Let’s face it, waving your arms around in front of your Xbox360 Kinect or wiggling that Wii Mote and tilting the crap out of your iPhone might be fun for the first ten minutes. But seriously you can’t play a descent race car or motocycle simulation racing game that way. It just does not give you enough control and is often not accurate enough.

I am not a big handheld gamer – actually I am not much of a gamer lately at all. I am still waiting for the nerve feedback system or the Equilibrium attachment that you stick in your ear so you can experience true motion in games. What’s really missing in racing games though is that kick in the guts, that “oh my god” my head is falling off during cornering and that rare sensation when shifting gears becomes a work out during extreme acceleration. The little rumble of the force feedback controller has a long ways to go…

Anyway, back to the problem on hand. Racing games are fun and motion controls suck.
Solution: Build a Steering Wheel for the iPhone or iPod. Thank god for Lego Technic…

Racing Steering Wheel and and iPhone/iPod Device Holder Front View:

Racing Steering Wheel and and iPhone/iPod Device Holder Side View:

Racing Steering Wheel and and iPhone/iPod Device Holder Rear View:

I tried different size steering wheels – bigger ones don’t look as good but tend to offer more control. Another advantage of using Lego Technic to Prototype this is that I am able to change the gear ratio as well.

Some of you may remember the old Sega “Hang On” Arcade Game – hint the one with the cool full size red bike.
Anyways that inspired my iPhone Motocycle simulator attachment. Not fancy, but makes me smile and works rather well ..just to bad it is not red and they don’t have a port of “Hang On” in the App store.

And of course the whole steering stand motion unit or whatever it should be called can also be used as Surfboard, Snowboard or Skateboard game simulator.

What’s next?
The current setup makes it a bit hard to use the touchscreen while driving. Most racing games offer some sort of acceleration or brake assist but those are limited and a bit lame. I will revisit the project and figure out a way to add gas and brake pedals. Of course the tricky part is that the entire screen moves and the contact (touch) points for gas and brakes move up and down. …we’ll figure it out.

Aside from being a lot more fun it actually makes racing games such as Moto GP, GT Racing etc a lot easier to play.

The platform is build on just a few lego technic pieces. I was not going for prettiness or fanciness – I was just going for function.

I found the Subaru Blueprint a long time ago on the web  – not sure who deserves the image credit. If anyone knows let me know.

Of course it wouldn’t be any fun without modifying a few things. So I added some LED lighting an LCD display hooked up to an Arduino and computer based lap and race timing system triggered by photo transistors in the track. The track power comes from a lap power supply allowing for more control over vehicle speeds. The stock Carerra GO slotcar hand controllers have been replaced with 1980′s Carerra Servo 140 controllers which where much much higher quality and allowed for much more precision.

Considering that I am getting to the age where I value a good comfortable chair, I decided not to put the track onto the floor but clean off the desk and build a little extension with a piece of shelving wood and a 2×4 for legs. The result is lethal for cars that fall of the track, but a really awesome point of view to drive the cars on (almost) eye level.

The lap timing is done via Photo transistors that sit inside the track (yes you just drill a hole into your track). This allows lap times for each car independently rather then my original laser based setup. Here is a post with more details on the RC car and Slotcar lap timer setup. The photo transistors need a good amount of light (unless your are using InfraRed LED’s) anyway I settled for “lot’s” of led’s cause it looks cooler anyway. I also have an Arduino and a 20×4 LCD screen, which I decided to mount on top of my lighting structure. The LCD and arduino are currently purely cosmetic and just display a Welcome message and Driver names and lane information. The actual starting and timing is handled be a laptop PC. Of course the Arduiono could do the timing easily. The structure is build out of Lego Technic pieces – which is by far my favorite prototype platform for structural needs as seen here with my RC Rally Car lights.

I also added some yellow flashing warning lights for “Full Course Caution” – hence the small 3 volt battery pack and the back of the starting tower. Also in the picture below is the Arduino and the back board of LCD117 screen.

The cat (Boris) got really bored during the build process. Which means if you have a hyper active cat you may want to consider taking on a playing with Arduino’s, LCD screens, LED’s and start “hacking” your kids other remote controlled and electronic toys. This will put every cat to sleep.

Here is the final setup of the start/finish lane at night. Note all pics are taken with an iPod touch. I found the iPod touch camera (same as iPhone camera) super convenience for taking project progress pictures. You can email the images to yourself and the image resolution and size is great for blogging. Most point-and-shoot cameras (even the cheap ones) output huge files which means you need to resize and you need to connect the chip to your computer to get the pics in the first place.

