johnmCA72
Posts: 216
Score: 100
Joined: 5/15/2005
Last Login: 2/8/2010
From: Grand Marais,
MN, USA
Status: offline
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quote:
ORIGINAL: TheGreatMoo
yeah my 4 channel has the left stick hooked up to the rudder and the propeller, and my right stick controls my turrets rotation and the separate firing of the front and rear turret. when you push the stick up the servo hits a switch on the ship and turns on a motor in the front turret that pulls the springs back and shoots the bb out. and when you push down the servo hits a different switch that fires the rear gun.
That sounds pretty typical & can work well to get you started. As you get more advanced, you may find yourself wanting to change things up - or maybe not! Some people run forever on a simple setup like that & are completely happy with it.
quote:
ORIGINAL: TheGreatMoo
I'm not quite finished with the guns yet but my ships coming along nicely right now all i have for waterproofing is a plastic sheet over my wooden frame which looks really bad, how do you guys waterproof your hulls?
I'm not at all sure what you mean here. Do you have plastic sheet stretched across unplanked ribs, or have you skinned the ship with balsa & covered it with plastic sheet?
The accepted method is to sheet/plank the hull with balsa wood of an appropriate thickness per club's rules. In my club that can be 1/16" to 1/8", depending on the belt armor that the original ship had. Our club, like most, also allows a layer of silkspan over the hull. I've found it easier to apply it to the sheeting first (with airplane dope), then install it with the silkspan on the inside. I attach sheeting to ribs with thick CA glue. First, I cut & bend the sheet to approximate size, allowing a little extra sometimes (better than coming up short!) that can be trimmed off if necessary & dry-fit it to the hull to make sure it's right. After I've got the size & shape close, I apply a bead of CA to the ribs & spray kicker on the inside surface of the sheet. Slap the sheet on, apply hand pressure, & count to 10 - stuck! In a head-to-head contest a couple of years ago, I complete re-skinned my HMS Nelson in the same amount of time it took another guy to patch 8-10 holes on a transport. Granted, Nelson is an easy skin, & I had all my materials lined up, ready to go...
I fill gaps & fair in overlaps with a filler such as light spackle & sand it to my preference. I don't go nuts trying to get baby's-butt smooth - this isn't for show. I then paint a couple coats of dope over the balsa, then spray the whole thing with gray primer, which I think gives the end result an acceptable "warship" color, besides being supremely easy. Mask above the water line & spray the bottom red (Krylon safety red is my favorite). Apply 1/4" black detailing tape (available at hobby shops & auto parts stores) for the waterline, & it's done! I also usually spray clear dope over the final hull to keep the tape from coming up.
The whole process takes maybe 2-3 hours, spread out over 3-4 days to allow time for everything to dry in between stages. Sometimes I get a little leak, but that's no big deal - I'm expecting to get bigger leaks eventually, anyway.
quote:
ORIGINAL: TheGreatMoo
Ive been having problems with my motor, its overheating and shutting down. my speed controller can handle up to 8.4 volts and i have a 7.2 battery attached to it so i don't know why its overheating. it was in sunlight but idk if that could cause it to heat up so much. i was thinking on mounting a small fan above the speed controller or something. any ideas?
are there bigger speed controllers than the 8.4 volt i have? cause i really want to put my 12 volt battery in the ship cause it would run longer. what size batteries do you guys use?
It isn't volts that causes things to get hot, it's amps. Think of voltage (volts) as being the electrical equivalent of pressure (like in a fluid-based system) & aperage (amps) as the equivalent of flow rate. Run time has nothing to do with voltage, but everything to do with amp-hours (AH), or, the rate of flow over time (amps = rate-of-flow * hours = time; amps * hours = amp-hours). There are 2 different issues at work here, & you need to consider them separately.
If your speed control is getting hot & shutting down, that's because your motor is drawing too much current (amps). Shutting down is the controller's self-preservation mechanism - current is converted into heat, of which too much is a bad thing. Speed controllers & motors need to be matched to one another. If the motor is drawing too much current, it matters little how many volts are available - too many amps are being drawn through the controller. I don't know what motor & speed controller you're using, but they aren't matched to one another very well. Keep in mind that most model boat motors & speed controllers are built for racing, where the objective is to go fast. Lots of speed means lots of current, which in turn means lots of heat. For any model ship, it can be a challenge sometimes to go SLOW enough. Nothing looks sillier than a model ship that's too fast! Not to mention, most if not all clubs have speed limits for each ship class. Tactically, you'll want to get as much speed as your club allows for your ship, but practically you'll want to keep it in a pretty slow range.
You are absolutely 100% dead wrong to suggest that your ship would run longer on a 12V battery than on a 8.4V battery. It's not volts, but amp-hours that determine how much run time you'll get on your ship. Your motors will draw (consume) amps, not volts. You measure time in hours (or minutes, seconds, days, etc.). If your ship draws 1 amp, and you have a 10 amp-hour battery, you should expect to be able to run it for about 10 hours - the math is that simple: rate-of-flow (amps) multiplied by time (hours) = amp-hours. If your ship draws 5 amps, you should expect to get about 2 hours of run time off that same 10 AH battery. If it draws 10A, you can run it for an hour. Nowhere in that calculation are volts ever mentioned, because they have nothing to do with it.
Reducing the current drawn by your motor will have 2 effects: It will increase your run time (fewer amps drawn, same AH available) AND stop your speed control from overheating.
Suggested research: Familiarize yourself with Ohm's Law (google search will find plenty of info).
JM
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RE: what kind of radio to use??? - 
