It's kind of like a new car... I think I'll take a crack at it with a bb gun to get rid of the "new".
I finally got to do a float test, with what I would consider less than promising results. The stability seems terrible at best, but I was way on the light side. I had most everything in there except the magazines, breeches, and superstructure. I was floating a little more than a quarter inch too high, mostly due to the elimination of the gyro and the fact that I thought I would need to be at 1-1/2 lbs or lighter. I was at one pound 6 ounces when I floated it. Somehow I managed to build a tiny destroyer, and wind up needing ballast..!?? Hopefully I can add some strategic ballast to improve stability and get her down to the waterline. Seems like it will take almost 1 pound of ballast to get her to the proper float level.
You're underweight? What kind of batteries are you using & with what capacity (Amp-hours)? If you do need to add weight, I'd suggest adding more batteries vice deadweight ballast. Since DD's run around alot, having power to burn is a good thing.
The batteries are LiFe. In the as - floated configuration, there were 2 batteries, a 700mah and an 1100mah. The problem with adding more is the space constraint, there is just NO room in the hull.
Maybe trade out the 700mah for another 1100. Should be minor difference in size and for that matter, a minor difference in weight, too. OTOH, everthing to do with weights in this boat is tiny, so an ounce or two more might help. Another thing you can do that will help signifcantly with stability (and add very little weight) is putting bilge keels on. Great looking build.
Just wait till you get some superstructure on! Getting my Mogador to sit up straight was a real "balancing act" to say the least. I had to go over weight and push the max plus the 10% variance allowed by IRC rules and she's still very tippy. FYI, I'm running 3.3AH LiFe at 15V which was giving a decent one hour's run time. ST
Just thought of something. Was the original ship flat bottomed like your build? I doubt that it was as most early DD's were round bottomed to reduce drag. If this is the case, your extra buoyancy is coming from the underwater volume due to the more square bilges. ST
Unfortunately the 700mah battery is only there because that's the biggest that would fit in that space. Bilge keels might be a good idea..... I will have to see if the full scale ship had them or not. @ Steve.... You aren't kidding about the sensitivity of the balance! I would call it hypersensitive. I checked the "plans", and the full scale ship was flatbottomed. This ship was built from a CAD makeup done by another on the forum, so I don't have actual plans, but I found an unclear set online to rreference. There was an extra 3/8" added to the hull depth as allowed by most rulesets. The 1-1/2 lb finished weight was an arbitrary weight I was shooting for based on some reading. Tugboat referenced 2.48 lbs, which is probably very close to the maximum draft.
MAIDEN VOYAGE!!!!!!! Woooo Hoooo!!!!! I FINALLY got a boat to float and move under it's own power!!!!! Too Cool!!!! I removed the unfinished torpedo because it kept rolling around, and replaced it with another battery and a couple spare gyro rotors to get her down to the waterline. I weighed her down to 2 lbs, and centered and evened out the ballast to help her float level bow to stern and without list. This caused her to float on the deeper side of the scale waterline. I would certainly consider it a successful run. She drove reasonably well, although I surely need to hone my boat driving skills...... With her sitting lower in the water, stability was much better, absolutely acceptable in my opinion. Even once the super structure is on I expect it will be acceptable. Since this is my first boat, I don't really know what constitutes good maneuverability, but I suspect I will need to try to improve on the turning radius. There were no leaks or other major problems. The biggest noted issue was that the ESC seems to "brown out" for a second if I go from full forward to full reverse. The rudder servo also took on a touch or water and wigged out, but there was no waterproofing done on it at all yet. Pictures (and a video if I can figure out how to post it) forthcoming.
It's the Hobby King 12a Aircraft ESC that I had flashed new firmware to, giving it reverse. It's possible there is something in the firmware options I configured wrong...... But it's been so long since I flashed it I don't remember what I did. Unfortunately, it is scotchkoted now.
Run mode needs to be set to TWO (Not 2TWO (yes there is a 2TWO)) so that it does not pause between forward and reverse.
I started on the stupidstructue today, I call it stupid because I'm sure no matter how light I make it, instability will be the end result.
I figured I would try to make it from 1/16 plywood first... if that's too heavy I can try something else. I didn't get very far.... The mess I currently have in the garage is kind of work repellant