All systems go – ready to race. Yet another Saturday well spend by “unnecessary complicating toys”.

Yes that is Formula1 speeds – to avoid confusion, the rally cross car (which is different then a WRC rally car) is much lower geared and will not reach the top end speeds of an F1 car. However up to 60-70mph the Rally Cross car would be neck on neck with an F1 car before the rally car reaches the end of it’s gear ratios and the F1 car would pull away.

Those numbers are impressive, but what does it really mean? How far and how many feet or meter does such a car travel until it reaches 60mph or 100kmh ? And how does that compare to a Remote Control Rally car?

Here is the formula (mathematical equation) to calculate the distance the car needs to travel based on us knowing how many seconds it takes to reach 60mph or 100kmh.

Disclaimer: The equation assumes a constant acceleration curve – a “real” cars acceleration curve is not constant due to gear shifts and torque/rpm ratios.

Here is the Formula:

D = ((VF + Vo) * t) /2

D = Distance | VF = Final Speed | V0 = Initial Speed | t = Time elapsed

We know that the WRC Rally car needs 4.8 seconds for 0-60mph or 0-100kmh

D = We want to know | VF = 60mph or 1/60 miles per second | V0 = 0 mph | t = 4.8 seconds

D = ((0 + 0.01666666) * 4.8) / 2 = 0.04000 miles

D = 0.04000 miles = 211.20004 feet = 64 meters

Answer:

The WRC car will have traveled 211 feet or 64 meters before reaching 60mph or 100kmh

A 1/10 scale RC car should consequently need 21 feet or 6.4 meters to reach 6mph or 10kmh

Likely your RC car is much closer to the Rally Cross or Formula 1 car – do the math and be amazed a Rally Cross car or Formula 1 car will have likely reached 60mph or 100kmh before it reached the end of your driveway or backyard…!

….if you are really serious then there is no way around investing in a nice regulated multi-voltage and adjustable current lab power supply. Here are some Google results in case you are not sure what those are. Obviously those are superior to any homemade or DIY power supply.

But let’s say you need a cheap 12Volt supply to run your DC rc car charger or maybe you build your own RC track and you want to add some low voltage lighting. In this case you don’t want to expose your $300 regulated lap power supply.

Easy solution – build your own 12 volt power using an old Xbox 360 power brick!

An Xbox360 power supply can be easily found on ebay for cheap. However you will notice that when you measure the contacts that your meter reads 0 (zero) Volt. That is because the 360 power supply has a stand-by mode.

1) To remove the Xbox360 stand-by you simply need to open the power supply  – you will find 4 screws under the rubber stoppers/pads).

2) You will see a red and blue wire. Now you have 2 choices. Option 1) Add a switch in between the red and blue 2) Just connect red and blue together (short them out) and your 360 power brick will always be on when plugged in.

3) Next remove the positive and negative cables and solder your own cables in place.

You can purchase pre-build lighting sets from a lot of manufactures – which offers an easy way to get you started. Alternatively you can build your own lights for a fraction of the cost and likely with a lot more output and brightness. In my previous post I build headlights for my Tamyia DF03RA Subaru Rally car. The next logical step is to add rear lights and brake lights.

The rear lights are rather straight forward – just get some red LED’s wire 2 (one for the left side and one for the right) in series and add a resistor in series to not fry them when connecting to your rc cars battery. Remember LED’s always need a resistor and the size depends on your LED.

Building brake lights for your RC car is a bit more tricky. Most commercial rc car brake light kits only come on when you are actually pulling the trigger backwards into braking position. This may work for some but not for me (and the rest of our RC Rally Group) who races on nicely flowing backyard rally tracks (we have 4 on Maui/Hawaii  now) where we do not really use the brake but go off the throttle a lot and coast through corners. Slamming on the brakes on a gravel – loose soil track would unsettle the car way too much. Plus the drag of the rc car motor acts as brakes anyway.

My solution to the “brake lights on” when off the throttle and slow coasting is to use a Zener Diode attached to the motor plus lead (important this only works with brushed motors) and to have the breakthrough voltage of the Zener Diode activate a transistor which will essentially offer the electrons a way of less resistance and therefore turn off the brake lights. Or in other words – the rc car brake lights are on when the car is at a stand-still and will remain on until 4 Volts a measured at the Motor Positive lead. The 4 Volts are the breakthrough voltage of the Zener Diode. When I go off the throttle the voltage at the Motor positive lead falls under 4 Volt and the brake lights come on again.

