USS Brooklyn Build

Hi everyone. This is my first rc warship build that has been way too long in the making. My brother purchased plans for the USS Brooklyn 10 years ago (I was 8 then) and so as you can tell that didn't go far. Now that I have a bit more experience in building, I am back to make this thing happen. So the would technically be my first rc warship ever so please excuse my errors as well as feel free to offer suggestions. I am planning on arming this to the teeth according to WWCC big gun rules. So my plans themselves are fairly vague so I am using Autodesk Inventor 2016 Student Edition to fill in gaps. The plans show my rib layout as this:

This is hardly enough ribs to generate the shape I need by hand. So I put these into Inventor to help solve the issue. After three failures and 12 hours I ended up with something I am fairly proud of as it still has the ribs in the same location and shape as my plans.


I am still working on the bow and stern section as my plans are a very vague in those areas as well.
So now for the kicker, I am going to be making a fiber glass hull with windows because I plan to create at a minimum two of these (one for my brother and one for me of course). The plan is to use this cad file to make a mold. And to save me the effort of work work and having to make precise measurements by hand I am employing my 3D printer to print the mold itself. Of course I am capped at roughly 5inch long prints with this printer so I had to cut the ship up, which is still in process but here it is as of now.

This method means breaking up the hull mold into 13 parts including the bow and stern prints. So far I have completed the front two prints.

The prints are close but still a bit rough, I am waiting to clean them up until after I get the whole thing printed and coated in bondo.
As for electronics I am planning to run you run of the mill parts except for the radio system. I am designing an Arduino based 2.4ghz system for a controller to give me a bit more control over the ship. I hope you guys enjoy my build.

 

I can say that I'm going to enjoy watching the build come together. Great work!
I don't know if you have seen this, but Strike Models sells a fiberglass Brooklyn hull.
USS Brooklyn
I know there is a lot of personal satisfaction in building your own hulls, and your doing a great job of it. Just wanted to let you know that there are faster options.

Caleb

 

Haha yeah I saw those, I just thought that building from scratch would be more fun (just waiting for fun to become excruciating pain)

 

Looks like you are off to a great start, I'm very interested to see this progress.

 

So as I said before, I was just waiting for fun to turn into excruciating pain, the second part (bottom of the stack) had a bad bonding in the last 4 layers so it peeled off, of course I didn't notice it until after I had pulled it from the printer so there was no way for me correct it. That's 4 hours down the drain but luckily only $1.50 in plastic, reprinting it now. I hope to have the schematics for my ship side electronics done tonight and, if I am extremely fortunate, I will post pictured of the board file as well.

 

Sounds interesting. What sort of special features are you planning on for the controller? There are a lot of cool things you could do for big gun in terms of automation and targeting that would be pretty cool.

 

I am planning to have several items (going to design the board to have them but it will be limited by my ability to program it of course):
On the ship side:
It will be a dual processor system (one will handle ship movement and the wireless connection, the other will manage the 5 guns)
Throttle mixing to allow for rudder steering as well as propeller tank drive steering.
An accelerometer and gyro to help me dial back my system to keep within legal speeds (but of course I first have to find out how fast this thing can go when over powered)
A real time clock to let me push the allowed shooting speeds to their allowed limits
Individual solenoids for each turret to allow for deadzones as well as staggered firing
Water sensors to detect how high the water is in the ship (Hopefully to help me run when I am taking on too much water)
Air pressure sensor to allow me to only fire the guns when the expansion chamber has recovered
I will also be breaking out the extra pins that I don't use just in case I come up with anything to add to the board.


On the controller side:
Knob based turret positioning to allow me to see how the guns are pointed in relationship to the deck
Digital Read outs for:
Gun angle
Battery voltage
Water levels

I am pretty sure I am leaving something out but, I am open to suggestions.

 

So I am about to shoot myself. I thought I was printing the next section in the stack, but as it turns out I was reprinting the second section. Due to a change in my working hours, my progress has slowed significantly. I have however began to make progress on my control system. I have most of the turret control schematic completed.

I am going to try to finish the schematic and board design by the end of the week and etch it the next.

 

Yeah I am actually mid way through the process of designing the ship side board, and unless I step way from dual Atmega328P (arduino pro mini knockoffs to be exact) processing, I will likely run out of pins to do all of the things I want. I also ran pricing on pressure sensors and unless I build one from scratch using a magnet and hall it is not happening. I also leaning towards moving the servo control boards onto my ship board because I want the electronics (minus motors) to come out in one go.

*Also as an update, 3D printing has not progressed since my original update. My printer needs some love (Thank you GEEETech for "high" quality printed parts, hopefully my printer lives long enough to print my replacement parts). I go back to college in a few days so progress should pick up for 3D printing, but slow down for electronics.

 

So I finally got settled into my dorm, with the plans hung on the wall I continued to make progress on the cad files for printing.
I am still struggling with the bow and stern shapes. I may end up carving them from rough blocks of plastic. My brother and I have decided that the ships must be launched by early July. I am hoping to have a powered hull by December but we will see how that goes. We are also having issues deciding if we will do big gun or fast gun. I am already planning to may the system fully modular so making the ship compatible with both classes is not off the table. As for the control boards. I can't make up my mind on what features I want so I am designing the board in several parts: I am planning to make it so I can drop the board into different ships so I want it as expandable as possible.

