All donations are securely managed through PayPal. Amounts donated are not published online.
Many thanks for your kind support.
Model Boats Website Team
January 2018: 18 people December 2017: 7 people November 2017: 13 people October 2017: 9 people September 2017: 15 people August 2017: 10 people July 2017: 16 people June 2017: 8 people May 2017: 4 people
Dave M is right, but, if you have the 46" hull at slow speeds you might find a lack of cooling, due to the long distance to the motor's, a pump will cure this, but, look for a low watt pump, 10 L PM will be fine. I like my outflow at the stern as the exhaust but it can be masked with the propwash Mark
Thanks for yet more good advice, Dave M . I will try 20-25 amp fuses to start with. As it happens, there is the original ic water cooling system still in the hull, kept for realism but I could easily make it functional.
Hi Doug Brushless melt when stalled if you are lucky. No fuse and high power battery usually results in the ESC also melting or a small fire that usually quickly spreads to the rest of the model. Not sure if I would go much above 25 amps on a 50 amp ESC, most are overated and will probably need watercooling at full capacity.
Hi Granpa, There are 3 dealers in Canada (see first pic). Aero-naut has 7 model outboards. The pics show the 2 smallest, with part numbers. Please note: They are sold without props or motors but with coupling for 4mm shafts. Here you can see the specs / dimensions of all variants http://www.aero-naut.de/produkte/schiffsmodellbau/schiffsant... The 'Retro' versions on this page come complete with in-runner motor and water cooling. The Aqua Race mini complete with motor and prop is probably the one for your skiff! Happy hunting, cheers Doug 😎
Hi Pilot If you are using 540 can size (35-36mm brushless motor) a 3639-1100kv 800watts, 3648-1450 1600watts or a XK 3674-1900 1769 watts. All run on 100Amp ESCs, but check the maximum voltage they handle. I use car ESCs with the electric fan on top because they run cooler at slow speeds and no water plumbing required. The same with the motors no cooling. Props for these motors 37mm 2 blade or 40-45 mm 2 blade. If you go for a larger motor for a larger prop, a L5055-700kv 1600watts same ESC, but, start with a 2 blade prop about 52mm. Battery a 3-6S 5800mah or more with a C rating of 40 plus. I have used the 35mm motors in 34 to 40" boats, but, for my 46" Vosper Crash Tender I am going to the 5055. To large a prop will cause over heating of the ESC, battery and Motor. A in line amp meter(Hobbyking 9598000004-0) is the one in use. It reads the maximum amps, so for run speed amps slow speed up to maximum as a hit the throttle hard will give you maximum amps. Canabus
[Score: 8/10] 37"/3600g ILLINI NATIVE Capable of 10mph and a runtime of 45mins Twin Propellors (5 Blade 50mm) Direct Drive to a 775 JOHNSON TYPE (5 Blade) Powered by NiMH (8.4v) 3Amp/h Batteries Controlled Through DIMART FAN-COOLED 320A 6-18V (10Amps) ESC - Comments: DUMAS AMERICAN BEAUTY TOWBOAT KIT; 35X9 INCH ABS "HYDRODYNE" HULL TOPPED WITH BIRCH PLY AND BASSWOOD SUPERSTRUCTURE. SHE IS GIVEN THE ILLINIWEK MARINE SCALE SHIPYARD PAINT SCHEME, THE DECK IS COVERED BY 3/16" BASSWOOD SCRIBED SHEATHING PROTECTED BY MINWAX POLYURETHANE. SHE FEATURES FLANKING RUDDERS WITH RIVABO 5-BLADE BRASS WHEELS, TWIN 1.5V WORKING RADAR ARRAYS, TWIN 6V WORKING DECK CAPSTANS, 9V LED NAV LIGHTS WITH AMBER DECK STANDING LIGHTS AND DUAL BRUSHLESS VENT/COOLING FANS ON THE INBOARD SIDE OF THE FUNNELS (FOR THE FUN OF IT). SHE IS THE SECOND ADDITION TO THE ILLINIWEK MARINE RC FLEET SHE'S PUSHING AHEAD A SET OF DUMAS 1:48 RAKE BOW & BOX BARGES ACROSS THE WINDING CARPET RIVER
before you fit a water cooling system try a smaller prop. You need to think of the gearbox in a car. Too big a prop can be looked at as being like trying to drive off in top gear! A smaller prop will allow any given motor to spin faster and strange as it may seem use LESS not more current. If you keep the drawn current down to the limits set by the motor constructor then its probable you will need no extra cooling. If the boat moves faster than you want use the throttle its what its for. Throttling down also extends battery life. The air intakes on boats like this were intended for IC engines and they NEED air to work.
