Love that smooth first layer. Prototype big gun style rotating fast canons. The chamber will not be pressurized (at least not directly). The breach is sealed with an interrupter piston valve that opens an air port at the top of its travel. The magazine half (two magazines per gun) has been painstakingly measured to fit 50BB’s with each magazine section having its own firing piston. That will allow for built in reconfiguration and future proofing (if single units can be divided into 2x 25 shot guns it is as simple as loading 25 rounds per side)
I was reading some really old threads about the topic the other night. It seems the big drawback is the slow RoF because with fast gun cannons the rounds are forced against the piston with a shot of air and only need a short burst of air to operate. While big gun assemblies pressurize the whole magazine and require a much larger shot of air (though at lower pressures). With my design, there is really no way for the next 5 rounds to roll away from the piston. I just need to work on the slope INTO the feed ramp a bit more. Once a round is in there it rolls out with zero issue. I need to print the valve surface and then it can all be screwed together. Also somewhere in my measurements I added 5mm to each side so the up tubes do not line up with the turret face. But it is just a POC right now, not exactly ready for battle.
love the work you are doing, especially the deck. Have you thought if pricing is within reason start making deck kits to sell.
Thank you! Honestly if someone wanted just the decking Id probably just charge for the time and materials. Id also have to redesign it to be more of a 'snap fit' with interlocking joints. I want to see how it holds up to the summer and maybe some battles first. It is pretty well supported by the subdeck so I do not imagine it sagging, but I have yet to be able to test that. The nice part is, if it does sag, I can probably just put it in the oven at the lowest setting for a few minutes to flatten it back out. I might end up adding aluminum rods to the underside just as a precaution.
That is cool, are you going to be able to depress the guns of the Bruno turret. If not still a well done.
The idea was to develop a rotation and pivot system. I built the cannons into actual barbettes with that goal in mind. So the -almost- entire cannon system lives inside the space of the barbette. All but the firing circuit, solenoids, and propellant. The pistons, magazine, manifolds, all are being designed to fit in there -eventually-. For simplicity sake I have designed a 3D printed compact coil center barrel style mag (working on a big gun style fast shooting cannon as well but thats a yet-proven design). I need to get the parts to test the prototypes. I intend to have the guns fire at their real-world limits of 0° to -3° on A and D and 0° to -9° on B and C. (Not above horizontal..) At this point, with the current rules in fast gun, just having them rotate will be good for this version of the ship.
Beautiful build so far and very innovative on some of your construction techniques. I want to see new people have a good time on the water, and if you show with a Bismarck that only has 3* of down on it's guns it's gonna be a rough time for you. Your rotating turrets and detail work are A+, I'd hate to see you have a bad time in the hobby, so I'd honestly recommend building two different decks for the boat. Build a second set of decks with traditional fastgun cannons, if you come down to a build session we can get you set up with a bismarck worth of guns in no time, so that way you can battle the boat competently in IRCWCC. Then, keep your first set of decks with the awesome rotation mechanism and your experimental guns that is your more "scale" show it off kind of setup. Not trying to shoot down your new ideas, I've been the new guy in a big boat before, it can be rough. That's why I just wanted to drop in and leave my $.02.
