RC Tank Warfare community hobby forum

Unusual sound effect on the video. First boat I've ever heard sound like a railway train.

I'm assuming that you will, of course, have operating water cannon.

One thing intrigues me with rc submarines. I always thought radio waves did not travel at all well underwater, so if you flood the sub and it sinks, how do you send the signal to get it back up?

Robs pretty much hit the nail on the head, static dive subs involve using one of the various dive systems available to change the submarines buoyancy. At neutral buoyancy the sub will either hover under the water or sit with the top of the conning tower just at the surface.

Most of my subs use piston tanks which are basically syringes to pull in water increasing the weight of the sub (or being really accurate decreasing it's volume under the water). Other systems use a pump to move water in, some use gas to blow water out. All have positives and negatives.

This is a good read if you want to know more.

http://www.subcommittee.com/rcss-divingsystems.html

It wasn't the mechanics so much as the electronics. Radio signals are rapidly attenuated in water and the higher the frequency, the greater the attenuation. That's why submarine communication uses very low frequencies. I would have not expected modern 2.4 GHz system to operate at all, unless you have some form of external aerial that pokes above the water.

2.4ghz doesn't work because it's near the resonant frequency of water. You can use 435mhz modules with most modern radio gear. 40 meg and 27meg are more the standard radio gear for model subs.

How about surface boats? Is 2.4ghz a bad idea? I heard many years ago that the boat hobbyists would but up old 27mhz tx's off Ebay as they worked better than the modern stuff, is this correct, and have I got a 27mhz radio in my cupboard that I robbed for spares and turned into junk, that perhaps I should have retained in pristine condition??

wibblywobbly wrote:How about surface boats? Is 2.4ghz a bad idea? I heard many years ago that the boat hobbyists would but up old 27mhz tx's off Ebay as they worked better than the modern stuff, is this correct, and have I got a 27mhz radio in my cupboard that I robbed for spares and turned into junk, that perhaps I should have retained in pristine condition??

2.4ghz is the norm for surface boats, I've never had an issue in all the time iv been using 2.4ghz. Alas 27mhz isn't particularly. Some of the exotic 40meg gear will fetch a decent price because of the submarine lot still using it (and the French I'm told)

Cheers Tom.

Boaty McBoatface back again with more numpty questions.

The kit arrived today, jeez, that's a lot of sprues and parts! Good news is that the hull is one piece and quite rigid, so no gluing two halves together or anything. I just needed to drill out holes for the twin rudders, and the propeller shafts.

I printed a motor mount that will take three spare Heng Long 360 motors, as can be seen in the pic. My question is, if I tilt the motors so that they line up with the shafts, do I still need to install universal joints, or can I get away with a direct link from the motor shafts to the prop-shafts? It will be a piece of cake to get everything perfectly in line but is there something I don't know? Buying the joints isn't a problem, they are pretty cheap, but to my befuddled mind if the whole shooting match is in line then it reduces vibration.

I will be using brass tubes etc, I am using styrene tube just to see what's what.

Hi
Trumpeter are bringing out a 1/48th scale U Boat VIIc should be out soon?. Looking at pictures of it, it has a full interior but you could leave that out!! Arkmodel also have a VIIC out as well. Brian...