A number of design choices have put me in the predicament that I find myself in. First being the way I filled the voids between the ribs in the hull, I should have cut down into the ribs more and created recesses for certain pieces of Hardware like the batteries. That would have gotten that weight lower and also would have made the boat overall lighter because it would have taken less filler material. Second would be my choice of filler material. The concrete sealer worked well but is on the heavy side. Due to the height of the voids I was filling I ended up using a lot, I want to say something like two or three of the large caulk gun tubes. That added a lot of weight. This weight is low in the hull which is good, but the boat is right at max weight right now so I would have rather had wiggle room. Third is the superstructure. The 3D printed superstructure added a bunch of topside weight and while the detail is very nice and makes the boat look gorgeous on the pond it's not helping the Tipping situation. I played with the files in Cura and think I can cut the weight by about a third. I'm starting production on the new lighter SS now. Finally, my gun mounting and construction. I put the forward deck hatch on a food scale and with the turrets on it clocks in at 7lb pretty much even. All the weight of the copper accumulator tanks check valves and solenoids cannot be helping the instability. However I'm extremely satisfied with the gun performance and I'm not planning on messing with them too much. I would rather chisel out the filler in the bottom of the hull, and I'm also not gonna do that.
Yeah.... I ran into the same exact problem with concrete filler in Texas. I'm going to do something interesting with Idaho to avoid that, hopefully it'll be a good idea for future endeavors.
Short term working on the SS is your best bet. If you really want to help stability, make most of the SS out of plastic stock and allow it to get shot up. The more they blast off, the lighter the ship gets (win/win). Concrete sealer, remember that well back in "the day". Same issue, just not easy to adjust weight. If you want to drop some of it without excessive chiseling, remove it from the bottom of the hull. Drill holes in each corner, and remove with jigsaw or drywall saw blade. You could do every other rib and then just glass the bottom of the hull. Fill with balsa and go. Wouldn't blame you one bit if you waited for winter refit.
Now that's an idea, I like the thought of just removing it from the bottom. I will put that away for the future. My previous wooden hull adventures (Dunkerque and Suffren) both used blue lowes foam between the ribs and required excessive ballasting. I think I added 13lb to Dunkerque to get her near her waterline. I figured I'd have weight to spare on a 43lb canoe, looks can be deceiving haha. I am working on the v2 superstructure to remove topside weight, what I take out I will add to the center 2 bilge keels in lead. The outer 2 bilge keels I will keep as wood, I want to keep the weight along the centerline. Edit: Small update doesn't deserve a new post. Looks like my early estimates of 1/3rd the SS weight are a little conservative, I can get it about half the current weight judging by what Cura is telling me and how light the first few prints are. I doubt it will be very durable, but I'm willing to deal with that to solve the tippy issues.
Foam in the bottom has its own issues. When water starts to accumulate in the hull, you have heavy (water) on top of light and that can cause instability. Finding that material that will be dense enough but light can be a challenge, and that changes with each type of boat. In the past years I saw a lot of well performing wooden boats that only have 1/4 inch water channeling, and they used the internal components as water channel "walls" that would direct the water to the center.
I was originally planning on using featherlite, maybe this winter I'll do a bottom-out refit and cut away the concrete sealer and use featherlite. What's worth doing is worth doing over, right?
It seems like there are a few different types of concrete sealer. What I used isn't very "gooey" it is a hard polyurethane. I wouldn't have minded it if I used less of it, it worked well actually. But I used a lot of it, thinking I was adding weight where it should be, and now could use a little more wiggle room in the ballast department. I'm not super concerned about the sealer. I'm taking weight off the top, adding it to the bilge keels, and once the boat is running it's actual legal speed I should be set. If necessary, I can try cutting out sections from below like @Lou mentioned above. I don't think it will be a problem though.
Made the two center bilge keeps from lead today. Each one was roughly 2lb. I'll have saved about 3 lb with the lighter superstructure and had four lb to play with before I hit max weight, so we will see how this helps the boat. Also got my HobbyKing order in with 3 amp hour 7.4 receiver packs to help the solenoids operate more reliably and 2200 KV 28 by 26 mm brushless motors for the pumps to replace the motors that burnt out. These are Turnigy aerodrive which are on the cheaper side of the price range but had good max power output in terms of wattage and were the only ones I could find at the correct KV rating in the size I wanted in stock. The only issue was the shaft came out the wrong side. On these motors it was as simple as loosening the set screw and putting them in a vice with a socket on the other end to leave a void for the shaft to go into. Voila, shaft comes out the proper side. Added some Loctite to the set screw tighten it back up and now I've got two fresh pumps to go in the boat.
