Ever since I was a little kid I was fascinated by night races. Regardless of what form of racing – night time racing has something very special to it.
Unforgettable moments of night racing are Rally Cars in the snow during the Sweden Rally, glowing brake discs and the super bright pitlane in backdrop to the dark Circuit de la Sarthe better known as the 24 hours of Le Mans.
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.