U.S.S. Illinois has been put in the water at last, and aside from being horribly underweight (she's showing about three-quarter of an inch more than she should be) it was a fantastic test. It started out with a motor positioning issue that was resolved after I lowered the motor on its mounting bracket. After that was dealt with (repeated returns to shore finally fixed the issue for good and all), the ship ran smoothly for the remainder of its test. Some issues discovered at this point are intermittent reverse command; sometimes it works, sometimes it doesn't. My radio is a Futaba FASST 2.4ghz 6-channel system, and my motors are wired up in parallel; when I specify the reverse mode on the transmitter, then it works fine, which probably means I need to reprogram my speed controller. I ended up going with a Traxxas XL-5 because I could get it locally, and I have been extremely pleased with it so far. Easy to install, easy to setup, easy to work with. Plus, the speed controller acts as the boat's on/off switch, eliminating the need for any extra wiring. Another issue is the boat's rudder throw; I'm only using the standard Futaba S3003 servo, and while the Illinois maneuvers beautifully with the current throw, she only maneuvers beautifully because she's missing at least ten-to-fifteen pounds of ballast. Later this week I hope to add rudder arm extensions to give me more swing. The third issue, probably corrected by increasing rudder throw, was that my ship would not turn when I was moving in reverse (when reverse worked, that is). Forward thrust in any capacity, and the Illinois answered her helm proportionally to her speed. Have any of you other big-ship drivers had that happen to you before? All in all, a very successful test at my church's private lake. On to more pictures! U.S.S. Illinois at 1/2-2/3 throttle throwing a mighty fine bow wave. Pass in review. U.S.S. Illinois coming about. Running at full power. Illinois turning about. Illinois at rest near the shore for a beauty shot.
That's a relief to hear; for a while there I was worried I was going to be at a severe maneuvering disadvantage.
looking real nice there I tried using an XL-5 for an ESC once. I rated it as one step above a disaster. It has a braking mode that you can't seem to disable, that requires the signal to return to neutral (not just pass through) before going to reverse. I found it to be an issue that simply got in the way on the water. Get an Mtronik marine esc, it'll work much better. Also, concurring with Bob, most of our ships lack any real intentional steering in reverse. I consider myself lucky if mine drives relatively straight in reverse.
Our ships are scale, but water does not scale. What this means is that the forces affecting our models are different from full-size ships. Our scale models turn by redirecting propwash. When going forward, the rudders have lots of propwash to redirect, making for a good turning force. When going backwards, however, there is no propwash over the rudders, so they has very little turning force. While it can be annoying at times, in other cases it will save your ship. If ever your rudder gets jammed hard over, like what happened to Bismark, you can bring your ship safely to shore by backing up.
Lots of brushless ESCs have that name neutral signal requirement before going into reverse. Although it is somewhat easy to do it while jsut sailing around, while in combat it is VERY difficult to remember pausing in neutral before going in reverse. The Mtronik is a good suggestion. So is the Proboat IMO. Both do not require the neutral pause and will go directly into reverse when the stick is moved that way.
For the time being I'm going to stick with the Traxxas ESC, mostly because I have it, and combat isn't until next year for me, lol. I appreciate the feedback, though, and will keep it in mind, because one thing I need to start doing is assembling a box of spare parts, like backup motors, lengths of wire, etc. for this monster... just in case. I'll have it out on the water Sunday once again for more testing, this time likely with more ballast and extended rudder arms on the servo.
If you can, switch to a geared setup for the rudders. You will be able to get more throw by selecting a higher gear ratio. Also if you back into something you won't bend up control arms you'll likely slip the gear instead. (Which is annoying, but simple to fix versus installing or building a new set of control arms.) I've heard some less than good things about the traxxas escs. They have a braking mode, a 1/2 second or so hesitation when switching from forward to reverse. This is for cars I guess. It doesn't work so well with boats. I think switching over to an Mtroniks Viper would be something to very seriously consider before you battle. Steering in reverse is almost impossible with the american battleships with skegs. Some of the german ships with dual inline rudders can steer in reverse, but that's about it. Other than that, really good progress. Throw a bunch of weight in to get her to the right waterline should give you a good idea about any changes in how she maneuvers.
You might want to consider the banebots esc. Myself and acouple others are running these. They need to be water proofed but work beautifully. You can go from full forward to reverse with out any problems and the same the other way. Kim I can bearly turn in reverse with my cruiser. Just enough to move it slightly.
