Treaty USS Hawaii

Discussion in 'From Stem to Stern: Warships In Detail' started by rcengr, Nov 13, 2015.

  1. rcengr

    rcengr Vendor

    Joined:
    Feb 13, 2010
    Posts:
    1,176
    Location:
    Ohio
    USS Hawaii, CB-3

    Alaska class large cruiser, launched 3 Nov 1945, never completed.
    29779 Tons, 809' LOA, 91' Beam, 35 knots, 9x 12" guns, 4 shafts, 1 rudder

    Hawaii.jpg

    Treaty Stats:
    Classified as a battlecruiser
    Allowed 3 side mounts, two on one side if in separate turrets, all quadrants can be covered
    Speed: 25 seconds/100'
    Units: 4.5
    Displacement: 22.34 - 25.70 pounds
    Rudder: 3.75 sqin
    Pump: 0.75 or 1.0 gallons / minute

    Units as configured:
    1.5 unit (75 rounds) side mount in A Turret
    1.5 unit side mount in B Turret
    1.0 unit side mount in C Turret
    0.5 unit 0.75 gpm pump

    Hull

    The Hawaii is made from a fiberglass hull, originally cut for fast gun. I'm at least the fourth owner of the hull. The hull is set up with 1/4" ribs, 2" bow hard area and a 1" stern hard area.

    One of the main differences of Treaty is that is requires lower powered guns. Each gun is tested against 2" foam. To pass the test, the BB must not penetrate through the foam. This allows Treaty ships to be built with lighter structures and no rib reinforcement is necessary. However, without rib reinforcements, the internal armor tends to lay right against the balsa side, which is a problem. So I printed some standoffs with my 3D printer to keep the armor a reasonable distance from the sides. In this picture you can also see the 4-40 bolts with two nuts on the ribs to hold the armor in place. While I did not put these in myself, I have found they work very well, allowing the armor to be secured in place but also removed easily.

    armor standoffs.jpg

    The internal armor is made from shower plan liner. It is very durable and stops all the BBs easily. If you look closely at the picture, you can see the bolts sticking through that are used to align and hold the armor in place. I like to remove the armor after each weekend of battling, remove all the BBs behind it, and allow the balsa to dry before I put the ship away.

    Armor.jpg

    One of the things I do with most of my ships is to use 1/4" diameter by 1/16" thick neodymium magnets to hold the decks on. Fortunately when I got this ship, the decks were pretty rotten. So when I replaced the decks I put in the magnets. In this picture you can see the magnets for the bow deck. Magnets are also used in the center section under the main superstructure. I do have two thumb screws in each of the deck sections with guns - that way firing the guns will never displace the decks. To keep a good seal with magnets you do need to seal the decks very well so they will not warp. I use West Systems Epoxy and always seal both sides at the same time.

    Deck magnets.jpg

    The deck still sits flush and gives a good seal after two years of battling.

    Bow deck.jpg
     
    Panzer likes this.
  2. rcengr

    rcengr Vendor

    Joined:
    Feb 13, 2010
    Posts:
    1,176
    Location:
    Ohio
    Electrical Power & Controls

    One of the things I do for new ships is draw out the electrical, control, and CO2 systems before I start building. A little unusual, but I'm an engineer and like to figure out all my requirements up front. This also allows me to see where I can consolidate wiring, put components for minimum wire and hose runs and also determine what components I need to buy. The more complex the ship, the more this preparation helps with the build.

    These diagrams for the Hawaii were put together just for this article to show how it works. While I use PowerPoint for my drawings, a hand drawn diagram will work just as well. I also usually put them all in one drawing, but I have separated them here for clarity.

    First is the electrical setup. In the Hawaii I have two battery systems, one for the solenoids and one for everything else. For Treaty ships in general, the lower speeds, lower pumping requirements, and the ability to change batteries after every sortie mean that large and expensive batteries are not needed. I picked up two 3.3 volt 10Ahr Lithium Iron Phosphate (LIFE) batteries second hand for this ship. The batteries allow me to battle for an entire weekend without recharging. The second battery is a 3 cell Lithium Polymer (LIPO) battery to power the 12V solenoids. This battery is seriously oversized for my application, I would not need to charge this one more than once a year based on the power used. Normally I would use a voltage booster for the solenoids instead of a second battery. However, I put this battery in place to make my first battle with the ship and have never found the motivation to replace it.

    The electrical diagram also shows all the connections to the battery. In the case of the Hawaii, I run 3 Electronic Speed Controls (ESCs) so each had to be individually hooked to the main battery. Note that I only use the Battery Eliminator Circuit (BEC) on one of the ESCs to power the radio. The center wire for the other ESCs is pulled to prevent the BECs from competing with each other.

    electrical.png

    The control setup for the Hawaii is pretty simple. The diagram shows the need for one Y harness and also documents the mix I use for the guns. Because I essentially only have two gun controls, I set them up to activate when I push the stick forward or back, and also when I push it left or right. So the bow guns fire if I push the stick forward or if I push the stick to the right. The stern gun fires if I push the stick down or if I push it left. A couple of simple mixes means that regardless whether I'm thinking bow/stern gun or starboard/port the correct gun still fires.

