Transferred this from my build blog. Quick vid of the starting - sound/ smoke /water exhaust sequence (water not plugged in, but can be started a few seconds later than the smoke). Smoke starts first to heat up, then air pump (timer for 5 seconds delay) then water (TX switch,) - could put in another timer to make it fully auto, but enough spaghetti there already. Also handy for future water cooling if the motors need it (fan cooled so probably not needed.) Left stick is held over to start the sequence, then released to turn the smoke and air off.

My Vic Smeed Thornycroft MTB has been sitting in dry dock over the summer, due to holidays but also procrastination due to my fear that when I finally launched her she'd go straight to the bottom...

Anyway, this morning I plucked up courage, took her down to Black Park lake near Slough and chucked her in. She appeared to sit well in the water. I gently engaged the throttle and waved a tearful farewell as she moved off 20 yards or so towards the middle of the lake. I took her round in a wide arc and back to port. I repeated this a couple of times and did some straight runs until the tiller mechanism jammed, fortunately she was within grabbing distance.

I was so relieved and pleased that she worked. She had a good turn of speed (nothing too dramatic) and seemed to steer well, keeping fairly upright.

There appeared to be little if any water ingress. The water cooling system for the ESC didn't work (I suspect kinks in the tube) but it didn't appear to be overheating. I'll attend to that and also the tiller mechanism before I take her out again.

Finally got my sea legs!

Finally got a good day to try the new brushless motor. Boat goes 100% better now (if a bit noisier) 3s 25c 2200mAh liPo got a bit too hot, so probably need to up the C rate to 40 to keep it cooler (maybe install a fan as it's closed under the seat) It's pushing a 6lb boat with a 26mm jet with a 3000kV brushless so it has an excuse to get hot, (only got down to 3.7V/cell after that run, so not too bad). Runs with a more scale look now which is what I wanted. Took a bit of experimenting, but got there in the end. Thermostatic cooling fans for the motor worked well, and within 10 mins the motor was cool. Only used around 2/3 throttle so as not to stress the coupling too much (you can hear it protest a few times, - silicone tube slips slightly making it squeal)- automatic rev limiter😁

Sorry, vid is blurry again ☹️ (original's fine -HD) but something happens when it goes through my movie editor then to YT. Keep procrastinating about getting a better camera (or maybe it's just the editor. - More experimenting, this is getting tedious😐

Fitted a new bottom skin fitting for the water pump pickup(air/water/exhaust smoke system) - removing the pickup from the jet, as flow stopped when the jet stopped. Fitted a new transom skin fitting (RH side transom) for the ESC cooler exit, and took the water from the jet pickup for the ESC cooler. Everything seems to work well now, with the ESC water flow increasing with throttle. Now for a test on a decent day, (has to start with the rain and wind now, doesn't it?☹️)

Set-up pics in blog,

Think I've finally sorted the mixing smoke and water for exhausts problem. Graham has already done his using the same pen / e-cig unit but with some nice electronic controls for the on off system, but not having the electronic abilities I've just gone with a more basic method. Wired up the pen and installed a filler tube (2 tubes are better - one for a breather) these are capped after filling to prevent air getting back from the pump. This system has a water pump, an air pump and the smoke unit, (all adjustable with their own voltage buck) Thanks to Martin for his pen suggestion. I was previously using large capacity elements fitted in various containers for my experiments (truckloads of smoke available) but these pens are great for tight spaces and don't draw much current.

Air, and a small amount of the cooling water are mixed by venturis just short of the exits (the air pushing the smoke and blowing the water clear of the smoke tubes). I've fitted the same system into my ST but am still waiting for the air pump from China (postal system problem there, then Chinese new year holidays with new rules apparently) Get the odd bubble at rest but with the low exhaust you can't have everything.
Latest vid with boat in the tank.

JB

A fan powered smoke unit (modified Heng Long) tried in the HSL. Not particularly good but it's output is reasonably scale(ish). As the fan (12v comp snail fan) just blows into the back of the smoke box without any positive connection, a fair bit of smoke escapes into the engine bay. The fan is hooked up to run with the cooling pump and is left on while running after the smoke (on off remote from the rotary switch) is turned off, and blows the residual smoke from the engine bay out the exhausts.

There are also the 2 small air pumps plumbed into the exhaust outlets via venturi pipe inserts, to blow the water out of the exhausts, (just on the waterline) as any water stops the smoke coming out (surface tension holds it in the pipe). Once I find a decent high volume small quiet air pump, I can do away with these and the fan, which should make things a bit better.
I've ordered some small 12v 40W printer elements to try another smoker idea, but they will be a while coming. Smoke will only be on for startup so shouldn't be too much of a problem.

I've almost become water/vaporlogged/glycerogged with all these experiments, and the other night I actually set off the smoke detectors,- house smells like a glycerine factory for hours afterwards,- but my skin's getting really smooth😂😂😂😂
JB

Made a few mods to the cooling system and was hoping for a quiet day for a video ("yeah right") Too busy watching out for an erratic orange torpedo to have much close up fun! Tried out a few full speed turns with no dramas, sticks like glue with no hint of 'roll out', just a bit of cavitation.

Thought I'd knock up a quick test tank and try the new cooling pipe additions, sound, new ESC fans etc.

Zoom 1 (Interceptor) Mono boat.
Built from a Glassfibre hull, brought on Ebay for £35 the hull is a slim mono racing type with a self-righting side cabin it runs a 1400W 14V 2958 4200KV Brushless Motor and 29-S Water Cooling Jacket with additional air cooling fan.
I did not want to use a flexi drive as high maintenance and prone to failure so the shaft runs via two universal joint one at each end. the propeller is a 38mm copper alloy
The ESC is a 200W and water cooled the twin rudders supply separate water one for the motor and one for the ESC.
The rudder are positioned to reduce prop-walk and are hinged to prevent damage if you hit a object in the water and also for ride adjustment.

Turn fins and trim tabs for ride adjustment were provided by a spares kit for another boat. also foamed and added an inner sealed hatch, a rubber bump strip and safety loop.

Built from a kitishack kit 56" it runs on two Hobby King 750kv brushless motors I used brake pipe to make the motor cooling coils two 200a water cooled esc,s, I got the 5mm shafts & 42mm brass props and couplings from SHG models the power is supplied via two 14.8v lipos this is a really powerful boat

I built this one about 3 years ago she is built at 1/24th scale 50"long and is a plank on frame hull , scratch built using lime wood planking and 9mm ply for the frames and keel, the rest is birch ply of various thicknesses.
she has a 12volt cooling fan motor driving a 4" prop,and has a 12volt 48amp hour battery ,plus some lead for ballast,with working lights and revolving radar scanner

Some more pics of hatch detail and a not to good internal pic.
Torpedo tubes help hide hatch line. Another pic of 0.5 m/c guns shows cooling flutes on barrels.

Graham