Quick update: got my outer shaft struts and rudder gears from BC yesterday and I've been in the process of installing them; had the Illinois out at the lake on Sunday afternoon with a heavier ballast. Her wake was so powerful that it was sending breakers ashore, quite astonishing several of my onlookers. Pics to follow later!
Nice work and it looks beautiful. I got mine down to speed with drag discs since I don't use an ESC in my system. I don't use gears but my rudder rods work very well. I got the model down to 44.5 lbs and at that weight it sits low amidships. I have excellent throw on the rudders but this ship handles well with out the extreme rudder throw. I have a gear system from battlers using 12 tooth pinion geartooth on each gear mount. The model handles very well in choppy water and brisk winds. Have to watch tight turns in a swell as the aft deck can become swamped. Batteries in mine are used for ballast and standup. I was concerned about stability issues but the model barely leans in tight turns at high speeds. It maneuvers tight and helm control is excellent. Lots of practice with your beast and it will be a deadly opponent.
Amen, Stokamoto! Thus far, I haven't ever had my ship at full ballast; best I've done so far is getting it to the bottom edge of the plan waterline, which if I had to guess, would be between 32-37 pounds. I started out with my rudders on a rod system, and I was amazed at how quick and tight the turns were. When I changed over to the gears, the ship turned even tighter, but the tradeoff was that at full hard over the rudders act more like a brake, which might end up being useful. Right now I'm using BC drag props on my outer shafts to slow it down, and so far they seem to work very nicely. Haven't done a time trial, yet, but I'll wager I'm still overspeed by at least 2 seconds. The ESC I have is performing well, and I'm amazed at how powerful the ship is with two direct-drive shafts and 1.5-inch propellers with 35-degree pitch. When I run close to shore, the wake comes to the beach as breakers. I have my three 6v 12ah SLA batteries in the hull right now, and I'm using two cases of 6,000 BBs as ballast fore and aft, at least for now. When I no longer need them as ballast, I have a handy pair of shot lockers, lol.
Excellent Miller7D excellent. I managed to squeeze in another battery so I got 4 SLAs like Yamato in the Mo. I could only achieve this by having a pair stand up but on either side of the hull with the bottle in the middle. Tom Cromwell is laying a pair flat ahead of the drive motors then the bottle in the middle with single batteries standing up each side. Makes use of the ballast but either way Mo though big is a tight fit. However I feel really good that Mo will not run out of power in a days worth of battling. Even with all that I still had to hadd another 11 ounces in the bow to trim it down. I find the 35 degree pitch throws up a large rooster tail or wall of water on gears and on direct drive it's even bigger. Great for prop washing. On my system I have much large props but 25 pitch on reduction gears . I get a nice wash behing the stern but it doesn't throw up water over the sides when I stop and change to reverse very high. However the water looks like it's boiling bubbles behind the stern when moving . Good thing is I got all kinds of options to try various combos so I look forward to trying out my 35 pitch on it and see how it handles. Mo reminds me of my Bismarck on how nice it handles. Happy to be an Allie with a major capitol ship.
I know what you mean about that rooster tail; with her current ballast and trim she churns up the water something fierce. Below is a picture of the Illinois running at full power; you can see what her mass and speed is doing to the water. The one mark in her favor is that in this regard she truly does act like a major capital ship, in that when she passes by, you're going to feel it, one way or another.
Looks beautiful. Nice wake. Well it's a beautiful day here today so I am taking Missouri out and the Go Pro and try to get video. Pictures I can let the wife take of it as it is cruising. The ANCHOR BULBS or Nostrils, I don't know what tocall them what did you make yours out of?
Thanks. I took a couple bits of small scrap plywood or some similar material, marked out the appropriate dimensions (or as close as I could, since the plans I have don't really correspond to the beautiful reference photos I used from www.navsource.org), ground them down with the dremel, and then slapped 'em on with wood glue. It was all done mostly by guesswork, and I think mine are actually a bit too big. But yeah, definitely a lightweight, easy to dremel material was used.
They look good. Think I will do the same no that I am onto the next phase which is detailing . The BB cannons and hook ups will go in next year.
When are you getting together with Ethan and JP for another build? The little Scharny had a good showing at its first Nats.