After Action Report for Ming's Moat battle 5/17-5/19: Bart did pretty well this past weekend at Ming's. Had some small technical issues Friday and saturday morning. First was pump related. Boat sank Friday due to the new pumps literally being assembled Thursday night and lacking screening. Whoops. Screen your gerdam pumps! Main pump sucked up a bunch of balsa, turned it into paste, and clogged the restrictor. Cleaned that all out and applied screening material to both pumps. Auxiliary pump did its best but with it's location in the bow area and the fact that it was spinning backwards, Bart ended up on the bottom. My next issue was with my Hobbyking X-Car 120A esc's. They use an on/off switch with a reset button, so 3 wires for the switch. I wasn't sure how to bypass the switch/button setup since I had only ever worked with simple on/off switch ESC's in the past. My drive ESCs started to freak out Friday afternoon, and with Carl and Nate's help I removed the switch and on/off button. After these relatively small hiccups, the boat had no real issues. The lead bilge keels helped a lot in stabilizing her, as did bringing her down to her actual speed of 24 sec. Still trying to get her to accelerate a bit better, turn a bit better, but the general consensus is that she turns pretty acceptably for a 68" long 43lb single rudder log. New 5 bladed kort nozzle props from Protean Design (New Prop Shop) are on their way, hope I can get them on the boat before Nate's battle June 7-9 along with a new rudder. The new props are set up for an m5 metric thread, so they will be riding on new 5mm diameter stainless shafts. This is a very convenient size prop shaft to use if you can fit them as the RC racecar/offroad hobbies usually use 5mm bore for their gears. 5mm shafts means you can use these common gears without any sort of adapting. I planned for this from the start and my stuffing tubes are set up to have the old 4mm shaft bushings pulled out and new 5mm shaft bushings pressed in. Not much work needs to be done at this point. I've cleaned up some wiring runs, loomed some stuff, made some very minor improvements. Damage pics. Lots of paper used to patch lots of holes. If I had sheeted the ship without this titebond method it would have holed a little bit better, not causing large cracks that require 4" strips to cover up.
After Action Report 6/7-6/9 Battle Bradford, PA: So the new props from Protean did arrive in time, just barely. I had a hiccup trying to mount them but ultimately got them in the boat with a hastily constructed new rudder in time for Nate's battle. As shown in the picture below, I mounted them in the traditional "tops turn in" fashion which I will comment on later: All weekend the boat performed very well. Only major issue I had was with the new shafts trying to walk out of the boat, which was solved with more aggressively flat-spotting the shafts and Incredible Hulk-ing the set screws. The first few battles, however, the boat's stopping and reversing ability was relatively lackluster. I was at 80% endpoint forward to make speed and even at 120% reverse it took at least 10+ seconds to come to a complete stop, let alone reverse. As a test while reinstalling the prop shafts, I decided to swap them side for side to the "tops turn out" orientation. This resulted in a whole new boat. I needed to drop endpoints down to 30% to make speed, and the boat would go from 24 seconds max speed to stopped in a boat length. No real noticeable difference in turning performance. All in all the boat performed well. Need to drop the B turret guns and play with them a bit, they started to function well by 2nd battle Saturday but I want to get them adjusted better before NATs. A turret guns were the superstars of the weekend, responsible for putting large numbers of holes in USS Washington driven by Kas and Viribus Unitis driven by Brandon Graham, resulting in both of them going under. JB came out of each battle with roughly 950~ pts in damage give or take a few and shorts stayed dry this weekend. Bart in Drydock at the Graham shipyards for post-battle maintenance: Some damage. Almost like this boat wants to be trading sides in this area... Caught USS Washington by her stern starboard quarter and she couldn't maneuver away which led to her staying under A turrets guns longer than her captain would've liked, I'm sure! This whole area was essentially mush after this sortie and she went under. Now it's time to start prepping for NATs. Boat needs new sheeting and some small hull tweaks regarding her impenetrable area (the raised center deck area can be impenetrable to the level of the subdeck) and number of ribs (too few currently). I've already stripped the old sheeting off to help dry her out, will start the refitting process probably tomorrow.
Did a little Bart work today. Got the new impenetrable area built on one side. I blended this into the ribs/subdeck, so balsa can be applied directly over it instead of having an unsupported top where the balsa met the impenetrable. Also brought it down 3/8" so it was even with the bottom of the subdeck, where it should have been from the start.
Very minor update. Just wanted to post some SS damage pics. Its very strange how certain areas of the ship take damage far better than others. Not sure if its water absorption into the filament or what, but look at the difference between the B turret barbette which has dozens of dents and the main superstructure tower which shattered. Very odd. Some gun directors were shot off and not found, but I was able to keep the secondary and tertiary batteries in place. Going to replace all the real busted stuff before NATs, because that's the important part of the boat. Gotta look good.
