talking to the camera really and not directly to me since I didn't have a radio in the airplane when I was test flying it.

https://youtu.be/wgOLvMzyMnQ

https://youtu.be/6XIPPYdKIdUhttps://youtu.be/6XIPPYdKIdU

https://youtu.be/2pCk9gdr5dg

https://youtu.be/Wj2dcut0LLw


Gwen

[Onkel Neal]

Wow, that's cool, Gwen. Something I would never do, I don 't like heights :)

[ET2SN]

I'm not really sure what you mean about the dive planes. I can easily adjust the plane trim during operation. As for trimming the boat (ie. adding ballast and bouyancy) I do need to put it in the water to adjust that.


Gwen

Woo... OK, I'm trying to avoid a reply that looks like a twelve paragraph thesis. :03:

For the record, I have ZERO experience with bow planes. Both of the boats I was on ran fairwater planes and fairwaters don't effect trim, they only provide linear up/down movement.

Anyway, when the boat is on the surface (rigged for surface) the planes tend to get locked at a certain amount of upward trim. This makes the hull more efficient in terms of how it planes through the water. In other words, you want the bow to be riding high. When you dive, you want the boat to remain mostly level. I was wondering if you could program your planes for a surfaced condition?

[Gwenydd]

Wow, that's cool, Gwen. Something I would never do, I don 't like heights :)

I love to fly. I first soloed when I was sixteen back in Ohio. I was lucky enough to be friends with a National Guard helicopter pilot who was also a flight instructor and he taught me.

[Gwenydd]

Woo... OK, I'm trying to avoid a reply that looks like a twelve paragraph thesis. :03:

For the record, I have ZERO experience with bow planes. Both of the boats I was on ran fairwater planes and fairwaters don't effect trim, they only provide linear up/down movement.

Anyway, when the boat is on the surface (rigged for surface) the planes tend to get locked at a certain amount of upward trim. This makes the hull more efficient in terms of how it planes through the water. In other words, you want the bow to be riding high. When you dive, you want the boat to remain mostly level. I was wondering if you could program your planes for a surfaced condition?

Ah I see what you mean. I don't need to worry about that. My boat is set up so that the forward dive planes are used to primarily control depth and the rear dive planes to primarily control the pitch of the boat. Each set of planes has a controller board connected to the servos for it. The aft plane controller board automatically controls the planes to keep the boat in a level attitude unless I override it with control inputs. While the forward plane controller board uses a barometric pressure sensor connected to a hose that samples outside water pressure. The board automatically controls the forward planes to hold the depth last commanded with the forward plane controls.

If you look at the waterline on the type VII U-boat you see that the bow is naturally riding a bit high when the waterline on the boat matches the actual waterline - and that is the pitch level the aft planes will seek.

Makes sense?

PS - Hope you enjoyed my test flight videos.

[Kapt Z]

I love to fly. I first soloed when I was sixteen back in Ohio. I was lucky enough to be friends with a National Guard helicopter pilot who was also a flight instructor and he taught me.

What fun! I love flying, but never found time, money...etc to get my license.

How is that plane designated? Experimental?

:Kaleun_Salute:

[Gwenydd]

What fun! I love flying, but never found time, money...etc to get my license.

How is that plane designated? Experimental?

:Kaleun_Salute:

It's an experimental category aircraft since I built it myself. =) It does require a pilot's license and a fair bit of experience to fly.

[Aktungbby]

Do U pack your own parachute?

[Gwenydd]

Do U pack your own parachute?

No parachute, just me and the airplane.

[ET2SN]

No parachute, just me and the airplane.

Don't forget Gravity..


:k_confused:


:D

[iceno9]

Gwen - I am just about to start a build of the Arkmodel 1:48 U-boat. I would like to know more about your WTC design. For example, is there a reason you chose 3" rather than 3.5" which would have allowed 2x side by side motors rather than the one with power......it looks like 3.5" will fit, but maybe shorter length than a 3" one.

Is there a way i can message you some more questions/thoughts?

Thanks

[Aktungbby]

iceno9!:Kaleun_Salute:

[Gwenydd]

Gwen - I am just about to start a build of the Arkmodel 1:48 U-boat. I would like to know more about your WTC design. For example, is there a reason you chose 3" rather than 3.5" which would have allowed 2x side by side motors rather than the one with power......it looks like 3.5" will fit, but maybe shorter length than a 3" one.

Is there a way i can message you some more questions/thoughts?

Thanks

Hey, I apologize for not replying sooner. I haven't been on the forums for some time . I can say for sure that a 3.5" WTC will not fit in the Arkmodel hull. It's a tight fit for a 3" cylinder. And sure, you can send me pm's here on the forum or I can give you my email address if you prefer.

Gwen

[Aktungbby]

Gwenydd!:Kaleun_Salute:...after a nearly 2-year silent run! :up:

[Gwenydd]

:Kaleun_Salute:

Still alive... sorta...

... and call me Gwen =)

[Onkel Neal]

Good to hear, we'll call off the search parties :doh:

[Gwenydd]

hehe, glad to know somebody cares =)