Okay Need a little help here. I think I just confused myself. I'm building a Des moines class heavy cruiser with duel sterns and 1 bow cannon. Now the question is how many servos do you need total for the whole ship? I want to use micro servos to save on space and weight. If my understanding is correct I need one for the propulsion, one for the guns (if you can run both guns off of one servo)and one for the Pump. Is this correct? Also do they make dual servos were you can run more than one thing off it? Ex. switch one way for pumps and switch the other way for lights?
You're missing the one for the rudder but other than that it sounds ok. You can run pump and lights off the same servo like you do for the guns(up(bow gun), neutral,down(stern guns)). If you want to use an on/off type switch like some radios have for landing gear youll probably have to modify the switch/radio to get the third position, there is a guide to doing that on the spektrum somewhere.
I'm not sure a micro servo will have enough strength to trip a poppet that is fully charged. The Des Moines is a big cruiser, use a standard size servo (www.servocity.com) for the guns and rudder.
When buying servos which is better. 90 degree radius or 180 degree radius? Like for the rudder, would 90 degree be fine?
You can use the large and small gears from Battlers Connection (as an example) to increase the throw on the rudder. See the Cleveland build for the layout.
Nope the radio for $179 has no servo's. I was over at Rick's last weekend and looked at the new radio, no servo's, but I do like the fact that the battery case is built into the radio, you just pop in the AA cells. So you can go with any capacity you want. It comes with 1600 cells.
With a Des Moines the number of servos you use is alldependent on how you are triggering your cannons and pump. I personally have a single servo in my Des Moines. That is my Rudder Servo which is a Hitech 311 standerd servo. I use a gear setup for controlling the rudder and had to use the radio to limit the servo throw so it does not turn the rudder to far. With the BC gears you can actually rotate with this servo further than 180 for the rudder and at most you want 60 to either side to keep speed up during a turn. Yes full speed on this ships helps it turn better. As soon as the rudder starts dragging and slowing the ship your ability to turn gets cut drastically.
If it's not too late to talk you out of the dual sterns/single bow idea...go with triple sterns instead. You'll do far more damage and cause enemy battleships to treat you with more respect. It's also going to require less to set up as you can link all three guns. That being said, and it's my duty to give you the best advice I can, since you probably aren't going to listen and switch to triple sterns (until next year after you've seen some battling)and assuming you are using all old technology (read MAG throttles and servo/poppets as opposed to ESCs and gun boards w solenoids) you'll need a max of 4 servos in your ship. One will be attached to the rudder, and I've never heard of any turning systems that can eliminate this servo. The other servos all have alternate technology which can eliminate them, but the rudder servo seems to be non-negotiable for the most part. Servo #1 will be used with 2 micro-switches to create a MAG throttle. This will be your forward and reverse. This can be replaced by an ESC if desired. Servo #2 will drive your pump, and one or two of your guns. This could be replaced with gunboards and solenoids. An ESC can be used as a pump control, or perhaps a gunboard/solenoid combo can be used to kick a switch to activate your pump. I'm going to start experimenting with using an esc for a variety of reasons, but haven't tried it yet. A triple stern set up simplifies things by removing one servo...moving the servo back would fire all three stern guns, moving it forward would actuate the pump. servo #3 will drive whichever guns aren't controlled by servo #2. This will be either the bow gun or the stern guns. If you use an ESC for your pump, you can eliminate servo number 2 and run both your bow gun and your dual sterns off one servo. There would be an open channel which you could use for a light switch if you wanted, but otherwise this channel is probably going to waste as most people would link the dual sterns to fire together. I'm a bit different with my dual sterns. If I were setting up a ship like this using your chosen gun arrangement, I'd use the 4 servos. Helm control would be standard, on the other side of the radio, up would activate my pump (you could have your bow gun here but most guys don't use bow guns, and if you ever switch to a ship with sidemounts your pump will probably go here, so might as well get used to the positioning) Back will fire a single stern gun. Left will fire the other stern gun. Diagonally (back and left at the same time) will fire both at the same time. Right will be left to drive your bow gun. If you decide you want lights or something like that you can always attach them to your pump and use your pump control to kick the lights on if you decide you want them. I haven't ever used lights personally.