Below is the circuit diagram which makes the brake light switching a little more visual.

Important Notes:

• Works only with Brushed Motor
• Resistor R1 protect the Zener Diode
• Use a bigger (higher Voltage) Zener Diode to have the brake lights come on earlier.
• Resistor R3 needs to be bigger then R2
• Resistor size for R2 and R3 depends on your LED voltage and current

Picture of RC car brake lights on under coasting and when going off the throttle:

Ever since we started Rally Cross racing our RC cars in our homemade backyard Rally tracks we knew that we had to race in the dark at some point. If you are following my blog you may know that I am not a big fan of buying off-the-shelve products to solve those fun engineering challenges.

The first stage in my RC car Rally Lights project was to build a simple prototype LED headlight array that would attach easily to the car. I opted to use Lego Technic pieces because 5mm LED’s fit perfectly. Plus if you drill out the pieces just a little bit you will find that they fit very nicely onto standard body mounting posts.

This LED Remote Control Car headlight array connects to the cars main battery and uses 6 White 5V LED’s. 2 Led’s are wired in series with a 100Ohm resistor for each of the three pairs. The setup is a bit on the “hot” side as far as the resistor size goes, which means the LED’s may not live as long as they could if they had a bigger resistor. I also added a simple on-off switch.

As mentioned I opted to mount the lights on top of the car so that they can be easily removed for day time racing. Another advantage of clipping the lights onto the body mounting posts is that the lights don’t vibrate and flex as much as they would be when mounted to the lexan body itself. Although, I must say that my friend running an HPI Rally car had his lights mounted into the body and the vibration was not as extreme as I expected.

If you are owning a Tamiya DF03RA Rally kit you will receive nice reflectors and masking stickers that allow your car to have very nice very nice integrated head and taillights. However, the Tamiya stock setup only allows for 2 lights and the lighting kits sold in stores tend to be more for looks then for actual racing in complete darkness. I tried keeping my lights brightness and range to scale – based on the Subaru night super stages lights that attach to the hood for the Australia and Sweden rally, however first tests show that I have to go above scale with brightness to make the RC car really usable on a tight track at night.

My next project will be to add brake lights and tail lights. If you buy a brake light kit for your RC car you will notice that the lights only come on when you are actually using the brake on your radio control, however if you are using drag break with your brushless setup or are using a brushed motor with a bit of drag you may never use the brakes – especially when driving on a nice flowing rally or rally cross track like we build. What I will do is design a circuit that will look at throttle and motor rpm’s and trigger the brake lights accordingly.

Image below shows the front driver cabin. The the left is the circuit board for the Flashing Hazard and Warning Lights and in the middle is the Futaba Receiver for the drive, steering and crane turning control.

Image below shows a panoramic side view of the lego crane.

Image below shows crane operator seat with RC Servo in the background to control the crane arm up and down and hook up and down gears.

Image below shows 2 RC Servos for crane arm, extension and hook control, older Lego Mindstorm gear motor to power the crane unit, old Lego light and sound lights (red) to indicate power to the motor, as well as the 2nd Receiver, Battery pack (empty) and ESC (Electronic Speed Controller) for complete control via Radio over the Lego Mindstorms motor. The very rear show a yellow LED that will flash while operating the crane.

Image below shows front view of motorized crane with raised crane arm

Read more about Radio controlling the Lego crane here..

Here is the Video:

For Christmas I received the LEGO 8053 Technic Mobile Crane which right out of the box is already awesome. It got all-wheel steering (8 wheels) and a really cool gear selection setup to control the crane arm to go up and down and extract, in addition to powering the hook winch.

During the building period between Christmas and NewYear (yes I actually took my sweet time rather than rushing through it) it became clear to me that this Lego model just beckons to be remotely controlled in some shape or form.

Of course it is easy to just go online and order a bunch of motors – Lego has some really awesome motors these days for their MIndstorm and Technic Models. But spending money felt like cheating. So I decided I will make due with whatever parts I have…

Thank goodness I held on to my old Futaba F14 radio from way back when. By the way I recently found out that rather then buying the super expensive MultiProp or MultiSwitch adapters and extensions you can simply use a 5K Ohm Potentiometer to control a channel. Which by the way if you open most rc radios is what you will find in there – cheap potentiometer.