Ran the model again Sunday for the last time this year, proved well with a little ballast added. After 15 minutes of running checked the temps on the motor, Only just detect the suggestion of warming up, being such a cold day. The water cooling scoop has not been added as yet. Maybe not even needed at all. Hope to continue to source / make the fittings oven the coming months with the boat show Saturday perhaps for a new LiPo battery.
Hi Richard, with a bigger motor and smaller prop you may not need the water cooling, none of my boats have cooling, what i would say is that switching to a gel battery will be heavy, stick with your 7.2v batteries and give it a try, it might last a bit longer but with your twin battery set up you will get about the same run time. Mark
for the purpose of testing, don't go out and buy expensive props, just buy cheap plastic two blade ones, I always use "x" blade, they are a coarser pitch, "s" blade are less pitch. Get a few to test, 35mm, 40mm, 50mm. Fit, short run, see how hot things are. Whilst you don't want to go fast, don't forget this is a big heavy old girl, its better to be overpowered than under powered. If it was me, I would get a graupner 700, watercool with a cooling coil, probably settle with 45 to 50mm two blade "x" prop, run on 12v, this will give some speed and durability. Don't assume that just because the model shop suggested it, its the holy grail, many many times we have seen evidence of very poor advice given by so called experts😡 https://www.ebay.co.uk/itm/Graupner-Speed-700-Turbo-Electric...
the scoop should be fitted behind the prop so prop wash is driving water through it whenever the motor is running and the cooling coil fits around the motor join the two up with fuel tube etc. then the other end of the coil connect to an outlet ( unless you want a self filling boat) http://www.cornwallmodelboats.co.uk/acatalog/ style='background-color:yellow;'>cooling-coils.html http://www.cornwallmodelboats.co.uk/cgi-bin/sh000029.pl?REFP... style='background-color:yellow;'>cooling%2dcoils%2ehtml&WD=scoop%20water&PN=water_cooling%2ehtml%23aG1427#aG1427 As to sitting on your boat you could put it in the water and get some one to hold it while you run the motor up and watch the current used. closing off the cooling vents to an electric motor not used in a speed model shouldn't be any problem if you have the correct prop an electric motor should only get hand warm. The temps you indicate would have burned out your motor even if there had been no covering over the motor at all. With an electric ( brushed) motor the more you load it the higher the current flow and the hotter it gets. Stall current tend towards infinity you have what I think is a 60mm prop and that's a BIG prop being 3 bladed makes the situation worse since there is increased blade area against a 2 bladed prop. If you intend to use that prop then get a motor man enough to swing it.
Hi reilly4 I do not think it is as large as 60mm as it is a three bladed prop, if it was a two bladed one I would agree with you as the blades would be directly opposite each other hence 60mm, but being 3 bladed they are not 90 degrees to the centre point, without taking it off and drawing a circle around it to measure I would hazard a guess it is a 30mm prop. If memory serves me correctly the late Swindon Model Shop which was run by Yan who knew his stuff recommended the 540 motor along with the prop for the size of the boat. I will check the Sea Commander plans as I think it has the size of the required prop listed. Haverlock the motor is rated 4.5 to 15 volts and the battery is 7.2 volt, I would have to run the boat in water to see what the motor is drawing under load, I may get a tad wet trying to keep up with it to read an amp meter, or sink the boat by sitting on it😉 I think the overheat problem was to do with the motor mounting braket covering the front air slots on the motor. However I have a water scoop which I did not fit at the time of building so may retro fit and buy a new motor set up for water cooling, the next question would be where abouts do I fit it?
At the risk of being repetitive get yourself a watt meter that way you can see how much current your motor is drawing. If a motor overheats you are either running to high a voltage or to big a prop. If you are intending to push the envelope you can buy a cooling coil to fit over your brushed ( or inrunner brushless) motor and use a water scoop thus water cooling your setup.