Here's what you'll need for this project:
-2 thin wooden disks
(I literally was walking to work and a construction worker was throwing these perfect wooden disks out. They were very thin and light. Some type of balsa wood maybe. You could probably cut them out of thin plywood or heavy cardstock)
-2 cheap remote control cars
(If you have 1 or 2 of these laying around then you're set! Other wise pick up a few at K-mart or a garage sale. All you need it the forwards and reverse motor.)
-Some scrap wood
(We used what we had laying around: 15 inch. length of 1"x3", 7 inch. length 2"x4" and a plywood base roughly a 1 ft. square.)
-Insulated copper wire
(Just your standard wire we had laying around the shop.)
-Misc. mounting hardware
(Really a hodge-podge of screws, washers, nuts and bolts we had laying around. The one thing we bought was 8 "tapered faucet washers." They are big rubber washers that help secure the R/C car wheels to the wood disks.)
(You can pick this babies up at Radio Shack and use them like dimmer switches for the R/C motors.)
For the complete video, watch below!
Step 1: Prepping the Cars
As I mentioned before all we are using is the back wheels that control forward and reverse. So we can remove everything but the rear motor and wheels, circuitry and battery pack. This means you can get rid of the car body, front wheels and motors and anything else that is getting in your way. I basically removed the top piece that makes it look like a car. Disconnected the wires going to the front motor. Then remove the front motor and wheels. Lastly I took my rotary tool and cut away any excess plastic from the remaining frame. Leaving a nice and neat, ready to mount, package consisting of the rear wheels, motor and gearbox, the circuitry and battery pack. All attached to the rear half of the frame. Repeat this on the second car (Car B) but detach the gearbox and wheel assembly if you can. The only thing that should connect this to the rest of the car is the 2 wires going to the circuitry from the motor. Our second car had the wheel assembly in a handy little box that popped right out of the frame.
Step 2: Wiring in Your Rheostats
This is a really easy job, but you will need to solder a bit. Make sure you are really careful and if you've never soldered before here is a cool tutorial. Start with "Car A". What you're looking for is the 2 wires that come from the circuitry to the motor. You'll want to wire in the rheostat inline according to this fancy diagram I drew below. Finish up with some electrical tape around your solder points then mount your rheostat somewhere on the car frame with more tape. Repeat this process on Car B, which should have the gearbox, motor and wheel assembly detached from the rest of the body. The only difference is you'll want to add a few feet of wire so that the motor and wheel assembly can be mounted away from the circuitry.
Step 3: Prepping the Wooden Disks
You'll want to figure out the center of these disks to help balance everything. The way I did this was to balance the disks on the tip of my knife starting from the "center". If the disk tipped to one side I would move the knife and try again. This helped me find where the center of the disk was in terms of weight. Which ended up being different then the center spatially. Once you figure it out mark it with a pen.
Step 4: Putting Everything Together
Take Car A and mount it to the end of a 2"x4". You should be able to use
some wood screws and go right through the plastic to the 2"x4". Make sure it's firmly attached and you still have access to the batteries and on/off switch. Next mount the 2"x4" to the plywood base with "L" brackets. Now we can attach the first wooden disk to the tire of Car A. You already know where the center is so just use some bolts, nuts and faucet washers to mount one of the disks to one of the cars rims.
Next mount the wheel and motor assembly of Car B to one end of the 1"x3". Then mount the other end of the 1"x3" to the wooden disk that is mounted to Car A. Take care to try and balance this.
Now you can mount the second wooden disk to Car B's wheels and motor. Use the extra length of wire and attach the circuitry and battery pack of Car B to the base. We used Velcro. Finish up with the paint job of your choice.
Step 5: Mounting the Camera
This is the easiest part. Use some gaffers tape and secure the camera to the wheel of Car B that isn't attached to the wooden disk. We tested the rig with my small point and shot digital camera, but ended up using a small miniDV cam for the test film. Both cameras would work fine, but keep in mind different cameras will effect the balance of this rig.
Step 6: Mounting the Rig
The cool thing about this rig is that it works standing on a table or upside down mounted to the ceiling. If you are going to mount it somewhere high I would recommend doing so on a wooden structure you do not care about. You don't want this mounted in plaster or stucco because it could fall out and break the rig and camera. The rafters in your garage should work great. It doesn't really matter that you put a few holes in rafters and you'll get a nice secure mount. Take everything off the base so you can be free to mount just that. Then re-attach everything else once that is in place. There are probably better and less invasive means of mounting this rig and if you think of any I encourage you to let me know!
Step 7: The Conclusion
This rig was probably the most challenging thing I've built for the show. As much as I'm proud of it, the rig could use a lot of improvement and has some weaknesses. It's not very sturdy and can be a bit wobbly at times. Also it is really confusing and touchy to operate. You should really take the time to practice on it or have 2 people operate it for the shoot. Don't forget it has 2 separate remotes. If you have any questions or comments please leave them below!