    Controls.png

    Below you can see the center section of the ship, where all the control runs are. Using wire loom to bundle and protect the wiring makes the ship cleaner. The main items are as follows:

    1) 2-cell 6.6 LIFE battery. Note the Velcro strap around it - this prevents the battery from leaving the ship if it sinks.
    2) 3-cell 11.1 LIPO battery for the solenoids.
    3) Electric switch for the forward solenoids. This is a homemade job that is programed to give a continuous 2 shots per second (Treaty maximum fire rate) when the stick is held down. It also prevents me from exceeding 1 shot every 500 milliseconds if I cycle the stick too quickly.
    4) Waterproof radio receiver. One thing you will notice is that all of my components are individually waterproofed instead of putting them in a waterproof box. The waterproofing of the receiver is done by putting it in a silicone mold and using two-part polyurethane to encase it.
    5) ESC for the port brushless motor. Each brushless motor requires a separate ESC, unlike brushed motors which can use one ESC for multiple motors. My ESCs were encased in epoxy and the heat sink added back on to help keep them cool. http://www.hobbyking.com/hobbyking/store/__14630__Turnigy_TrackStar_25A_1_18th_Scale_Brushless_Car_ESC.html The only thing I don't like about this ESC is that it has a low PWM frequency, so the motors have an annoying whine.
    6) Power distribution to the ESCs. This power distribution board is from a different ship so there are two unused plugs. The key point is that each ESC needs to have a separate plug so that it can be disconnected and replaced at the pond if there are any problems.
    7) The ESC for the pump. The pump is also run by a brushless motor, so this is a one-way aircraft ESC.
    8) The starboard motor ESC.
    9) The bilge pump. Big pumps and big pump motors are not necessary in Treaty. I generally use a wide open 1/4" discharge tube and then adjust the ESC to make my allowed pumping rate.
    10) The plug to the stern gun solenoid. As with the ESCs, it is important to have plugs throughout the electrical system so that you can remove and replace components without soldering. The plug used here is a non-polarized mini-Deans plug. I use these plugs for pretty much anything that uses less than 10 amps. The plugs for the main battery are Anderson Power Poles and plug for the solenoid battery is a standard Deans. I care enough pigtails in my radio box to convert from any plug to any other plug.

    batteries and controls.jpg

    The battery tray has some braces on the sides to make sure that the battery cannot move back and forth. This is also a good picture to show how I use self-leveling concrete sealer. Not only does it give a nice flat surface over the water channel fill, it can also be painted on any surface to give a thick rubbery protective coating. Now if I could just figure out how to get rid of the rust stains from the BBs, it would look really sharp.

    Battery tray.jpg

    The rudder servo set up is pretty simple. The rudder servo is waterproofed by disassembling the servo and coating the control board with Liquid Tape or Scotch Kote and then also coating the outside. Two pushrods are used to prevent the rudder from overturning and getting jammed. One of the pushrods is kept slightly loose to prevent binding. I like this picture because it shows just how much room is in this ship.

    rudder servo.jpg
     
    Panzer likes this.
  3. rcengr

    rcengr Vendor

    Joined:
    Feb 13, 2010
    Posts:
    1,176
    Location:
    Ohio
    CO2 system & guns

    The CO2 system is pretty simple. Note that I put all the adapters and nipples in the drawing, this will prevent you from having to make multiple orders to get those parts you forgot. I used 1/8" hose to get CO2 to the solenoids and then 1/16" hose to the guns. Because of Treaty's slower firing rate and lower BB velocities, I could really get by with 1/16" hose throughout, relying on the accumulators at each gun to make sure they are not starved when fired.

    CO2.png

    This is the front set of guns and solenoids. The guns are standard coil guns from either BC or Strike. The large barbette of the Hawaii means that the guns are easy to mount. Both of these solenoids are set to fire together, so to test and tweak just one gun I block the 1/16" hose for the other gun with a surgical clamp.

    Guns and solenoids.jpg

    The bow guns and turret covers. The bow guns are set up to hit at the same place, approximately 3' from the ship. Note the two screws sticking up in the middle of the deck between the guns. Nuts on these screws keep the guns solidly mounted yet allow the deck to be removed pretty quickly for servicing.

    Bow guns.jpg

    The stern gun is about the same, but fires off the opposite side of the ship from the bow guns. I should really mount the solenoid, but I have so much room in the ship that I just throw it in and let it rest on the bottom.

    stern gun.jpg

    This is the gun mount I use. It works great on ships with big barbettes, but is harder to use in smaller ships. There is base that is bolted through the front of the barbette. On top of that is the elevation plate which can be adjusted to get the desired range by moving two set screws up and down. The last part is the brass strap which solidly holds everything together. The up tube of the gun is held to the back of the barbette with a zip tie, making for a very solid mount. I have had these mounts crack occasionally, but mostly they hold up to some very heavy abuse, including direct contact with other ships - all without the gun moving out of position. And the entire mount fits within the barbette, so the turrets fit right and the ship looks more scale... something I try to do on all my ships.

