Work began in earnest today on BM-7. Rib templates have been cut out and transferred to 1/8" plywood. I had to go with 1/8" because of the rib spacing on the plans--they came out to 1&13/32", so not quite the 1.5" needed for 3/16" ply. I still need to mark out the waterline, keel, water channeling, and bottom of the penatrable area on the ribs. I also still need to resize the deck and superstructure plan sheets, which can be a bit of a pain living in the sticks. I will be cutting the ribs to scale and adding the deck and sub-deck above to squeese an extra 3/8" internal space, otherwise, I'm looking at 1&5/8" of room from the top of the ribs to the bottom of the deck. It will be armed with the Arizona guns from the late Adm. Popov of the MBG once I rework them some. The CO2 bottle will be in the superstructure. If the stars align just so, I'll arm two of the 4" guns for stern action, but I am not holding my breath on that one because this is one TINY boat, and I am going to have a heck of a time fitting in the mains as it is.
Alas, I did not make it, but I have the hull, motors, differential thrust mixer, and guns as of yesterday. I have a picture of the original big-gun set up somewhere and I'll see if I can dig it up. It has been raided for parts by the club over the last couple of years. I don't think it is currently legal in any format because of the lack of a rudder and the use of the props to steer. EDIT: That was easier to find than I thought.Here you go!
I know, I will eventually build it up with a 1 unit gun and .5 pump as an easily traveled with boat for willing treaty and fast gun clubs that don't mind battling an oddity that breaks a couple of construction rules. Supposedly it spins in place but takes in water at speed. I will probably be sticking with tiny boats from now on, Back on topic: I left the house three hours ago and just got back with re-sized deck and SS plans...
Spent some time in the shop re-working the cannons to change barrel orientation to the magazines, make them easier to load, and increase magazine capacity to more than fifteen. This is breech work so it may take a few more days to iron out.
Got the deck, sub-deck, fore and aft keels, and some of the ribs cut today. I am going with only the odd-numbered ribs and 1/4" ply.
I just came to the realization that the freeboard on this is so low by the time my pump primes, it may be decks awash.....
Pump well. Make a box in the bottom between ribs and plank underneath with 1/16 ply. Gotta cut out a small section of keel to do it.
Mike, I am running a double keel in the center of the ship wide enough to fit the Arizona accumulators, and sheeting the bottom with 1/32" ply. That said: Plan 1: A narrow and deep-ish water channel with a slope from the top of the impenetrable area to move the water to the channel as quick as possible. Plan 2: Drop in a pump well below the scale keel. Not my preferred option as it would change the scale outline of the hull, but it has the added bonus of allowing me to move my tank a bit lower in the hull for better stability. Plan 9 (from Outer Space): forgo the pump and take my chances. Progress has been made sheeting the bottom of the hull--at about 70% right now.
Thanks Carl! The hull is now 90% sheeted and I have started blocking out the bow and stern. Shaft position is ready and I think I have my motor layout set. Stuffing tubes will be about 3" it looks like. I had to add 1/8" stringers at the 45 degree turn at the stern because, well, it is an 85 degree turn and I need something with which to adhere the balsa. I have a feeling that gap filling CA will be necessary. Tomorrow, I will need to pick up more balsa and hard stock, then I hope to begin sanding everything to its final shape. Once that is done I need to remove the vertical section of the last rib (19) and place in a 3/16" false rib so I am 100% spacing compliant and again have something to adhere for sheeting the stern. Since I have my motor position set, I was able to do a better layout test. The first rule of combat boat construction is that the guns have to go where they have to go. Rule two is that your motors have to be in a position to drive the shafts. Rule three is keep the bottle low. Now, I have a slight problem: where in the heck am I going to PUT my pump. Yesterday, I was just worried about priming it--now I am worried about fitting it in. That and the rudder linkage. There is almost no room back there.
Just a thought. Battlestations pump capacity is volume based. Use a small positive displacement pump and put it where it fits. Then just drop a "pickup" into the water channel
