Introduction

During the last few years, the power output and capacity of batteries, the windings of the motors used in competition as well as the electric speed controllers have evolved at an enormous speed.
The constant increase of power, capacity and internal resistance has had the side effect of our motors having higher and higher operating temperatures.
Brushed motors are the main victims of these higher temperatures while brushless motors thanks to their almost frictionless construction, have largely shifted the overheating problem to their ESCs.

So, to counter this climate warming...uhm, no, the warming of our motors, the manufacturers have come to produce full aluminium motor mounts and even radiators with cooling fins to clamp onto the motors.

These radiator clamps have developed and now even a ventilator is mounted on top of them to provide more cooling. These "ventirads", how they shall be called henceforth, are now very commonly used in our cars and have proven themselves useful. But their ventilators are very fragile and need regular maintenance.

The arrival of the TCS - "Thermal Cooling System"TCS - "Thermal Cooling System" marks a new step towards the search of the ultimate cooling for our electric motors and proposes a solution previously unheard of in the area of radio controlled cars.
The motor is no longer air-cooled, but by a cooling liquid which circulates in an on-board liquid cooling system.

In our test we are looking at the version designed for brushed motors. A brushless version that includes a cooling element for the motor and the ESC was announced as well but is not yet available.

Does the TCS bring about a new revolution ? What is it’s effectiveness ? Is it’s installation difficult ? What does it bring in terms of performance and reliability ?

To find out all this and more, read our review of the system below.

Before we continue however, we would like to thank the french TCS distributor, 2LB Racing, who has supplied us with the TCS - "Thermal Cooling System" and allowed us to make the first worlwide review about it.

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1. Presentation

a. The packaging

The TCS is delivered in a small, white carboard box with "TCS" stickers on top and stickers on the side which describe the "Thermal Cooling System" and it’s specs.
The packaging is very neat and seems too small. A picture would have been nice.

b. The bundle

When opening the box, the three key elements of the TCS appear :
 the pump (made of blue anodised aluminium)
 the radiator (made of aluminium, with three heatpipes crossed by cooling finds and blue anodised mounts on two sides)
 the motor plate (made of blue anodised aluminium)

All of it carefully placed in a foam block.

After taking out the foam one discovers the rest of the bundle :
 the coloured manual (in english) with installation recommendations and coloured pictures and diagrams.
 two bottles of liquide (non-conducting)
 one black silicone tube for cutting and connecting the elements of the TSC (it is long enough to outfit two cars with the TCS, and the tube is strong and flexible enough to withstand the RC car environment to which it will be subjected)
 two bottle extensions/pipettes out of silicone to fill and empty the cooling circuit.
 one T tube out of clear silicone to fill and empty the circuit and check the liquid level.
 5 sticker sets TCS - "Thermal Cooling System", two of which were folded because they were too long to fit into the package
 some double-sided scotch tape to mount the pump (and possibly the radiator).
 some tie wraps/zip ties (to possibly mount the radiator).
 two long screws to mount the motor and the motor plate (which is wedged in between) to the motor mount.

The TCS bundle is complete. Nothing is missing for it’s installation. One could only ask for some more examples of mounting the system.

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c. The key elements of the TCS

Let us take a look at the three key elements of the TCS.

1. The pump

The small electric pump is connected to the receiver and according to the provided specifications it consumes less power than a classic "ventirad".
The body of the pump is made of blue anodised aluminium and covered with a TCS sticker.

It’s head features three specific entries and exits, their function being :
 filling the circuit with liquid
 entry of the cooled liquid from the radiator
 exit of the liquid under pressure towards the motor plate

And finally, a blue LED on the foot of the pump which lights up when the pump is active.

Advice

 replace the pump’s connector with a standard connector

2. The radiator

The radiator is made entirely out of aluminium. The central part consists of cooling ribs which cool the heatpipes that run through the radiator and in which the liquid is cooled.
The radiator mounts are blue anodised and feature an entry and exit on either side which can be used in either direction.