I also held on to the grey little gear reduction motors that came with one of the first Lego Mindstorm kits. Unfortunately I have only 3 motors. But the functions I wanted required a bunch more. Time to get creative.

List of simultaneous functions for my Lego Technic Crane:
1) Drive Forward and Reverse
2) Steer Left and Right – 8 wheel steering
3) Turn the entire crane unit 360degrees
4) Arm Up and Down
5) Arm Extension In and Out
6) Hook UP and Down
7) Sidepods In and Out

Long story short I ended up rebuilding the entire crane from scratch.
I decided to keep the Crane unit and the Chassis completely separated to allow for 360 degree turns of the crane unit.

Problem was that I had three motors but only 2 ESC( Electronic speed controllers), what I decided was to use one servo to trigger a microswitch which in turn switches the output of my ESC between 2 motors.

A) Servo 1 – Steering
B) Servo 2 – Switching Gears between Arm Up and Down and Hook Up and Down
C) Servo 3 – Arm Extension In and Out
D) Servo 4 – Activates microswitch for ESC toggle
E) Motor 1 – Driving Forward and Reverse
F) Motor 2 – Rotate Crane unit
G) Motor 3 – Power Arm, Hook and Extension

I also had some small lightbulbs – I know these days we use LED’s which by the way 3mm LED’s and Lego’s are a match made in heaven.

But why not use up what you have. I also found an old blinking module, which I worked into using as my hazard lights. I further found an old Birthday card which had tiny flashing LED’s which turned out to fit perfectly into Lego’s clear yellow bricks for warning lights.

This was without a doubt the most complex Lego project of mine so far. Lego Technic RULES!

Concept:
2 IR Detector’s connected to an Arduino Microcontroller listen for 10 pulses from a TV remote coming at 38khz to avoid sun light interference.
If 10 pulses are counted then the Arduino will blink the LED’s 3 times. This tells the racer that the TV remote signal has been received.
A short delay gives time to store the TV remote and to focus on the actual Race start.
The start sequence works similar to an F1 or German Touring Car start. The LED’s come on one at a time with a short delay and go all out at the same time which is the start of the race.
The Arduino resets after the start sequence and waits for 10 pulses again to start the next starting sequence.
Due to the fact that the IR LED’s are pulsed they can be “over driven” as far as current goes – which is the reason why a TV remote works from easily 20-30 feet away.

Video:

Items List:
LED’s
220Ohm Resistors (one for each LED)
Arduino Microcontroller
IR Detectors 38Khz
Costco Apple Packaging
9 Volt Battery
20 or 18 Gage Cable

Tools:
Drill
Soldering Iron
Hot Glue Gun

Total Cost: $40
Time: 4 hours

If you are an Arduino Expert or if you are a “Real” Programmer you will probably get a good laugh out of my code. But hey it works.
I noticed that when I run the Arduino on Battery it tends to pick up noise from the IR Detectors. I was trying to let it time out – say if there is no second pulse detected after 1 second ignore the first pulse cause it is likely noise. Unfortunately I did not get it to work. So instead I have it programmed that it needs to see 10 pulses from the TV remote before a starting sequence is initiated. The Serial print commands helped me during the build and for troubleshooting. They are not essential to the function of the race starting lights.

Here is the complete Arduino Code:

//F1 Style Starting Lights

// Set pin numbers:
const int ledPin2 = 2; // LED 1 connected to digital pin 2
const int ledPin3 = 3; // LED 2 connected to digital pin 3
const int ledPin4 = 4; // LED 3 connected to digital pin 4
const int ledPin5 = 5; // LED 4 connected to digital pin 5

const int ledPin6 = 6; // LED 5 connected to digital pin 6
const int ledPin7 = 7; // LED 6 connected to digital pin 7
const int ledPin8 = 8; // LED 7 connected to digital pin 8
const int ledPin9 = 9; // LED 8 connected to digital pin 9

const int buttonPin = 12; // IR Detector connected to digital pin 12
const int ledPin = 13; // Onboard LED flashes when IR Detector sees beam & stays lit for entire loop

