Hello, I am building a DKM BIsmark and would like to make it big gun. I tried to contact all of the big gun rc naval combat members in the area ( Pheonix, AZ ) to meet up with them to see how the cannons work, etc, but none of them have responded. Does any one have any advice as to what I should do to get my DKM Bismark model in big gun format? Thank you -Dexter
Good luck. It's much easier to get started if there's someone else nearby who already has a boat and some experience working on it. Even then, getting started is no easy task. One of the big challenges right now is getting cannons, since Strike Models doesn't yet have their big gun cannons available yet. Tugboat, Kotori,myself, and others are looking into alternatives. If you have a metal lathe and milling machine you can make your own. The basic shape and principle of operation isn't particularly hard to understand if you can see a cross section with a good explanation. I remember an animation that showed how it worked, but I don't know where it is (can anyone help us out here?). You could also order JC White's cannon plans from Strike Models. Once you get cannons, you can worry about the hull, gas system, motors, electronics, and radio. Those are much easier to get than the cannons.
Thank you for the advice, Gascan. I don't have a metal lathe or a milling machine so my only option then is to wait for Strike Models, right? -Dexter
Dexter, sorry to hear this. I would just start building and hopefully some stuff will resolve itself before your done with the hull. Hopefully you can find someone you can call that doesn't mind you calling to help when you have questions. Unfortunately on the board sometimes those can go unanswered even with all of the knowledgeable people on here. Gascan is right, see if you can find like a smaller lather used so you can play around with it. Always could try harbor freight.
If you don't have any of those machines, there may be a maker space like the Tech Shop that will let you rent time on one. There are also online machine shops that will make parts for you if you draw them up for them. As I recall, the more parts you order from the online machine shop, the cheaper each part is. They have to set up the tooling once, but they can then run through the job for much less than the initial set up. Here is a cannon build thread with a CAD drawing showing the cross section of a cannon. The red is the valve body, the green is the buna ball and push rod that form the poppet valve. When the rod is pushed forward, the ball unseats and air flows into the valve and up. From there it passes into the white piece, which is both a bushing for rotation and a retainer to keep the magazine from blowing off. The air enters a plenum between the purple and aqua parts and flows to the breech. The light blue is a single magazine tube and breech. The red ball is a single round resting in place on an adjustable white pin. Other rounds will rest in the magazine tube and slightly overlap the round in the chamber. Air flows up below the round in the chamber, pushing it up and out. The round also pushes the other rounds back up the magazine tube, preventing them from rolling into the breech until after the air is past and allowing a single ball to be fired at a time.
The new and awesome 3d printing capabilities of Tuggy may make procurement of cannons easier as we in the hobby begin to wrap our heads around ways to print the hard to make stuff and MacGyver a way around the rest. The guys in this hobby are pretty resourceful and can do stuff like that
Here is a link to the animation I think Gascan mentioned earlier: www.rcwarships.com/rcwarships/nwc/gun01.html Hopefully it will work, I had a hard time posting it as a link from my phone.
Thanks so much. It all makes more sense now. I have never seen a big gun cannon so I don't really know what are its parts. Would JC White's plans be a good starting piont for drawing 3d plans so that I can then print the parts through the online machine shop? Thanks again for the help. -Dexter