3. The motor plate

The motor plate is also made entirely of aluminium. Its exterior is anodised blue.
It features an entry and exit for the liquid which are colour-coded (blue and red) to avoid any inversion.
The plate is very fine and flat, and with the perfect shape of the motor except at the level of the entry and exit tubes of course. It has many holes to fit all kinds of motor mounts perfectly.

d. Specifications

Our measurments of weight and power consumation of the "Thermal Cooling System" :
 pump weight : 11 grams
 radiator weight : 14 grams
 motor plate weight : 12 grams
 system assembled and filled : 47 grams
 power consumation of the pump : about 50mA

e. The choice of aluminium under question

As we already stated, the radiator and motor plate are made entirely out of aluminium.
Aluminium certainly has good thermic qualities, but water cooling afficionados are surprised by the choice because copper is an even better heat dissipator than aluminium.

For me, the choice for making the parts for the TCS out of aluminium is explained by these reasons :
1. The weight difference between copper and aluminium (aluminium is lighter)
2. The higher cost of copper as opposed to alumium
3. The machining of copper is more expensive than aluminium

TCS has chosen to use aluminium for its lower weight and price instead of copper for its optimal cooling capacities. If this choice is justified will be determined by our tests.

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2. How the TCS works

a. Water cooling vs. air cooling

To explain how the TCS works, a little parenthesis into the world of computer hardware is necessary.

Actually, while the TCS is very new to the world of RC, it is not more than, or less than, an adaptation of PC watercooling systems, tailored to the specifics of our discipline.

But let us return to the PC. A PC can be water-cooled for two entirely different reasons :
 to lower its noise emissions (from the ventilators/fans)
 to push its components to their maximum performance (overclocking) while still keeping them stable

Of course it is the second option which interests us. We are not really looking for silence...
The overclockers, individuals on a trip to push their PC to its limit, have proven that a cooling system that employs liquid in a cooling circuit (water cooling) is a lot more effective than air cooling realised through classic "ventirads".

Small explanation

For a normally-used PC, an air cooling system with ventirads is largely sufficient.
But when one overclocks (accelerate its working frequency) one element such as the processor, graphics card or the memory blocks, the heat this element gives off increases considerably and as a consequence it can overheat. It will then work slower or stop working at all or even be damaged.

This is where the water cooling scene comes in. Their miraculous solutions keep these elements cool and at or below normal working temperatures even while increasing the performance of the system to a point mugh higher above manufacturer’s specs.

The designers of the TCS thus set out with the same goal in mind and to reproduce this system for our cars :

Moderate operating temperature = optimal performance

In short :

 Air cooling : Cooling by radiator with or without ventilator, using the air flow.
 Water cooling : More complex but much more effective cooling system based on a hydraulic circuit.

For more information about water cooling :
 Hardware.fr / Le Watercooling facile
 Presence-PC.com / Comparatif de kits Watercooling
 Matbe.com / Refroidissement

b. Small explanation, why does a brushed motor produce more heat than a brushless ?

This small explanation seems necessary to allow all of you to understand why it the TCS in its "brushed" version is so interesting.

We will limit ourselves here to the two primary reasons of the heat :
 The primary reason is the surface for the heat exchange to the air. The windings are on the rotor and they do not have a lot of surface to give off heat to the air. Even though the rotor rotates, it is not a turbine and the air flow in the inside of the motor is very small.
In a brushless motor the windings are fixed to the case and thus they have a lot more cooling area. This is also the reason that a brushless outrunner produces more heat than a our brushless inrunners.
 The second reason is where the electricity flows from the head of the motor via the brushes to the collector. A lot of friction and thus heat is produced here. This effect is also increased when the collector has not been milled down for some time.

c. The cooling cycle of the "Thermal Cooling System"

Here are the three stages of the cooling cycle of our "Thermal Cooling System" :
1. The pump receives the cool liquid from the radiator and directs it towards the blue entry on the motor plate.
2. The liquid circulates through the motor plate and picks up and stores the heat given off by the motor. The liquid is now warm and needs to be recooled. To this end it exits by the red exit of the motor plate and travels towards the radiator.
3. The radiator receives the warm liquid and guides it through its aluminium heatpipes which themselves are being cooled by the aluminium cooling fins that are cooled by the air that travels throug them.
4. Once recooled, the liquid makes its way towards the pump again and then the motor plate.