// Variables that will change:
int buttonPushCounter = 0; // counter for the number of button presses
int buttonState = 0; // current state of the button
int lastButtonState = 0; // previous state of the button

const int flasher = 200; // Delay of 250 mili seconds for IR signal detected & start sequence initialised
const int ready = 3500; // Delay of 3.5 seconds mili seconds before start sequence
const int timer = 1500; // Delay of 1.5 seconds between starting lights

void setup()
{

// Initialize the LED pins as an output:
pinMode(ledPin2, OUTPUT); // Sets the digital pin as output
pinMode(ledPin3, OUTPUT); // Sets the digital pin as output
pinMode(ledPin4, OUTPUT); // Sets the digital pin as output
pinMode(ledPin5, OUTPUT); // Sets the digital pin as output

pinMode(ledPin6, OUTPUT); // Sets the digital pin as output
pinMode(ledPin7, OUTPUT); // Sets the digital pin as output
pinMode(ledPin8, OUTPUT); // Sets the digital pin as output
pinMode(ledPin9, OUTPUT); // Sets the digital pin as output

pinMode(ledPin, OUTPUT); // Sets IR check LED digital pin as output

// initialize the pushbutton pin as an input:
pinMode(buttonPin, INPUT); //Sets the digitalpin for the button as input

// initialize serial communication – only used for troubleshooting
Serial.begin(9600);

}
void loop()
{

// read the IR Detector input pin:
buttonState = digitalRead(buttonPin);

// compare the buttonState to its previous state
if (buttonState != lastButtonState) {
// if the state has changed, increment the counter
if (buttonState == HIGH) {
// if the current state is HIGH then the button
// wend from off to on:
buttonPushCounter++;
Serial.println(“on”);
Serial.print(“number of button pushes: “);
Serial.println(buttonPushCounter, DEC);
}
else {
// if the current state is LOW then the button
// wend from on to off:
Serial.println(“off”);
}
}
// save the current state as the last state,
//for next time through the loop
lastButtonState = buttonState;

// turns on the LED 13 and Starting Lights every 10 button pushes by
// checking the modulo of the button push counter.
// the modulo function gives you the remainder of
// the division of two numbers:
if (buttonPushCounter % 10 == 0) {

digitalWrite(ledPin, HIGH);

{
if (ledPin == HIGH);
{
Serial.println(“High”);

// Confirm buttonState HIGH by flashing all LED’s 5 times
digitalWrite(ledPin2, HIGH); // sets LED 1 on
digitalWrite(ledPin4, HIGH); // sets LED 2 on
digitalWrite(ledPin6, HIGH); // sets LED 3 on
digitalWrite(ledPin8, HIGH); // sets LED 4 on
delay(flasher);
digitalWrite(ledPin2, LOW); // sets LED’s off
digitalWrite(ledPin4, LOW);
digitalWrite(ledPin6, LOW);
digitalWrite(ledPin8, LOW);
delay(flasher);
digitalWrite(ledPin3, HIGH); // sets LED 5 on
digitalWrite(ledPin5, HIGH); // sets LED 6 on
digitalWrite(ledPin7, HIGH); // sets LED 7 on
digitalWrite(ledPin9, HIGH); // sets LED 8 on
delay(flasher);
digitalWrite(ledPin3, LOW); // sets LED’s off
digitalWrite(ledPin5, LOW);
digitalWrite(ledPin7, LOW);
digitalWrite(ledPin9, LOW);
delay(flasher);
digitalWrite(ledPin2, HIGH); // sets LED 1 on
digitalWrite(ledPin4, HIGH); // sets LED 2 on
digitalWrite(ledPin6, HIGH); // sets LED 3 on
digitalWrite(ledPin8, HIGH); // sets LED 4 on
delay(flasher);
digitalWrite(ledPin2, LOW); // sets LED’s off
digitalWrite(ledPin4, LOW);
digitalWrite(ledPin6, LOW);
digitalWrite(ledPin8, LOW);
delay(flasher);
digitalWrite(ledPin3, HIGH); // sets LED 5 on
digitalWrite(ledPin5, HIGH); // sets LED 6 on
digitalWrite(ledPin7, HIGH); // sets LED 7 on
digitalWrite(ledPin9, HIGH); // sets LED 8 on
delay(flasher);
digitalWrite(ledPin3, LOW); // sets LED’s off
digitalWrite(ledPin5, LOW);
digitalWrite(ledPin7, LOW);
digitalWrite(ledPin9, LOW);
delay(flasher);
digitalWrite(ledPin6, LOW); // sets LED’s off
digitalWrite(ledPin7, LOW);
digitalWrite(ledPin8, LOW);
digitalWrite(ledPin9, LOW);
delay(flasher);
digitalWrite(ledPin2, HIGH); // sets LED 1 on
digitalWrite(ledPin3, HIGH); // sets LED 2 on
digitalWrite(ledPin4, HIGH); // sets LED 3 on
digitalWrite(ledPin5, HIGH); // sets LED 4 on
digitalWrite(ledPin6, HIGH); // sets LED 5 on
digitalWrite(ledPin7, HIGH); // sets LED 6 on
digitalWrite(ledPin8, HIGH); // sets LED 7 on
digitalWrite(ledPin9, HIGH); // sets LED 8 on
delay(flasher);
digitalWrite(ledPin2, LOW); // sets LED’s off
digitalWrite(ledPin3, LOW);
digitalWrite(ledPin4, LOW);
digitalWrite(ledPin5, LOW);
digitalWrite(ledPin6, LOW);
digitalWrite(ledPin7, LOW);
digitalWrite(ledPin8, LOW);
digitalWrite(ledPin9, LOW);
delay(flasher);
digitalWrite(ledPin2, HIGH); // sets LED 1 on
digitalWrite(ledPin3, HIGH); // sets LED 2 on
digitalWrite(ledPin4, HIGH); // sets LED 3 on
digitalWrite(ledPin5, HIGH); // sets LED 4 on
digitalWrite(ledPin6, HIGH); // sets LED 5 on
digitalWrite(ledPin7, HIGH); // sets LED 6 on
digitalWrite(ledPin8, HIGH); // sets LED 7 on
digitalWrite(ledPin9, HIGH); // sets LED 8 on
delay(flasher);
digitalWrite(ledPin2, LOW); // sets LED’s off
digitalWrite(ledPin3, LOW);
digitalWrite(ledPin4, LOW);
digitalWrite(ledPin5, LOW);
digitalWrite(ledPin6, LOW);
digitalWrite(ledPin7, LOW);
digitalWrite(ledPin8, LOW);
digitalWrite(ledPin9, LOW);
delay(ready);