Oh I am already prepared to have the boat shot to heck just so long as she sinks a Hood Going to need to test the feasibility of the building technique somehow! The way I look at it, the decking and superstructure were built to be reparable and easily replaced. PLUS the real ship took a pounding so itll just add to the realism. 30 seconds with a 3d pen and no worries. I know Im going to be terrible. I played paintball for over 20 years and was still rubbish until the day I 'retired' from the sport. Still enjoyed it. If my knees would take it, Id still be playing. I should use some of my replaced sections as target practice with my BB gun to see what would happen. But that thing shoots at 1000fps, not the 250ish that Ive seen in posts. Maybe the airsoft gun since it is lower 400fps. As for the guns, I should be able to easily fit a 'traditional' 50rd coil mag in the barbette. The entire gun system is modular so I can make any style fit inside with only a few hours of printing. Part of the plan was to subdivide the unit (it was against the rules years back (2009) but dont see it in the 2021 rulesets..?) into 2x25 canons and have all 8 barrels working. The rotations wont be used IN battle. With just bench testing it is such a pain to get them where I want (they are on 360* servos attached to the variable speed knob). If I tried to slew them on a pond Id end up with broken cannons or worse. It would be a between battles change at best and a 'putting around the pond between rounds showing off' at worst. I appreciate the veterans looking out for the new guys. If the boat sucks, it sucks and the next one will be better! I already have an Iowa mold (I started building the Big J when I first got into this in 2008. Bought the hull from a guy in Australia but it is terrible. The hull is not symmetrical at all.) that I will eventually build up. Also planning on building a Scharnhorst and Prinz Eugen for my boys for when we go to the lake. Not to battle, but if they are armed... -shrug-
Only ships class 2 and below can divide units. Bismarck, being a 6.5 unit ship, can only use 6 individual units and 1 half unit. Check out pages 12, 13, 14, and 15 of the rules for the sections specifically related to this. Also keep in mind the cannon positioning rules with quadrants and dual sidemounts.
AH! There it is. I seriously scoured that document and did not see it.. Since the turrets are geared, I can easily position them exactly where I want to cover what ever quadrant. It is as simple as 'unlocking' the gear from the gear train, rotating the barbette, and relocking the gear. Oh... I should fab up a reverser gear so instead of pointing to the same position, they are opposite each other... Giving me more ideas :-D So this is where I get lost in the rules. 6.5 unit ship but I can only have 4 one unit guns as to not violate any of the quadrant coverage rules. So... 2 and a half units of pumps :-D
There is no limit on the number of guns aimed in the forward and aft quadrants. The most common gun layout for a Bismarck would be dual stern guns in D, sidemounts in the other three turrets. Bismarck is allowed 3 sidemounts because it's over 60" in scale length. The bow sidemounts would have to be on opposing sides (one port, one stbd). The stern sidemount would typically be 1.5 units (75rds), or you could use the half unit for a second pump (so stern sidemount would be 1 unit). The stern guns could either shoot straight off the back, or angled 15 degrees (typically to the opposite side as the stern sidemount) The other common gun configuration would be two stern sidemounts (opposing sides), one bow sidemount, and one or more bow guns, with the appropriate # of pumps to make up the unit total. I've seen the bow guns in both A or B turret. I have a bismarck hull, when I build it I plan to use the traditional (most common) gun layout described above.
Very interesting cannon design. As a collector of cannon designs of every sort, consider me intrigued. I'm not entirely clear how it's supposed to operate, however. what parts are supposed to move, and what parts aren't? Does this use a typical Fast Gun o-ring breech?
THANK YOU! Not sure I would do bow forward guns as she has an atlantic bow and I dont care to have my nose shot off by my own weapons
Not really. Ive been a paintball player for 20+ years and was a marker tech for almost half. I consider myself to have a pretty good understanding of pneumatic projectile launchers and how they function. There is a type of valved marker called a spool valve. Basically, it functions like that. Air comes in under the piston and pushes against the piston valve which sits in a cup and spring until it builds enough pressure to overcome the spring force and the piston goes up. While it is moving up, it forces the BB into the firing chamber and since the piston and firing chamber are a sized fit they should form a good enough seal. At almost the top of the piston travel, it will leave the sealed cup allowing the air to flow out into the valve chamber, through a hole in the piston, and out from under the BB propelling it out of the firing chamber. I will post some diagrams in a bit. Just got suuuper busy at work.
While I have seen someone not realize that their guns were hitting their own superstructure (and then careening towards a group of captains), not shooting your own deck was implied. Bow and stern guns can be aimed within 15 degrees of centerline, so virtually all ‘bow guns’ are actually aimed 15 degrees off one way or another, typically with as much down angle as the geometry will allow. In my Missouri the bow guns in A turret hit close to the waterline at the bow of the boat. Using B turret allows more down angle but a tighter effective range window for hitting the target.
I was also an airsmith for a while and I've been thinking about how to make spool valve cannons work since I've discovered the hobby. I think you are going to run into the issue of finding a spring that is both strong enough and small enough to fit inside the cannon. I would look into a more shocker like design instead of an automag.