The cycle is complete.

It has to be added to this explanation that there are two "chimneys" that are mounted vertically on the pump and and in the tube between the motor plate and radiator.
These allow for emptying the circuit and to check for the level of liquid inside the cooling circuit.

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3. Installation

After all this theory we move on to install the TCS which you can see is not very difficult but it needs a bit of effort to think about the organisation and layout of your chassis.

a. The test car

The most-stressed motors and the ones that get the hottest are the ones in 4-wheel-driven touring cars (the main target area for the TCS) and to a certain degree those in 4x4 buggies.

We have decided to mount our TCS for testing onto a touring car, which led us to a small problem as we have two different cars at our disposal at the time :
 a Team Associated TC3 FT
 a Team Losi Street Weabon IWC (the onroad version of the XX4 WE)

Because it seemed impossible for us to mount the TCS to the Associated TC3 because there was not enough room on it, we chose the Team Losi Street Weapon IWC for this test.
This choice also seemed justified as the car was derived from the 4x4 Buggy XX4 which was not particularly known for its effectiveness in motor cooling, and this also allowed us to draw a parallel between the touring and off-road categories.

b. Installation

As already said, the installation of the system is quite simple, but first one has to think about where to place all the elements, and this preparatory phase can be long.

The TCS confronts us with new constraints :
 The pump has to be mounted so the entries and exits point upwards.
 The radiator has to be positioned horizontally so the cooling fins are ventilated optimally. This is one of the most important points and on this hinges the effectiveness of the cooling cycle of the TCS.
 The radiator has to be mounted with the zip ties (the double-sided tape is ineffective, I’ve tested it for you..)
 The entry and exit of the motor plate have to be mounted so they are not obstructed.
 The silicone tube must not be bent too sharply or the liquid will be blocked.
 The transparent T-tube between the motor plate and radiator has to be mounted vertically.

Finally, the tubes circulate through your chassis, and it is very important to organise all the electric leads and cables.

Besides this long and intense thinking process of where to place what, the installation of the system is comfortably easy but attention has to be paid so the silicone tubes do not get pierced when sliding them onto their metal extensions.

On our Team Losi Street Weapon IWC, we have realised two different installations :
 The first one is with the electronics repositioned to the front to offer a maximum of space and ventilation to the radiator of the TCS which was placed on the rear shock tower. This vertical position high up and free has very quickly proven to be ineffective because the radiator did not benefit from a direct air stream to cool the liquid.
 for the second installation, we have mounted the TCS’ radiator horizontally on top of the bumper and have cut out the grill of our Stratus for a direct air flow to the radiator.

It is with this second installation whith which we have performed our test.

Advice

 Before you buy a TCS, make sure it is compatible with your chassis, this is not guaranteed by the manufacturer.
 The rule is simple, the more air flow you can get to the radiator, the more effective the system will work
 The most effective positioning, which we have not been able to do on our car, is to mount the radiator vertically with the most air flow possible. This leaves us two options : At the front with a hole in the body and a place inside the bumper for the radiator, or besides the chassis, where it will be relatively unprotected.
 The space between the pump’s metal extensions is very small and I advise you to first fit the black silicone tubes to the pump before fitting the transparent "chimney" so the black tubes do not get punctured.
 The steel motor screws are very long. Make sure they are not too long and touch the rotor.

And here are the pictures of the results.

The first installation

The second installation

c. Filling up the TCS

Once the "Thermal Cooling System" is in place, you need to fill it up with the supplied liquid which we remember is non-conductive, always reassuring in the world of electric RC.

