For several years now I’ve been working on this liberty ship. Time has always been issue in building it. General inexperience hasn’t helped much either. As you can see, the frames are cut, water channeling is in place, and the prop and rudder are installed. It’s being built under the MABG (Big Gun) rules. I’ll try to post updates as I go. Probably infrequently, but we’ll see. Really what I need is building advice. Here’s a few things I’m considering. (1) Servo placement. I had originally intended the servo to sit on a pair of arches. That was before I filled the bottom with cement filler (note the height of the arches.) In retrospect, I really should have put the servo mount in first. Oh well, learning experience. Now I’m not quite sure where to put the servo. For reference: space is limited where the rudder is, so I opted for a chain connection instead of an arm. (2) Motor. This is more of a question for the MABG members on here. This motor I’ve got here is one I inherited from the Brooklyn hull. I can’t shake the feeling it’s a bit overkill. What’s the running speed supposed to be again? (3) Power supply. This is the most contentious part of boat building for me: Figuring out the batteries. My current plan is to use lead acids in two separate circuits. One circuit for the ESC, motor, and rudder; and the other for the pump. Both 6 volt I believe. Would this be acceptable? (4) Recovery line. Mounting a recovery line in itself is not a big deal for me. It’s just where to put it. If I put it directly in the water channel, I’d feel a little uncomfortable as the fiberglass is a bit thin there. I’d rather not tear the bottom out of my boat when I try to raise it. Could some reinforcement be in order? (5) Rib reinforcement Fairly simple job I suppose. What to do the deed with though… Plywood strips of a certain thickness and then glued on? Please note that this is a Big Gun boat. Those ribs need to handle a degree of punishment. I think that’s everything. I’ll be glad to see more progress made on this boat. I’ve been dragging for so long now it’s discouraging. Thanks in advance for your replies!
Hi Propshaft, It's been a few years since I built SS Nathanael Greene, and I sold her a few years ago, but here's a few swings at answers: 2. Motor: that looks like overkill. I ran Greene with a cheap 280-size motor from Radio Shack. 3. Power: 6v should be plenty of push for the motor and the pump. Keeping them on separate circuits makes construction, troubleshooting, and repair easier. There should be plenty of space and displacement available for any reasonable size batteries. I used two four-packs of D-cells. 4. Recovery line: I drilled two small holes in the bottom of the fiberglass hull, tied a wire loop (picture hanger wire) through, then waterproofed with 30-minute epoxy. Then I tied the recovery line to the wire loop. 5. Rib reinforcement: 1/4" square bass wood with 30-minute epoxy has been my choice. Looking forward to seeing you on the water!
A couple of key factors to remember to maximize your maneuverability: A. The construction rules allow a 50% bigger propeller than the scale ship, which works out to 22% greater diameter . B. Convoy ships get a 100% bigger rudder.