// Turn LEDs on – initiate Starting Sequence:
digitalWrite(ledPin2, HIGH); // sets the LED 1 on
digitalWrite(ledPin3, HIGH); // sets the LED 2 on
delay(timer); // waits for 1.5 seconds

digitalWrite(ledPin4, HIGH); // sets the LED 3 on
digitalWrite(ledPin5, HIGH); // sets the LED 4 on
delay(timer); // waits for 1.5 seconds

digitalWrite(ledPin6, HIGH); // sets the LED 5 on
digitalWrite(ledPin7, HIGH); // sets the LED 6 on
delay(timer); // waits for 1.5 seconds

digitalWrite(ledPin8, HIGH); // sets the LED 7 on
digitalWrite(ledPin9, HIGH); // sets the LED 8 on
delay(timer); // waits for 1.5 seconds

digitalWrite(ledPin2, LOW); // sets the LED 1 off
digitalWrite(ledPin3, LOW); // sets the LED 2 off
digitalWrite(ledPin4, LOW); // sets the LED 3 off
digitalWrite(ledPin5, LOW); // sets the LED 4 off
digitalWrite(ledPin6, LOW); // sets the LED 5 off
digitalWrite(ledPin7, LOW); // sets the LED 6 off
digitalWrite(ledPin8, LOW); // sets the LED 7 off
digitalWrite(ledPin9, LOW); // sets the LED 8 off

{
if (ledPin9 == LOW);
{
Serial.println(“LOW”);
}

}
}
}

buttonPushCounter = 1; //reset
Serial.println(“Reset”);
}
else {
// turn LEDs off:
digitalWrite(ledPin2, LOW);
digitalWrite(ledPin3, LOW);
digitalWrite(ledPin4, LOW);
digitalWrite(ledPin5, LOW);
digitalWrite(ledPin6, LOW);
digitalWrite(ledPin7, LOW);
digitalWrite(ledPin8, LOW);
digitalWrite(ledPin9, LOW);
digitalWrite(ledPin, LOW);
}
}

1) Traxxas Nitro Monster Truck

2) HPI RS4 Rally Car on Brushless Lipo Setup

3) Kyosho Custom Stadium Truck

4) Tamiya DF03 RA with Stock Motor

The Traxxas Monster Truck has all the power in the world – but a high center of gravity requires the truck to go around tight corners relatively slowly.

