This is the documentary of the construction of my IJN Nagato. I plan on detailing her as she was in 1941, when she was the Japanese flagship during the Pearl Harbor attack. I purchased the hull indirectly from Battlers Connection at the Fall 2010 Southeastern IRCWCC Regionals. It was traded to Carl Camuratti several years previously in return for some work, and he returned it to Rick at the regional because he already had a Nagato partially competed. I was impressed by the hull lines, it is easily one of the most complicated and well executed fiberglass hulls I have seen so far. Here is a picture of some of my uncompleted hulls sitting in my mess near the end of 2010. I don't like cleaning up to stage photographs. From the bottom left they are: Swampworks IJN Agano, Battlers Connection IJN Nagato, Battlers Connection DKM Scharnhorst & DKM Gneisenau, Unknown Prinz Eugen, Battlers Connection DKM Z-25, Swampworks FS Glorie, Swampworks KGV, and two Ralph Coles HMS Warspite. I made the plugs for the Agano and the KGV back in 1996. I refer to the original hull source here, the Swampworks hulls are available from Strikemodels now. I expect most of these will eventually be completed by somebody, but I'm going Japanese. We have three battlers in Greensboro now and have fairly regular build sessions in my garage. It definately makes building a lot more fun!
Wow and I thought I had a lot of incompleted ships. I feel better now. I got the Nagato from BC too and it has the main decks in place but that's it right now. Go with a Duke of York. Like to see more out there.
One of the first things on the to do list was acquiring parts for the build. I had previously purchased a couple of 10 oz CO2 tanks from Strike Models, and a few variable regulators. A bottle and a regulator are visible in the picture above, sitting inside the Nagato hull. Next on the list was batteries. I have been using LiFePO4 batteries in my ships since I started battling again in 2010. I really like them. I put a 6.4 volt 3000 mAh pack from Strike Models in both my LSTs when I completed them last year. When I refit the old HMS Invincible at the beginning of 2010 I changed from a 12 volt 7 Amp-hour gel cell to 4 of the flat, stainless steel clad LiFePO4 cells from Strike Models. The gel cell weighed in at 5.5 lbs, all 4 of the LiFePO4 cells together weighed 4 lbs. Its always nice to lose weight, but even better the power available went from approximately 84 Watt-hours with the gel cell to 128 Watt-hours with the LiFePO4 cells. No more running out of power at the end of the second sortie! This performed well through NATS. The problems began with the I-boat after the second refit of 2010, where I replaced the deck and the subdeck with G10, (also called Garrolite, a Epoxy/Fiberglass cloth laminate). This stuff is much denser than wood and I ended up pushing the I-boat's weight well past the max model weight. While looking for ways to reduce the weight, I found I could keep the same amount of power and lose another pound by using 4 * 3.2 volt 10 Amp-hour headway cells, which weigh in at approximately 3.0 pounds. Got them from currentevtech for $19 a cell, plus the orange end brackets to hold them in place. They were good to deal with. While researching LiFePO4 cells at the beginning of 2011I also found that the 3.2 volt 20 Amp-hour cells are extremely scarce. These are what I decided to use in the Nagato. The only way to get them at the beginning of 2011 was in a 4 cell pack designed to replace a 12 volt gel cell. Two places had them, Batteryspace, which wants something like $250 for the pack, and elitepowersolutions, which wanted $120. As of May 2011 they are $124. This is where I ordered them from in February. The 4 cells in a case, minus the top of the case. They are put in the case by a obscure chinese company called GBS. Pulled from the case. They have no identifying marks on the cells, but do have some pencil notations. Two of the GBS cells next to the 4 headway cells used in the Invincible. Theoretically the same amount of power here, the GBS cells are a couple of ounces heavier. The floor tile is 12" on a side. Three of the GBS cells, the turrets, the bottle and regulator in the hull. The cells will fit nicely on both sides of the bottle. The fourth cell is on a charge/discharge/charge cycle at that point to determine its capacity. All 4 cells laid out around the CO2 bottle. Capacity check on the batteries showed the cells were delivered approximately 55% charged. The measured capacities were between 18.5 and 19.2 Amp-hours. Slightly less capacity than I expected, but consistent with what one could expect if they were about 2-3 years old. Assuming the 20 Amp-hour nominal specification was met when they were new. One of the LiFePO4 battery manufacturers in china went bust a couple of years ago, I suspect these are surplus cells from them. That said they are fine for our use! In 7 or 8 years I might replace them with a newer set, but the battery chemistry technology will probably have changed again by then. Please take the time to recycle your lead acid and lithium batteries when they go dead.
When you have been doing this as long as you and I have, Curt, you tend to collect a bit of fiberglass clutter.