Motherboard: Handles signal mixing and manages subsystems

Fire Control Board: Handles guns, will have multiple versions to accommodate rotating and fixed guns and different turret counts

Motor Control Board: Two main versions, brushed and brushless. Brushed will feature its own motor controller and Brushless will feed pwm and power to comercial ESCs.

All of these boards will have current feedback just to ensure that my system can protect itself as much as it possibly can. I know it seems totally overkill, but I plan to design once and program once and have it function on multiple ships. Plus as an Electrical Engineering student I can't resist the urge.

 

for forming the bow of the Shimakaze I used a follow me loft with a guide that was drawn. didn't get it quite perfect but got it good enough.

 

Yeah I was thinking that except mine seems to have a keel that pokes through so loft is giving me issues, I am about 2 hours in on the stern and think I got something.

 

So after roughly 12 hours of work I finally have something to show for it.



The bow and stern are finished. Now I can finish printing the sections and designing the control board.

 

I began working on the turrets again. I plan to use MXL timing belts for turning due to cost, but I couldn't find a good place to get cads files of the different pulleys from. I ended up generating two files to assist me with creating the pulleys for my printer. I figured it might help others in the same situation if I uploaded them. Anyway the files can be found here: https://www.dropbox.com/sh/vy15sfk2ddpqzxy/AAC6tnSpv60nxi94gCr-MaTua?dl=0
These files are in Autodesk Inventor 2016 Pro Student Edition (Let the flaming begin), so I figured I needed to defend myself. I use it because it is free even when you aren't a student. The files just carry a watermark that denotes them as student files. My highschool also used it extensively so I figured why not. especially because I am not a mechanical engineer so a new cad software isn't needed.
On another note I should have my progress uploaded later tonight.

 

Its been a while since I have updated this project. It has actually took a turn for the worse, between my 3D printer refusing to print pieces (due in part to me pushing its maximum print area) and a few cad issues. I have gone back to the drawing board on how I am going to print this project. In the mean time I have begun working on my ship side controller. I currently am testing the code side by emulating the components with multiple boards. It looks kinda bad (I have 3 boards connected together right now to debug the code running on one of them). On the bright side it seems my 3D printer is back to being functional. I decided to scrap my older cad files to get a render that matched the plans more closely. It was close before but this time I think i got the stern and bow a lot better. To improve my success with the 3d printer I have shrunk the part size; every 6 inches of hull are now 3 pieces. Hopefully it pays off. I currently only have the bow printed but so far so good.

So far I have the sections cut up into top and bottom, left and right, there is also a divide in roughly the center of the ship in which i had to enlarge the size of the lower portion to combat some issues I had with the keel protrusion in the rear.


Also, I am curious. Does anyone know of a good way to build a big gun without the use of the ball valve? I was just thinking maybe doing a poppet valve and actuating it by ramming it with a solenoid.
Oh and another question:
I noticed a lot of people use 6 channel radios. I am wondering how they do their control setup. I assume ch1 and 2 and for ship movement and ch5,6 are for firing, but what are ch3,4 use for? if at all.

 

Technically it's not a ball valve, it's a giant air-actuated poppet valve. We call them buna-ball valves because they use buna-N rubber balls as part of the operating mechanism, and most people shorten this even further to "ball valve". The size is necessary to meet airflow requirements, and the air actuation is the only mechanism that has both the strength and speed to operate the valve. People have tried servos, but those were too slow and didn't provide an effective pulse of air. I also saw someone try a solenoid acting on the button for the valve, but it was totally inadequate to overcome the air pressure holding the valve shut. That said, there are a few alternatives. Specifically, take a look at the Quick Exhaust Valve, or QEV. These are mechanically simple, and have a much faster response time than the buna-ball poppet valves we normally use. The downside is that the QEV operates on the negative-gas principle, meaning it fires when you vent gas from the fill port. Unless you take extra precautions when plumbing your ship (and associated extra leak/failure points), it will discharge the cannons every time you flip the safety switch.

There are a few commercially available QEVs on the market that provide sufficient airflow for two-barrel and even some three-barrel cannons. I have not kept up with them for years, though, so I don't know any current suppliers, links, or examples. Other people on this site have used them, however. I have also seen designs for a custom-built QEV that is more compact than the standard buna-ball valve but has the same shape and improved performance. Again, there are sketches on this website but I haven't seen the designer for ages.

As for ship control, the traditional six-channel radio layout is something like this:
left stick: throttle + rudder. Maneuvering controls.
right stick: turret rotation (L/R) + firing (F/B)
dial: elevation/depression mechanism (if used)
switch: manual pump control (if used)
This is based on the old standard Hitec and Futaba setups. Some captains preferred to maneuver with the right stick and aim/fire with the left. I stuck with left stick for maneuvering because that side also had my pump switch. All non-combat controls with one hand, and all weapons controls with the other hand. That helped me, but other people chose different arrangements. It's all up to personal preference.

 

Hey so I was thinking I would build to match the rules ran by SCRAP but I keep googling and I haven't been able to find what rules they use. Can anyone help me out with a link to their rule book possibly? Trying to make this ship conform to big gun and fast gun rules so I can run either or. I understand of course that my guns will have to swapped entirely between the two but I figure the hull at least can be made to fit both. Thanks in advance.