Schumacher CAT XLS Build - Part 6

 Build Part 6

Radio System, Servo & 540 Motor Installation.

I know, I said I intended this buggy was going to be shelf buggy like my Optima However, I did originally stated, there was a possibility I may run this car.  And the urge to try it is too strong. I need to know how good it really is.  Will it live up to the self indulgent hype, or was I just a crap driver back in the day.

Now, my previous bold claims have given rise to some interesting questions, hence part 6. I claimed many things. To prove some of these claims, I will use a comparison buggy (of the same era) to try and prove my claims. This will be a Kyosho Optima Re-release.

I have run my Optima (in the house) using a 27 turn motor and 27 speed controller (brushed). I used a standard (Tamiya plug) 7.2V, 3000mah nimh battery for power. It was quite quick, not too fast but it is a heavy racing buggy, even with the belt drive option installed (no chain). I will be using the same equipment (on the CAT) for this testing purposes. I will also be weighing both buggies, unladen of all electrical components for a comparison on speed and battery life.

The picture above shows the components I will be installing to run the buggy (I have removed them from my Optima for a direct comparison).

The picture above shows the scales zeroed out with a piece of wood on top to hold the buggies wheels above the bench.

Having removed all of the electronics from the Optima, I can now weigh both buggies for a comparison.

In the picture above we can see the Optima weighing in at 736 grams, which is a lot lighter than I expected.

Next I weighed the CAT. You can see the scales indicating 588 grams. I imagined it would be lighter. However, this does indeed prove the Cat is 148 grams lighter than the Optima.

Equipment to be installed.

The brushed motor I will be installing is an Etronix 27 turn sport tuned motor. The timing on the motor has not been adjusted and is running no advancement of the timing. The picture of the motor below shows wires soldered to the terminals. This was set for the Optima therefore I may have to change the orientation of the positive and negative wires. This motor weighs 117 grams.

For the steering, I will be installing an Altura AAS - 750MG standard size servo. It has metal gearing and a metal 25 tooth output shaft. It weighs 48 grams. Servo speed is 0.14 seconds to 60 degrees at 4.8 volts. The torque of the motor is 10.4kg/cm. Below is a picture of the servo to be installed.

For an electronic speed controller, I will be installing an Etronix ECO 27 Viper. Weighing in at 40 grams, the esc has some good features including, adjustable brakes, adjustable reverse and reverse disable. It has a 3.3khz drive frequency. It boasts of a built in failsafe and being 100% waterproof. This esc is only capable of running a 27 turn motor maximum. As you can see in the picture below, the esc is not exactly small. If you look near the blue wire you can see the programming button. There is also an an LED to confirm your setting that flashes red or green.

I will also be installing a radio and receiver set. I will be installing an Etronix Pulse 2 channel 2.4Ghz radio system. The transmitter is of the pistol grip type with a small steering wheel. On top of the transmitter is a cover that when opened reveals the servo reverse switches and trims for steering, throttle and brake, all standard stuff. What I love about these 2.4Ghz systems are the super small receiver's, as can be seen in the picture below. The small size also means it is very light weighing only 2 grams. The receiver also has a built in fail safe, should your transmitter batteries fail.

Below is a picture of the transmitter. It is quite heavy, with a full compliment of AA batteries, weighing in at a  staggering 329 grams.

Finally we need to get some power to all the systems on the buggy. I will be installing a Voltz brand, 7.2 Volt, 3000 mAh nickel metal hydride (NiMH) battery. This battery comes with a standard Tamiya connector as can be seen in the picture below. The battery is very heavy weighing a massive 203 grams. It is the heaviest component on the buggy.

If I have done my sums correctly, I will be adding 410 grams to the CAT. That is almost two thirds of the weight of the buggy. So the final weight of the CAT  should be 998 grams, whereas the Optima would weigh 1146 grams or 1.14 kilo grams. Therefore the difference in weight would be 148 grams. An expected figure, considering I am using the identical parts that were installed on the Optima.

Thanks for reading.

Please join me in Part 7.

Thanks you for reading and take care my fellow RC enthusiasts from around the World. 

See you soon! 2020