Next on the agenda was laying out the ribs. I used the new MWCI stringer rule, since I really couldn't figure out how to sheet the hull around the well defined bulge area without the second stringer. I had not float checked it yet, so the bottom of the windows is unmarked. Casemate coupolas marked off, I found them to be a little bit unevenly formed on the fiberglass hull, so the space at the edge varied. You won't want to park your boat here when I'm done. The next day I did the float test, we had some warm weather for a change. The old gel cells came in handy for something... Near max model weight 32 pounds Under 30 pounds here. 61.5 inches long, 15% hard area is 9.225 inches. It ended up with 26 1/4 inch ribs + 2 inches in the bow + 11/16 inch in the stern = 9.1875 inches of hard area. Close enough. I ended up moving the end of the bulge stringer 1 rib over. Note the deck rim is 3/8 inch tall in the forward part of the ship, but only 1/4 inch tall anywhere there are two stringers. I don't cut the windows until I do a final float test with the props and rudders in place, so I can double check to make sure I have the bottom of the windows right. It is time consuming to redo a hull later. I found the dishing in the bottom of the hull to be at an unacceptable level (3/8 inch tall) while doing the float test, it made it really difficult to get the hull to float level. What to do about the dishing........ In a later post. Thus ended the work on Nagato in February. I had to stop to correct some of the self-inflicted problems with my HMS Invincible in time for the Brouhaha. I didn't get back to it until April.
Skipping to April.... It is difficult to work on your boat when it is full of blocks, trains, ball and boy! I bet it would still float! Notice I have started adding spreader bars and supports for the subdeck to the hull. It was more than an inch too narrow at deck level in the middle. Another good reason to postpone cutting the windows until a second float test is done. It should float a little higher now.
Salvation is near. Repent from your Allied ways! Release your Allied ships and hulls to Davy Jones and complete your Axis Fleet!!! Nagato is a good choice. Looking good! J
Drive and Rudders Went ahead and built a gearbox in the middle of April. I have built 3 for various boats earlier, all have worked well. My I-boat's gearbox is capable of driving all 4 shafts off 1 or 2 motors, initially it was a testbed for active drag props. I only run the two center props on it now with a single motor. This one was less successful than the earlier ones, I meshed the gears togerher too hard to accomodate their manufacturing tolerances, and I had the shafts locked in train so they were forced to rotate at the same rate. It has since been replaced with one that appears identical on the outside, but allows each shaft to spin at its own rate. The gearbox bolts directly to the cross brace just under deck level. The motors in the picture are Titan 21 turn. They are 14.4 volt motors with slightly advanced timing. On 13.2 volts they sound like they will make excellent pump motors, but for drive I am using Titan Marine. They are 23 turn motors, and are supposed to have neutral timing. They are relatively high rpm, and have silver colored brushes. The lowest ratio in my gearbox is 3.2 : 1 so there should be plenty of torque available. Each motor draws 1.6 Amps no load, and connected to the gearbox they draw about 2.0 Amps each at the lowest gear ratio. I haven't tested the amp draw in water yet. The highest ratio available is 1.16 : 1 I mounted the motors facing backwards in the hull relative to the common practice to reduce the ammount of wasted space in the hull. Y turret overlaps the front edge of the gearbox slightly, but the prop shafts are only 6 inches long and run directly into the gearbox. By not running the prop shafts forward under the turrets I gained a lot of vertical space that will be utilized later. I took some old 1.5 inch 30 pitch Battlers Connection props I had laying around and ground them down to 1.125 inches diameter. I also brazed the blades on so I won't lose a blade in the future. I think it gave them a cool shape. Drive and rudders installed loosely in hull. I use flat rudders. I also use a lot of stainless steel. Made some struts for shaft support out of oval tubing and ran 4-40 stainless steel cap screws through the hull to hold it in place. It rigidly holds the stuffing tubes in place. The rivets at the top edge of the ship hold the cross brace and subdeck supports in place. I won't have to worry about subdeck separation, ever. This picture is of the second gearbox with installed Titan Marine motors, as well as the rudder gearing. The big gear on the servo is 66 tooth, the small ones are 28 tooth. Barely visible is the stainless steel bracket I fabricated to hold the servo and rudder stuffing tubes in the correct orientation. I get about 170 degrees of rudder throw with this setup. I also have a sexy big toe. More later...
Ron those pics are great use to me for building my Nagato. Your layout of the ribs is what I would have used as well. I like the cross braces you built. Something I forgot to do for mine before I installed the main deck. I am going to use this build as a reference for my Nagato. I like the way you freed up space behind the motors which is a problem with the Nagato's when installing the motors. Great work!
