Project:

The Ultimate Remote Control Car II (Even Better)

Designer(s):

Jeff N8QPJ

Description:

I learned a lot building the first Ultimate Remote Control Car and used that experience to make many improvements in the design and building of The Ultimate Remote Control Car II.

The most obvious improvement was stuffing all the electronics inside the Hummer body. This took a great deal of effort. The items under the body include three battery packs, two servos, an RC receiver, an HT, an electronic speed control, drive motor, 2 inch speaker, video overlay board, mic preamp, LED flasher board, and power distribution board. Other improvements include 2.4Ghz FM ATV for the video and audio transmission, Cylindrical B&W camera, better camera pan and tilt assembly, 50Mhz RC radio system, more sensitive microphone, flashing LED’s, and separate switches for the different systems.

Getting the car up and running is easy. First turn on the RC transmitter. Then turn on the RC receiver on the car. Turn on the main power switch that feeds power to the systems switches. The system switches are labeled 2.4Ghz/Cam, 440 HT, IR LED’s and Flash LED’s. Turn on the system switches and check the video monitor for a picture and audio. Key the HT on your belt and listen for audio coming from the 2-inch speaker in the car. Move the controls on the RC Transmitter and check for correct response. That’s it, now you’re ready to have fun!

Some Technical Information:

The RC vehicle used for this project is a Tamiya 1/12 scale M1025 Hummer with an electric motor. The Hummer came as a four-wheel drive but I made it a rear wheel drive only so I had more room for stuff. A Novak 610-HRV electronic speed control with reverse is used to control the car motor. The RC radio is a Futaba T6XH FM six channel helicopter unit. The RC receiver is a seven-channel FM unit. The six channels are split up as follows. Steering, electronic speed control, camera pan & tilt and two spares for future goodies. The camera is a high res. black and white cylindrical (2" X .9") water-resistant unit from ATV Research. The 60-degree tilt mechanism consists of the above camera attached to a micro servo. A gear glued to a servo that drives another gear from an old VCR achieves 220-degree panning. The ATV transmitter is a modified 2.4 Ghz Wavecom Jr which outputs out about one mw. The antenna used on the transmitter is a half wave sleeve dipole rubber duck from Mobile Mark. The ATV receiver is a modified 2.4Ghz Wavecom Jr. which can accept external antennas. The infrared illumination is provided by ten high output infrared LED’s (BG Micro) on a circuit board which is attached to the back of the camera so I can see in the dark. Having the Infrared LED’s on the camera allows the light to shine where the camera is looking. The audio from the car is provided by a small microphone mounted in the front grill and amplified by a preamp circuit mounted to the under side of the hood then feed to the 2.4 Ghz ATV transmitter. To transmit audio to the car I use a headset attached to a HT on my belt. A switch on the Futaba RC transmitter keys the HT on my belt by way of the trainer cord jack on the RC transmitter. To receive the signal from the HT there is a 440 Mhz Kenwood mini HT mounted in the Hummer. Attached to the Kenwood HT is a 2-inch speaker, which gives a good audio level so I can talk to people through the car. Two super bright red LED’s spaced two inches apart mounted in the front grill alternately flash for a good visual affect. The power for the car is provided by three battery packs. A 4.8V four-cell AA pack powers the RC receiver and the servos. The drive motor is powered by a 7.2V six-cell C pack. All the other stuff is powered by a 12V ten-cell sub C pack. All the above batteries are nicads. My call sign is overlaid over the video with an Intuitive Circuits OSD-SA video overlay board and there are large white letters pasted to the roof of the Hummer in front of the camera.

Hardware:

Hardware Sources:

Conclusion:

Driving the car by watching the TV screen is very easy because the driver’s perspective stays the same whether the car is coming toward you or driving away from you. Navigating the car through obstacles, approaching people and talking to them through the car and the ability to drive around in complete darkness are just a few of the many things that can be done with The Ultimate Remote Control Car II. The car is a big hit at club demos. After seeing the car in action people will remember the Ultimate Remote Control Car II (Even Better).

- Jeff Basting N8QPJ

Fig 1.0 - "The ultimate ATV car II"

Fig 2.0 - "The profile"

Fig 3.0 - "Pan/tilt camera with infrared LED's"

Fig 4.0 - "2.4 GHz transmitter and system switches"

Fig 5.0 - "Gulp..."

Fig 6.0 - "Notice the glare of the infrared LED's on my glasses"