More NATS prep. Bart and Suffren getting some sheeting done and new paint. Not too sure on Suffren's waterline here. Haven't had a chance to float the model yet. I aimed for a scale waterline...can always slap more red on it later
It has been a while since I posted. Life post-nats has been hectic and I thought I'd have at least 1 fall battle to report on. Turns out, Nats was my last battle for 2019. Jean Bart was my "Rookie Boat" despite having been around the hobby for some time, and with it I won both the Swiss Cheese award (most damage resulting in a sink) and the Rookie of the Year award. Jean Bart over the course of 2019 proved that history is just something you read in a book. She had her fair share of teething issues and maintenance problems, but with all systems functioning she was a strong presence on the water capable of taking tons of punishment and dealing out damage just as good. Jean Bart worked best when paired with 1, sometimes 2, smaller more maneuverable allied battleships to prevent hostile battleships from under-running her guns or trapping her in a swarm. She does turn "acceptably" for a ship her length, but she isn't agile enough to sit in the middle of the furball and if I found myself in that situation I needed to immediately retreat (as per French doctrine) or I would take a serious beating. She does have the speed and the bulk to serve as an extremely effective large angry wall, a task she was called upon to perform a number of times at NATs to pin isolated axis ships so smaller units could finish them off. In one memorable instance Jean Bart, with USS Arizona sailing as her wingman, ended up attracting the attention of no less than 4 enemy battleships. Jean Bart's bulk created a shield for Arizona to effectively engage 1 of the hostile ships and sink it, while the other 3 jockeyed for positioning to get shots in on Bart or get around her to engage Arizona and relieve their beleaguered comrade. When we realized that we had bought our team enough time "being the bait" to sink a number of Axis ships and with gun magazines running low, we made the decision as a pair to call 5 and retreat from the Japanese straight through the main fight. Jean Bart's size forced the enemy ships out of the way while Arizona followed, with 'Zona almost getting trapped by the remaining 3 enemy BBs only to have Bart clear the way by backing through the enemy ships to open a path. I did have some maintenance troubles, mainly related to the bearings on the main shafts of my brushless pump motors. Two pump motors failed due to bearing failure, which has now added another pre-battle maintenance check to my list. Buy replacement bearings, change them out at least once a season. Keep them oiled! Brushless motors may not make the horrible sounds brushed motors do when they need oil, so don't wait for them to warn you. I also had an issue with one of my propellers coming loose twice, despite having red-loctited them on. I believe that this was mainly operator error, as the first time the prop came off it had managed to almost saw through a 2" diameter tree branch underwater before my constant forward-reverse throttle changes unscrewed it and left it embedded in the wood. The second time I did not give the loctite sufficient drying time, and I had applied it with the shaft and prop still damp. The other propeller had no issues and is still to this day very firmly attached. Jean Bart's guns, my first ever designed and built by me, worked with no issues. B turrets gun barrel breech sleeves are not quite long enough, as a result B turret's guns were always a bit under-tweaked. That was easily fixed temporarily by sliding a compression fitting ferrule over the barrel under the breech nut at NATs. I did have some issues with the Combat Gear solenoids I had used on the boat, but with @Charley present at the battle I had instantaneous tech support to get me going again with two fresh solenoid coils. The only other issue is actually the biggest one of all: Jean Bart is actually overweight. I had interpreted the rules wrong in the section for maximum weight. It stated that you were allowed 10% over the heavy weight listed on the ship list. I assumed this meant I was allowed 40.4lb + 10%, leaving me at a max weight of 44.44lb. This was incorrect; the ship list max weight takes this 10% extra into account already. So I'm currently a whole 3.5lb over legal weight. I have already begun the slimming of the ship, with newer lighter weight superstructure on the build plan for this winter. Should this not be sufficient, I have a large surplus of battery power onboard and can halve the current battery load to make up the rest. Woah. What can I say. This has been a wild ride. I have been around the hobby for 7 years but this was my first real battling season and my first ever NATs. This was the first time I gave the boat the attention it needed to be even somewhat successful. I hope to continue to update this build thread with my future JB efforts including the lighter weight superstructure and her adventures on the water for years to come, but for now, the construction aspect of this ship can be considered done. Though I do plan to bring JB to every 2020 event, she may take a back seat as I build my Courbet this winter and battle it as my primary ship in 2020. That will bring my French squadron to a finale. Vive la Marine Nationale. Honhonhonhonhon.
So, with the coronavirus shutting a bunch of stuff down and me working from home, I've suddenly found a lot of time to work on boats. Of my Spring 2020 boat projects, a medium level refit of Bart is in order. Goals are: Reduce Weight (44lbs currently, max weight per rules is 40.4) specifically reduce topside weight Replace all brushless motor bushings Re-certify all guns are operating properly Possibly experiment with moving bottle and forward pump to create more clearance between gun deck and aux pump motor. It's a bit tight now, with the gun accumulator tanks resting on the brushless pump motor shield. Address propeller retainment (Considering brazing the screws onto the shafts. Change my mind?) To achieve these goals, I started with my original 3d model I made for the hull. I started modeling the upper works of the boat, the goal being a CNC cut foam superstructure that would be extremely light weight. To achieve this, the main superstructure blocks are not detailed at all. I then re-modeled all the secondaries, tertiaries, quaterinaries, their associated directors and radars, etc so that they could be printed and made into silicone molds for lightweight foam copies. Here are some pics that are also shared in my 3d design tutorial: And here is a pic of my first foamy 2.2" dual AA turret: The difference in weight is astounding. It is essentially weightless, my postal scale wouldn't read it at all.
Brazing worked well for Agincourt, just don’t melt the prop (seeing it glow is neat though) I second the notion of more clearance for the forward pump- some things you don’t want to be an interference fit. Maybe move the pump before you add the rivets to the quarterineries
Looks good. A lot of the simple superstructure details like portholes and doors can be drawn on with a sharpie and a 3d-printed template.