Filling the TCS up is easy, all you have to do is :
 take the two bottles
 define one bottle for delivery and one for reception
 place the silicone pipettes ontop of the bottles
 loosen the pipette of the receiving bottle to allow the air to escape (or the bottle will expand)
 connect the pipettes to the "chimneys" of the circuit and pay attention to put the right bottle to the right chimney (the delivery to the pump’s chimney, the reception to the other chimney)
 press the delivery bottle for some seconds and repeat to fill up the circuit and evacuate any air bubbles
 once the liquid that comes out into the receiving bottle contains no bubbles, pince the pump’s chimney, take the pipette off and close it
 do the same thing with the other chimney

You’re done !

Attention

 Before every r-n, check the level of the chimneys and in doubt, refill the circuit.
 After the first run with the TCS, the level of the liquid will go down rapidly because the system will transfer all the remaining air bubbles to the chimneys. After the first run it is necessary to refill the TCS.

Pictures of the filling :

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4. Trying out the TCS - "Thermal Cooling System" brushed

Our tests took place at the new indoor carpet track of the MRCI (French RC club near Paris) which was finished in february 2007 which is ideal for touring car testing because it is a relatively quick and technical track on a very tough carpet, in short it makes motors very hot.

a. Configuration

For testing the capacity of our TCS we have chosen two configurations :

Configuration 1

 Chassis : Team Losi Street Weapon IWC
 Motor : Peak Thunderbolt 17x2 on bushings
 ESC : LRP V6
 Batteries : 4200 East Power
 Servo : KO Propo FET 1002
 Radio/Receiver : Sanwa M8
 Tyres front and rear : Take Off with treatment

Configuration 2

 Chassis : Team Losi Street Weapon IWC
 Motor : Peak 12x3 on ball bearings
 ESC : LRP V6
 Batteries : 4200 East Power
 Servo : KO Propo FET 1002
 Radio/Receiver : Sanwa M8
 Tyres front and rear : Take Off with treatment

In short the same configuration for each test except the motor, the goal being to determine the effect of the TCS on the categories "Open" and "Promo".

b. Test protocol

To measure the motor temperature, we have acquired an infrared temperature gun of the type RAYTEM PM 20 whith industrial degree precision.

The temperatures were measured on 3 points :
 the two extremities, the motor mount and head
 the motor case
after five minutes of driving, the duration of an official race.

c. Tests and results

To make it easier for you to understand and interpret the results, we have realised some diagrams and graphics.

a. The temperatures in °C measured on the 3 points of the motor

table of values

graphic

Analysis

The graphics and diagrams above show the same thing, the TCS is efficient in cooling all three parts of our motors which we have measured, but let’s analise the situation further :
 the TCS does not cool the motor parts equally, this effect is the result of the limited temperature exchange of the contact area of the TCS motor plate.
 It is the coldest part of the motor, the motor mount, that benefits the most of the cooling and the hottest part, the motor head, is situated on the other side and so is not cooled as efficiently.
 a clamp- or ring-like solution, as with the ventirads, which is placed on the motor case would have certainly been more effective because of a bigger exchange surface and better positioning.
 on another note, the different temperature gains between our two motors have shown that the TCS is particularly effective on our 12x3 motor and less so on the standard 17x2 motor which does not get nearly as hot. Could this be due to warmer liquid being easier and less warm liquid harder to cool ?
 the efficiency of the "Thermal Cooling System" as determined by this test was to give a temperature gain of 36% or 36°C on the motor mount and 26% or 29° on the case.

b. middle value/average of the temperatures in °C measured on the three motor points

table of values

graphic

Analysis

These new values confirm our initial findings, to know an overall efficiency of the TCS, particularly on our 12x3 motor with 25.38% of average temperature gain, and a reduced efficiency on our 17x2 standard motor with an efficiency of just 13.78% of temperature gain.

b. Temperatures in °C measured on the TCS radiator

table of values

graphic

Analysis

These last values allow us to judge the efficiency of the radiator with our installation and evaluate the difference of temperatures asserted at entry and exit of the circuit.

