HI Len

Like Shipwright i use 2 types cheep chinese esc off ebay, the blue anodised ones, and even with weed round the prop and shaft they didn't get hot.

The other type are Electronize which are about 20 years old and her been hammered over the years with my Huntsman, they have an easy life now in Yorkshireman and Amsterdam. But still don't get hot even on 24volts.

Hope this helps

Mark

Modern ESCs work by switching fully on and off rapidly. Heat is generated as a result of power dissipated in the ESC. When fully switched on, current flows, but no voltage is dropped across the output transistors, so no power, no heat. When fully off, there is no current, so no power, no heat. Most of the heat that is generated happens during the short, but finite, time involved with them changing state between on and off. Since there is yet to be a perfect semiconductor, there is a small loss giving some heating, but if the ESC was properly designed for boat use, the heatsinking provided by the case will be adequate.

For mounting, velcro is good, as is double sided tape pads, as is finding a corner where it can sit comfortably. As long as the fins can have air flow over them. The heat, such as it is, is not going through the mounting, it is headed the other way.

That speed controller shouldn't even get warm with that motor/battery combination. Make sure you buy the self-adhesive Velcro; sewing it to a metal hull isn't my idea of fun.
DM

The motor and esc of my sub gets quite warm..the interior volume is very small and although , as above, the currents and so on are well within the esc spec , there is nowhere for the small amount of heat to go….

Ashley

My calibrated finger is set to 50 degrees. If a component is any hotter than that I need to remove it sharpish. So, if you can hold your finger on the esc heat sink then you haven't much to worry about. I have a very big trainer style aeroplane (84" ws) which I electrified rather than use a noisy, oily .60 size engine (10cc). It draws up to 50 amps from a 4S (14.8v) LiPo and the 60 amp esc barely gets warm. Admittedley, a much friendlier environment than your submarine (the fuselage is spacious) but, provided your esc is used well below its rated current it should be OK. The bargain esc are less capable at their rated current than more expensive ones so my practice is to run them conservatively and arrange for full throttle only to draw a modest current by not overloading it with a big propeller. Remember an that an esc works harder at half throttle than full.

Tempting though it is to attach the esc on the flat side, don't do it. That's the heat sink and needs to be open to whatever air there is around it. If yours is big enough to have a finned heat sink then it's more obvious.

btw, some 2.4 gHz systems (eg Frsky Taranis) have telemetry feedback and temperature is one of the things you can monitor remotely. So if your RC system allows it then it's worth thinking about.

Geoff

I know full-size submarine communication is at low frequencies ( around 200kHz) because of the water effects but I assumed model subs being only just below the surface would be much less susceptible. Don't you stick the antennae up so they pierce the surface?

If there's a 40Mhz JR RF plug-in module it would fit in the Taranis but you'd have to use JR receivers which probably wouldn't have telemetry capability. You need to use 2.4gHz for that and I guess the combination of a metal hull and the water makes it useless for you.

Submarines are a fascinating modelling challenge, I would think. And they sail in 3D like aeroplanes fly in air, with the added difficulty of not being able to see them very well.

Geoff

Kip

320A @ 7.2v = 2.3Kw, or 3.2HP. If you believe that you can put that amount of power through something with cables that thin then you'll believe anything. That said, I doubt if your motor/prop combination would draw much more than about 5A so go ahead, but I'd bet that the low-speed control isn't much to write home about. That's essentially a car speed controller for hot-wound motors and high speeds.
You'd be better advised spending your money on a 'name' brand unit designed for model boats such as Electronize, MTroniks, ACTion or Microgyros. All British-made with proper warranties and service if you ever need it.

Suit yourself, as I usually say.

Dave M

Thanks Dave, thought it had to be a mistype in the amps quoted, which is why I asked, have looked at Microgyros but he's waiting for components to build them, others in the club use MTroniks, so will try one of those.

Ok Dave, thanks for that, we learners have to start somewhere, grateful for those that have & can share.

Oo no, missus! These also reflect my lecture about Chinese amps. I've had maybe six or seven of these handed to me ('ere, clever dick – can you do something with this?) which have blown MOSFETs despite being fused at 15A or less. They are only cheap for a reason – and no, there is nothing you can do with them once the power transistors have blown, apart from using them as ballast. At the risk of being boring, buy a British-made ESC and you'll have the security of a decent warranty and repair/replacement if something does go wrong. Buy everything cheap from China and pretty soon that will be your only choice. Remember what happened to British motor cycles?

Dave M