Towards the end of April I got in two reference books I ordered from Pacific Front Hobbies. These are some of the foldouts that came with them. The one with the color computer graphics is Encyklopedia Okretów Wojennych 52 Nagato,Mutsu vol. 2 by MirosÍaw Skwiot and published by AJ Press. The drawings are the same as the ones in Monografie Morskie 5 Nagato Mutsu published by AJ Press, but the CG renderings are really nice. The other is Super Illustration No. 769 Imperial Japanese Navy Battleship Nagato published by ModelArt. It is full of isometric drawings of sections of the Nagato, and clearly identifies the known differences between the Nagato and Mutsu. It is geared toward the scale model builder, and includes drawings of all the deck fittings. I'm using it as my main reference as to how something should look, but it is not really good for dimensions.
I'm skipping ahead a bit here to where I sealed the cutout around the rudder posts and prop shafts. In this picture you can see I used some two part metal filled epoxy putty to plug the holes. I am almost done shaping the area around the closer stuffing box here. Here I am mostly finished shaping everything.
It is a knock off version of JB Weld. At $2 an ounce even this stuff isn't cheap. It remains to be seen how well it will hold up to combat. I don't really remember how much the books cost but probably $30 to $40 each. Another series of computer graphic books I really like is pubished by Kagero. I believe the series title is Super Drawings in 3D. It is sometimes available pretty cheap from Amazon, but they sold out of quite a few. www.kagero.pl (Polish/English website) They have books on the Kongo, Bismarck, North Carolina and Scharnhorst, plus others. The last one I got was the newly republished Scharnhorst and actualy includes 3D drawings that you need the glasses for (Anaglyph). Way cool.
Nagato Gets Subdecks, Bilge Keels and a Sexy New Bottom In the middle of May I started the subdecks. They are a single layer of 1/16 inch thick G10, and Epoxy/Fiberglass cloth laminate that goes by the trade name Garolite. It is available from McMaster Carr in various thicknesses and colors. It has approximately 2/3 the impact resistance of Lexan, and my testing has shown it takes very little damage from our cannons even at close range. 1/32 inch thick ends up with some white stress marks and a small dimple from a point blank bb hit. 1/16 inch thick shows almost no damage at all. This stuff is nasty to work with. Carbide tools are a must. It will eat normal dremel cutoff wheels in about a minute. The dust is probably toxic and gets absolutely everywhere. I should probably wear a better dust mask, but I do have a fan blowing directly on the area where I am cutting so most of the dust is directed away from me. Shaping it is fairly easy with a carbide cutoff wheel, a belt sander and a bunch of files. The next series of photographs will show my solution to the bowed up bottom, as well as my method for adding bilge keels. I put the hull on a router table with a big flat bit set 1/16" above the table surface and cut into the bottom. Then I trimmed out the center section. Make sure you already have the cross braces in place before doing something like this, the hull is likely to flex. I cleaned up and flattened the top edge of the cutout with a large flat file. Grabbed a piece of threshold vinyl replacement from the local ACE hardeware. Marked the location for the bilge keel. The pieces of 1/4 inch tape are sections I didn't cut out. You can also see some of the overhangs around the casemates at the deck edge. The casemates are not quite the right shape on the hull. I split the edge off the threshold strip. Nice triangle shape, with a tongue on the back side. Then I started stuffing the tongue through the slots I had cut previously. Every 3 inches I left a piece of fiberglass hull intact, if I had cut the slot the whole length of the bilge keel the joint would be able to flex too much. Took about 20 minutes to install each bilge keel. Also note my method for supporting the subdeck. The small blocks are a thicker piece of G10, riveted to the side of the hull. The blocks also have a 4-40 tapped hole in the center for attaching internal armor. A little flexible CA holds it in place nicely. Trimmed the ends at an angle and ran a 5/64 brass tube through the center of the V to help support it. It is pretty soft stuff. I wonder how well it will hold up over time. I already destroyed and replaced it after hitting it with a file while shaping the bottom. Next I roughly trimmed a piece of G10 to match the bottom. Note the small rivets holding it in place while I filed the edge down to match the hull. Almost done shaping it here. Test fitting with a 3/16" diameter rivet every 3 inches. Through all this work I regained about 3/8 of an inch of height in the center inside of the ship, where I may need it for cannon clearance. Not time to install it yet though, some of the later work will go better without the bottom of the boat in the way. Next Installment: Nagato gets Decks
Thanks. I will have to see how well they stand up to the rigors of combat. They are out there right where they can take the occasional prop hit. I expect I may have to replace them with metal later on.
But the brilliance is that it is ease to replace if it does take a prop hit. Just cut a new section and epoxy it in place.