The HPI RS4 Rally shocked everyone by matching the acceleration and almost outrunning the Traxxas during a tarmac drag race. But lots of power can be tempting and all to often it proves too much of a temptation for the driver.

The Kyosho Stadium truck was a custom vehicle build by its owner from many spare parts. The from axles failed early in the race.

The Tamiya Subaru was the car with the best handling. Drag racing was no fun, but on the tight Rally track the car really was in its element and won the race.

Bottom Line: POWER IS NOTHING WITHOUT CONTROL

I identified 4 major needs:

1) Easy to activate – but waterproof On-Off Switch

2) Totally sealed Body and Chassis that does not let any dirt in

3) Easy access to Charging Port/Plug for Batteries

4) Bigger Bumper to prevent Wheel and Suspension damage

The best solution was to integrate those with my Mud and Dirt Electronics Cover based on the Tamiya Dark Impact Body

And here is the RC car in its parking lot and charging bay in the shed. This reduced the setup time to run the car from 10 minutes to under 2 minutes.

Yes we are taking about driving our precious RC Car in the mud, rain and through big puddles of water. We don’t have snow where I live but I would love to do that too (Sweden Rally anyone).

The big problem is that the tub of the rc car will fill up with a bunch of dirt and water in no time at all. On my backyard track I have to dump out the car after 5 laps because it is filled up with dirt. I initially tried building my own electronics dirt and splash cover but results where less than stellar. The big question you may ask is why not use the Tamiya “Dark Impact” body as cover. Well A) I did not know about it initially – although a quick google search would have revealed it and B) once I did find out I was simply to cheap to blow $35 bugs on a piece of plastic. Needless to say I finally got over myself and ordered one on Ebay.

I read a bunch reviews regarding the Dark Impact Buggy and quickly learned that the number one complained was that the car fills up with dirt – which told me I can’t just cut along the lines that Tamiya suggest to trim the body to fit. I carefully cut away one plastic piece at a time to make sure I cover more open spaces compared to Tamiya suggestions.

Picture below: Test driving the Dust and Dirt Cover based on the Dark Impact body:

One concern is of course heat. Having a tight fitting body is awesome  – but that also means that there is zero airflow inside the body. People with high performance brushless setups will run into trouble here. Thank goodness I flooded mu Brushless setup and only have the stock 520 motor and electronic speed controller (ESC). Which means heat is no problem when I let my car cool down every 5 laps. 5 laps turns out to be a good number to run on my track just feels right to do five laps then pause look at lap times and go again. A bit like Rallycross events if you will.

Anyway, so the reviews talk about dirt getting still in, which meant I have to do a bit extra trickery to keep my car “clean” on the inside. One thing I did was fill the sidepods with styrofoam – this will prevent any water that makes it in from getting trapped. The white styrofoam is also good fro quick inspection through the window of the car – cause it is white.

No most expensive part in my receiver – so I really wanted to get it out of harms way. I ended up mounting it to the roof of the Dark Impact body inside its very own plastic cover. By the way the plastic covering the ESC comes from a jewelery box from HotTopics (thank god for girl friends and wifes). One concern was that the cables are getting destroyed by the exposed driveshaft. What I did is simply mount a piece of plastic and screwed it into the original antenna mount.

The body itself is screwed onto the tub. I know that a lot of people use Velcro  – which I am sure works fine. But I liked the idea of nuts and bolts seemed cleaner, stronger and easier in the long run. By the way the nuts are held on the inside with hotglue in position.

Here is a picture showing the styrofoam, ESC mount and cover as well as driveshaft prtection:

Turns out it is a lot of fun to drive the Tamiya Df03RA chassis with just the Dark Impact cover. Less weight and a lower center of gravity make for fun and exiting driving. However nothing beats the look and size of the Subaru Cover on top of it. So I guess it is performance versus looks. Just like in the real world. I will post lap times comparing the Dark Impact with rear Wing, without rear Wing and of course with the Subaru body.

Here is how the Dark Impact body looks inside the Subaru body. I was surprised just how small it is.

(too bad I misspelled Tamiya…)

The following article will compare the Tamiya Subaru 1/10 scale model versus the real Subaru Works Team entry. The scale model is really close in scale. Well done Tamiya.

All measurements are in metric – we are talking engineering here. The data comes from a variety of sources. Please leave a comment if you have more correct numbers.