To remember, the capacity of the TCS to cool the motor hinges on the ventilation of the radiator. These values allow us to judge the efficiency of our installation and positioning of the radiator.

In our case, we have determined with our two motors that the hydraulic circuit of the TCS has cooled as high as 15%. This performance is adequate but not exceptional. An experienced modelist with enough time on his hands could surely improve this performance.

However, this effectiveness of the radiator as determined by our two different motors does not explain the different performence of the TCS measured inbetween the two...

Contribution to performance

And of course, does this decrease of temperature bring a gain in terms of performance ?

Well, with the standard motor, it starts badly, because I did not notice any change in the motors power or performance.
With the modified motor, the TCS brings a small improvement but still not exceptional.

Then, what’s the deal you will ask me ?
Well, there are still drivers whose motors get a lot warmer due to bad ventilation of the chassis and who search desperately for a solution that is more effective than the classic ventirads ; for those, the TCS offers itself as THE solution.

And there are also those drivers that like to push their motors a little bit more but see themselves confronted with the thermic limits of their motors resulting in unsoldering of the wires or literally smoking the engine.

For those, the TCS also brings a certain advantage. Because of the TCS’ cooling capacities the motor runs much cooler in "normal" mode than it used to. This allows you to use this advantage to gear your car longer, if the track permits it. The motor will then certainly get hotter again but it will keep working thanks to the TCS.

Remember the the overclockers and their faster PCs.

Finally, the last advantage of the TCS is good cooling of the motor case which reduces the loss of magnetism of the magnets and allows for a longer case life.

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5. Even more efficiency from your TCS ?

It is possible to increase the cooling capacity of the TCS with two easy tricks :
 the first trick is to mount a small 7.2V ventilator onto the radiator that blows into the cooling fins and onto the heatpipes
 the second trick is to apply a small coat of cooling paste (for example Arctic Silver 5, which you can get at every good PC shop for 5€/5 grams) between the motor and the TCS motor plate.
The cooling paste is designed to smoothen out all the uneven spots between the two connecting elements and allows for a heat exchanging surface close to 100%.

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6. Conclusion

This first version of the TCS has brought a lot of talk with it, and our tests have validated its efficiency in terms of motor cooling.

Also, a lot of good racing drivers have already started to use it.
But this first version is not free of faults and several points of improvement should be considered for the next versions :
 replace the motor plate with a clamp-/ring-style cooling element (like those on the the ventirads) which will improve and centralise the contact surface to the motor
 provide a ventilator to cool the radiator and make its positioning easier
 provide cooling paste to improve the heat exchange between motor and TCS

Also remember that the results we obtained with the TCS in our tests only apply to our configuration. A different installation/mounting on the same car or on another car would have given different results.
These tests have had the goal of verifying the capacity of the TCS to cool our motors.
And even though in our tests we have not seen the 40% of temperature gain as announced by the manufacturer (who did not precise if this is an average value or a single measurement or with which type of installation these results were obtained) we think that after an optimisation of our installation, it would have been possible to gain even more degrees.

Finally, take note that a brushless version of the TCS was announced (with a cooling plate for the ESC added to the bundle) as well as a version for 1/8th gas buggies. [thermique means gas engine, 1/18 must be a mistake ?]

To conclude, we especially reproach the high price of the TCS, which is about 150€, as opposed to classic solutions as the ventirads which are of course less effective but also a lot cheaper. Our second reproach is that it is not compatible with the constrained chassis of most of today’s 4x4 1/10th buggies.

Points +	Points -
Parts and fabrication quality  Conception  Efficiency  Complete Bundle  Originality  Weight, consumation	Price  Exclusivity  Preparation of the installation  Delicate placement of the radiator  Compatibility not guaranteed

Thanks to Jean François for supplying us with the temperature gun and for helping us during our tests.