Friends..Colleagues..modellers..nowadays ECMs are getting inexpensive..and yes, powerful and maint: free, when compared to a Brushed motor..but the sheer power from an ECM never come with ease..it will eat a big ampereage, while running..but my experience shows, that the brushed motors are still good for displacement and heavy crafts, with ease, while eating very less current..so, runs for a long time..and is very easy to make an ESC, with reverse, if we are using a brushed motor..but one of the main problem is with any motor is over heating, especially when use a powerful motor..and usually we looks for some extra ordinary ideas to cool a motor..but here see a simplest possible idea to cool a brushed motor, may be in any size, and type..

yes, i know all you know, but still have some cool simple way..take a drinking straw, a thick one is preffered, or can take copper tube, will be difficult to work, or a body of a ball point pen, anything that feel apropriate, in to a desired length..

fill some fine sand, in to the tube, and heat it up with cigar lighter, and bend it to a l shape..copper or steel must be heated up with gas torch, or on a gas stove burner..

still i preffer the thick straw, because it is very easy to work with..but still works perfectly..

drip out all sands..and cut the bend with a sharp blade in a slanting manner..

this way of cutting gives us a big intake without flanging the tip..

now make an apropriate hole on the bottom side of the hull, just in front, of the prop within arop arch..

insert the sliced tube in the hole, and make a second hole on a convenient place to the side of the hull..connect a silicon tube in between the intake and outlet tubes..

check the water flow, while placing the craft in water and motor at full..adjust the intake tube slightly with fingers untill the flow reaches the maximum level...

now apply glue to the tube, without disturbing its position...

now take a copper tube, in to 5, or 6 according to motor size, can purchased from any A/C, Refrigeration spare dealers, or from a hardware store, costs 15 Rs for a feet..

it is very easy to wind the tube over motor...start to wind the tube around the motor, while keeping a tip in mind about the easiest position of inlet and outlet tubes..

see here how easy to wind it..and please avoid much tight winding, instead leave a card paper thickness all around between coils, because we have to apply the heat sink compound later..

see the simple cooling device..is ready..

fix it on the motor, and root the inlet and out let tubes..seal it with apropriate glues..

apply the heat sink compound, can purchased from any electronic shops, as it is used to seal any gaps in integrated circuit chip installation...its cheap, and costs Rs 10 for a tube..

make sure the inlet tube still in correct position and dried well..

now time for a recheck..make sure the flow is un interupted..and thick at full throttle...Friends..see how easy to make a motor cooler..and works perfectly..when compared to a permenant pump for cooling, here can save battery from the pump motor..and the flow will increase according to RPM..gives us a more realistic feel..and as motor RPM increases it also cooles down the BCM...cool....and using this even on my biggest ships...

yes see the test video here..

Friends..we can cool down anything with this simple idea..ESC..Cards..anything..works nicely..try once..and run your crafts for hours...

Roopesh, brilliant! I love the sand filled tube idea. Brilliant, as usual!

VC Sir..previously was struggling to bend a tube..but later i found this idea..works well..

Pure Genius! These are the small things that set you apart from all of us.

VC Sir..i am only one among you all..i tries some thing like this from the helplesness..at last reach in some good utility..

great innovation sir....

not great..Mase..its simple..but saved lots of my motors...can also cool ECMs..and ESCs..

its..cool..and simple..thank you Sir..

you can also use salt

Saikat..thanks for the idea..

@ Roopesh Sir, Its a very great idea of cooling a brush motor, I missed this before I built my craft.....Will make another one and incorporate the same setup!!!

its all simple but effective..

I will also try in my new craft.....hope i can make it.....
thank you sir.......

lots are on my table unattended.. try when you are here to make own.. 

this is the best method roopeshkrishna sir.

An old method they used on the brushed motors from not too long ago. Less the silicone compound it's not so efficient. This is the first time I've heard of using it and congratulations a great idea but if I may add, remove the unit, clean the silicone off and replace it when cracks are seen or pieces are falling away. Time can dry it out and possibly lose it's heat transfer ability. Vibration would assist in contact being lost.

 With the advent of super powered brushless monsters I have in a number of my boats the motor cooling was achieved with water jackets which did an excellent job as the water actually came into contact with the  motor's casing. Both ends sealed with an appropriate O ring. The interior of the jacket has small specially designed grooves cut into the casing which disrupts the water's passage through the jacket. This stops the water simply going in one side and being ejected immediately from the outlet.

The biggest problem was the ESC. After a few 200 amp units decided to burn out I stripped the heatshrink and used a waterproof sealant over the complete unit and fitted an oversized cooling plate using silicone between the two, then a cut to size aluminium heatsink using more silicone then a CPU cooling fan on the top, using more silicone. The fan was used due to the interior of the boat being an airtight/watertight compartment and it moved the air around  sufficiently to aid the cooling. It was run from an old 3s lipo which would last a complete day's racing before needing a recharge.

One factor I always consider today is a dual water pickup. Twice I have suffered damage from the inlet being blocked by debris so along with the rudder pickup I also use a transom pickup. Both are fed into a y connector which gives redundancy plus the pressure from the single pickup will also blow the debris from the other. I use thick walled nylon tubing to feed the ESC, front motor mount, motor water jacket and then it's disposed of via an outlet just below the upper deck joint. I purposely set the outlet higher as it's easier to spot on the down run. A healthy jet or water shows the system is working well. It sounds like overkill and to a degree is, but when racing the motor's throttle is stuck to wide open even on turns, depending on the course. It's enough work handling the boat without having to worry about cooling. A spotter is often used to check the outlet on each lap.

The extra weight of the cooling system is a small disadvantage and in a few instances has aided certain hulls to a better dryer ride. On a few occasions the hull has turned turtle and the sheer speed has ripped the canopy from it seating. By using conformal spray for waterproofing the boat can be resealed and continue immediately. In fact the ESC will actually still operate under water the sealing is so good.

BUT a BIG word of warning. Use the spray outside with a fan blowing the fumes away from you. They are absolutely lethal. On my first try I had the windows open and a large fan turning. My wife found me passed out after only a minute of starting to spray. I came too OK but had a bad headache for hours after.

Again, please excuse the interuption, maybe someone may find it useful.   Stu

But Krishna, Yoke is with Permanent magnets and coils are inside.
Of course we can make heat flow better by keeping yoke temp low.
But Heat flow from armature to sink (body) is limited by Brass Bush.

That is why BL Motors axle are so large of aluminium for heat flow and mounts are designed for heat sink.

Undoubtedly this is a brilliant and innovative idea, but brushed motors are structurally weak in heat flow. Better connect small fins on commutator that axially flow air through conductor segments of armature at high speed and flow hole in brush assembly and on reverse side too. Though air, but still be cooled directly cool the armature, the main culprit for I²Rt heat.

That is

hello sir how to you make boat prop please put that also iwant to make it

really great sir i wonder if you have any similar technique to cool the car motor.