Cost:

Subaru Impreza WRC 2007 | Works Team entry build by Prodrive/UK :  Est. $750,000

TAMIYA DF-03 RA Subaru Impreza WRC 07 : MSRP $332

Cost in Scale: $332 x 10 =  $3320

Model to Real Car Difference: – $746,680

Length:

Subaru WRC: 4465 mm

Tamiya: 445 mm

Model in Scale: 4450 mm

Model to Real Car Difference: -15 mm

Width:

Subaru WRC: 1800 mm

Tamiya: 184 mm

Model in Scale: 1840 mm

Model to Real Car Difference: -40 mm

Height:

Subaru WRC: 1390 mm

Tamiya: 193 mm

Model in Scale: 1390 mm

Model to Real Car Difference: +/- 0 mm

Wheelbase:

Subaru WRC: 2535 mm

Tamiya: 266 mm

Model in Scale: 2667 mm

Model to Real Car Difference: + 132 mm

Wheels (Rims) for Gravel :

Subaru WRC: 15 inch (Tarmac Wheels: 18inch)

Tamiya: 1.96 inch

Model in Scale: 19.6 inch

Model to Real Car Difference: + 4.6 inch Gravel (1.6 inch Tarmac)

Tires for Gravel :

Subaru WRC: 225/60

Tamiya: 31/8

Model in Scale: 310/80

Model to Real Car Difference: + 85/20

Weight:

Subaru WRC: 1230 kg

Tamiya: 1.8 kg

Model in Scale: 180 kg

Model to Real Car Difference: – 1212 kg

Engine Kwh :

Subaru WRC: 224 Kwh

Tamiya: o.5 (stock 540 Mabushi Motor @ stall)

Model in Scale: 5 Kwh

Model to Real Car Difference: -219 Kwh

Engine Bhp :

Subaru WRC: 300 bhp

Tamiya: 0.65 bhp  (stock 540 Mabushi Motor @ stall)

Model in Scale: 6.5 bhp

Model to Real Car Difference: -293.5 bhp

Power to Weight Ratio (kg to bhp) :

Subaru WRC: 4.1 kg/bhp

Tamiya: 2.76 kg/bhp   (stock 540 Mabushi Motor @ stall)

Model to Real Car Difference: + 1.43 kg/bhp

0-100km/h | 0-60mph :

Subaru WRC: 4.8sec

Tamiya: ____

Model to Real Car Difference: ____

In its first year my Subaru DF03-RA which runs on all stock parts with a descent battery (except for a brushless motor for the first 3 month until I submerged the motorcontroller) completed about 2250 Laps around the track. That makes for about 80 laps per session and a total of 28 Sessions in a year. Amazingly at a track length of about 50 meters (150 feet) that adds up to 112.5 km (70 miles).

The track has undergone some small layout changes and one extension. The most recent addition brings the total length to 205 feet / 62.5 meter.

The car chassis is in amazingly good shape but the body needed a little fiberglassing in the front area. Tire wear is minimal due to the soft clay surface of the track.

My homemade mud/water and dirt cover did not work as well -hence I finally ordered the “real thing” which is the body for a Tamiya Dark Impact.

Race lap counter and timing is still an issue. Also the webcam based lap timer works fine, I don’t like the fact that I need to set up a PC outside. I takes way to long. I did buy an Arduino microcontroler and LCD screen which I will build into a Waterproof Infrared triggered timer setup. More on this after Christmas when I have time to build it.

Here is a satellite view of the new track layout with the addition.

Anyway, we are back in Maui Hawaii from vacation and while doing some yard work (digging up cane-grass) I came across an old concrete patch in the yard. As Rally fan you are probably thinking the same that I was thinking – BRILLIANT now I can have my track be a mixed surface environment -just how it is supposed to be for Rallycross and Rally cars.

The real problem is to get the soil leading to the concrete patch to become hard enough to drive on it. The original track took about 2-3 month to harden and compact. I don’t have any tools or tractor that could help. I thought about driving the family car over the track, but it won’t work due to my wifes potato patch close by. And trust me you don’t mess with a wifes garden -ever!

The extension will add an additional 90 feet / 30 meters to the track. This will bring the track to a total of 220 feet / 67 meter

Looking at it in a 1/10 scale:  I am still short by almost 130 feet / 40 meters to have a “true” 1/10 Rallycross track which are usually 0.932 Miles  //  1.500 km long.

Here is a picture of the new section under construction.