    I also have 1/4" ID vinyl tubing over the barrel to prevent BB dings. Even with that protection, I carry a 3/16" reamer in my toolbox to fix any dings that may occur. As with most of the fast gun rules, Treaty requires a pin in the gun barrel whenever the ship is out of the water. My pins are captured with fishing line, which also secures the turret cover in case it is shot off.

    gun mount.jpg

    The CO2 bottle is mounted all by itself in the forward center section. A simple plywood yoke keeps it aligned right and some Velcro makes sure it doesn't shift.

    Bottle mount.jpg
     
    Sethie and Panzer like this.
  4. rcengr

    rcengr Vendor

    Joined:
    Feb 13, 2010
    Posts:
    1,176
    Location:
    Ohio
    Propulsion

    For drive motors I'm using 28mm, 750kv, brushless motors. http://www.hobbyking.com/hobbyking/store/__12922__Turnigy_D2836_11_750KV_Brushless_Outrunner_Motor.html This setup works well on the Hawaii, having very low amperage draw (<2 amps IIRC) and is very responsive. I have to set the ESC at 90% to make speed, so I even have a little bit of headroom left over. The motors are connected through standard dog bones to the drive shafts. I do recommend that you grind a flat on both the motor shaft and the drive shaft for the dog bone setscrews to engage. In my first battle I had a dog bone that was slipping, causing a drastic reduction in speed. The problem was hard to diagnose (everything worked great when out of the water) but was an easy fix once I realized what was happening.

    The motor mounts are CNC machined from fiberglass plate. You do need to think ahead when planning mounts for brushless motors, since you need to allow the outer case to rotate freely.

    Brushless motors.jpg

    I'm using 1.75" props on the Hawaii. As is allowed in most fast gun formats, only the inner shafts are driven and the outer shafts have drag props on them. With a single rudder, the center skeg, and the long length, the Hawaii doesn't really turn well. You always need to be planning ahead in combat.

    Props.jpg

    Auxiliary Systems

    Another important system, a system I need to install in more of my ships, is the recovery float. As a minimum, the float needs to deploy to show where the ship sank. A better system is a float that is solidly attached to the ship so that you can use the line to pull the ship up from the paddle boat. The Hawaii has a float line that attaches to an eyelet under the deck, allowing the whole boat to be pulled up with it. By having a clip on the line, it can be removed and the superstructure separated from the rest of the ship for transport or maintenance. The 20' (our ponds are up to 12' deep) of recovery line is stored in a small box under the deck. The box is held on by magnets and can be easily removed to re-coil the line. The box keeps the line protected from inadvertent snags while you are working on the ship.

    Float.jpg

    The superstructure is made of light weight foam. So the float is just the rear stack that is free to float up if the ship goes underwater. The wood dowels not only keep the stack aligned on the superstructure, they are also long enough that a couple of hits will not knock the stack off during a battle.

    Float 2.jpg
     
  5. NickMyers

    NickMyers Admin RCWC Staff

    Joined:
    Nov 15, 2007
    Posts:
    4,347
    Location:
    Federal Way, WA
    I really like this and am going to have to replicate it.
     
  6. NASAAN101

    NASAAN101 Well-Known Member

    Joined:
    Aug 26, 2009
    Posts:
    2,315
    Location:
    Pittsburgh PA, USA
    Little Hawaii. She's a great ship.
    Nikki
     
  7. dietzer

    dietzer Admiral (Supporter)

    Joined:
    Mar 27, 2007
    Posts:
    716
    Awesome job, Mark!

    One question -- how did you mate the 12g disposable cartridge to the T-fitting?
     
  8. rcengr

    rcengr Vendor

    Joined:
    Feb 13, 2010
    Posts:
    1,176
    Location:
    Ohio
    If you carefully remove the pierced membrane from a spent cartridge, the hole is the right size to tap 10-32. Then all you need is a Clippard 10-32 male-male fitting.
     
    Tugboat likes this.
  9. dietzer

    dietzer Admiral (Supporter)

    Joined:
    Mar 27, 2007
    Posts:
    716
    Clever!
     
  10. NASAAN101

    NASAAN101 Well-Known Member

    Joined:
    Aug 26, 2009
    Posts:
    2,315
    Location:
    Pittsburgh PA, USA
    Mark, that float, would somethink like that work on the Destroyer?
     
  11. battleship_dave

    battleship_dave Member

    Joined:
    Dec 30, 2007
    Posts:
    22
    alaska8.JPG alaska13.JPG sept24.JPG alaska7.JPG alaska5.JPG alaska6.JPG alaska 14.JPG Alaska Mold 1.JPG Alaska Mold 2.JPG Alaska Mold 3.JPG Hi
    I saw this post and wanted to show some photos of the plug being built.
     

    Attached Files:

  12. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

    Joined:
    Jan 10, 2007
    Posts:
    8,292
    Location:
    Statesboro, GA
    Another Alaska mold? Ay caramba! Or are those pics of the original?
     
  13. battleship_dave

    battleship_dave Member

    Joined:
    Dec 30, 2007
    Posts:
    22
    That is the original and the Hawaii shown above is the first hull to be made from the mold that I made.
     
    froggyfrenchman likes this.