I'm a big fan of using a chrono to find gun velocities, but only on the bench not at the lake, atleast not universally. The amount of time it would eat to chrono every gun on every ship before every sortie (how else could you verify that nobody tweaked between sorties) would be way to much for any decently sized event which is probably where it matters most. Can our guns hurt people? sure, deal with it. It is a game based around shooting guns in close proximity to ourselves afterall. And realistically the current "super mega guns of unholy death and destruction" are already pretty close to the realistic max velocity and are already well into the realm of diminishing returns. If you're really serious about limiting gun velocity there are a number of good ways that require a lot less time and equipment to enforce. Lower the allowed max pressure, lower max barrel length, or set a limit on the size of the feed line to the gun. (pressure, barrel length, flow volume) Gun velocity (like pump rate) is often more about intimidation than actual usefullness. (oh your boat can pump 4 gal/min? sounds good leave it on till it sinks and let me put a few thousand points of belows into you, great idea well as long as you're on the other team)
I see your point, and agree. Testing every barrel on every ship before every battle is unrealistic. Testing one or two barrels, on different ships, at random, isn't. Applying peer pressure by letting all present know the results of the testing good or bad is a way of allowing each member to self-regulate and decide if they really want to risk being the one caught with way over-velocity cannon..... which is something they can check if they have their own chrony. Allowing testing by challenge is a less diplomatic way of doing the job, and may create bad blood, so I'm not really a fan of that. Sometimes, however, there are thick-skinned individuals who just won't take the hint. No, don't think of their name right now, even if you do have one in your club. Ultimately, it's up to your club and it's members to decide how you limit muzzle velocity, and to each individual member to abide by the club's decision. As for barrels, what's wrong with scale length barrels? I've seen photos of some REALLY long barrels on some ships, and thought "nice ship...WHOA! those guns are UGLY!!!" I'll ask at this point that we not hijack this thread too much more, and apologise for doing so.
One or two questions Herr Professor: Is the silicone tubing absolutely necessary. I am not sure I understand the purpose other than elevation control. Is there any reason a 1/4" ball bearing cannot be use rather than a 7/32" one? I have, and can use, several thousand 1/4" but cannot find locally any 7/32"
The silicon hose is essential to the function of the gun. It is NOT there to allow flexing the barrel; it is there to act as a restrictor to the BB, holding it up for a fraction of a second, allowing gas pressure to build up behind the BB until it pops through the restriction and flies downrange at a much higher velocity than it would without that pause. In a Foster breech cannon, this function is served by the O-ring that you tweak. Big Gun cannons do not have the restriction, and so use a much higher gas flow to get the projectiles up to speed. To answer the second question, there is nothing preventing the use of a 1/4" bearing; just use a drill bit slightly larger than the bearing's diameter, like 9/32" or so. I do recommend using stainless bearings, if only so you don't have to worry about rust in your breech.
I was not happy with how the guns turned out, durability-wise. I need to find good clamps that are small enough to be useful in holding the silicon tubing on the metal tubing.
I have a PDF file that Pete D. put together concerning geek breach cannons. It used brass tubing as a clamping material. It looks t be a bit more complex, but not unreasonably so. I don't remember where I got it from but I can send you a copy. I don't think he'll mind. If he does he can just make you walk to Nats or something.
Please send it He won't make me walk, he can't afford the gas for the Deathmobile by himself I can make it to Houston in my hybrid on 3 tanks of regular gas with a bit left over. Why have I been running a small cruiser? Fits in the car
Could you send me a copy too, I'd love to look at it? Plus there's nobody that can make me walk. lol Thanks, Beaver
Let me check with Pete. He's funny about such things getting out. Rest assured that if I can get the geek breech to where I'm happy with it, I'll post details.
Yeah, that looks like it. I didn't know he published it for open consumption. he can be very secretive about stuff sometimes.
I'm not sure how intentionally published it is. Google found it quick (searched for 'geek breech cannons'), but I don't see a link on the MWC articles page at a glance.
Ah, from the Iron duck thread 4 years ago, that file was supposed to have been pulled... Maybe someone could revise it and link it back up with proper notation?
Hey tugboat, other than the clamp issue, were there any other major issues with this design? I'd like to use them for my Bismarck
I experimented w/ the geek-breech cannons when I first joined the hobby. Here is my (personal) opinions: Advantages over compression nut "aka Foster or BC" guns: No tweaking needed. => less maintenance or fiddling lakeside Disadvantages: No tweaking possible. If weather is too warm, gun will shoot "soft". If too cold, the gun will jam If the gun jams, full disassembly is required to clear Much more complex to build correctly than a Foster. If not done correctly, disassemble and start over. Overall, I think Tuggy has a point about these guns being good to put on a loaner boat, as they're lower maintenance if built right. But IMO, the many disadvantages outweigh the few advantages. A Foster-breech gun can be built in the same or less time, and gives much more flexibility of performance.
Foster breech is simple and easy enough to make. The way that I was doing the geek breech, it was easier to make, but the clamping issue was not resolved, so that limits how useful it'd be What I'm using now is a Foster breech with very thick-walled brass tubing for the barrels (like 1/16" wall thickness). You turn a groove in the breech end, and solder a ring of wire into the groove, which is what the compression nut pulls on to tweak the gun. Very hard to dent a barrel that thick. It also looks like a scale cannon barrel Brian makes the barrels and Tees for me, but I use a bypass line to the back of the breech and he does not.
