Have you ever wanted to drive around in a tank? Well this might be the next best thing. With not a lot of skill required, anyone can build this tank chassis. Then all you have to do is customize it for your use, be that recreational or dictatorial (though the last one might void your warranty) I'll be honest, I didn't come up with this on my own, so Here is the original. Have fun!
Step 1: In the Begining
Bill of Materials
- Cheap RC car (I used: Super Fast Fireball Drift R/C Sports Car Remote Control Drifting Race Car 1:24 + Headlights, Backlights, Side Lights + 2 Sets of Tires)
- Tamiya 70108 Tracked Vehicle Chassis
- Tamiya 70168 Double Gearbox L/R Independent 4-Speed
- Battery (will differ)
- Scrap paper
- Wire Cutters
- Small Screwdrivers
- Exact-o Knife
Step 2: Gearbox
Assemble the Tamiya 70168 Double Gearbox, paying close attention to the gear order and orientation. I wanted to use the Type D ratio of 344.2:1, but an error in my method changed that, so feel free to use whatever you want. You probably won't have problem with power, as I wound up using a low gear ratio, and it is still plenty fast. BE VERY CAREFUL when assembling the gearbox, if you lose anything, you're stuck. Not a lot to say here, except I recommend doing one half, carefully screwing one screw in, and then doing the other half. Be patient, you will get it eventually.
Step 3: Attaching Motor to Chassie
Next, position the gearbox on the chassis, making sure the mounting holes are lined up. If you are using a gearbox with a forward axle, line up the mounting holes on the gearbox with the rear mounting holes on the chassis. The gearbox mounting holes, by the way, are the ones closer together. If you use a gearbox configuration with a rear axle, line it up using the forward holes. Mark the center of the holes with a pencil, and drill them the same size as the other holes. I used a drill press, but it could be done with a steady hand and a hand drill. You might want to drill them at a slight inward angle, as the double gearbox is really wide. If you drill the wrong holes, the tracks will be loose, which is what happened to me. If this happens, you can either re-build the gearbox with the opposite axle position, or drill new holes.
Step 4: Wheels and Tracks
Go ahead and screw the mounting hardware on. For this, you can use the instructions included with the tracked vehicle chassis. I recommend mounting the brackets to the top first, then the ones on the bottom. You will need four axles. Be sure not to use the one with sides, it will only mount the driver wheels, and won't turn as well. Cut out six road wheels, the two sprocket wheels, and two follower wheels. I used the big ones, I don't know how to do it otherwise. You will also need one axle cap for each wheel, excluding the two sprockets. Attach a road wheel and a cap to one end of an axle, and repeat until you have used half of your wheels. Thread one end of the axle through one of the holes, add the other wheel, and cap it off. Repeat for the rest of the wheel-axle assembles. Cut out the track pieces you need as specified by the instructions. If you can't connect them, look for a YouTube video, I don't know how to demonstrate it with words and pictures.
Step 5: Total Control
This step is mostly up to you, as I don't know what RC car you have. In general, the screws are going to be on the bottom. You want to remove the top decorative piece. Once you have the top off, unscrew the antenna and the circuit board, if needed. You need to pay attention to three groups of wires plus one, the two for the motors, the battery box, and the one to the antenna. The rest you should be able to cut off or unplug. I recommend cutting the wires as long as possible, and in groups. When you have cut a set of two, tape them together with a little label. I used scrap paper. When everything is cut free, put together the battery box for the Tracked Vehicle Chassis, the directions should be fine. (Note: I didn't use the switch, as one came with the RC car, but if yours doesn't you can use the switch.) Pick a forward direction, and face it away from you. Hold the remote in hand, and look at the left stick, (the drive stick). You could try and start with the other, but it's usually steering, and that one's weird. Connect the drive motor wires to the left (probably) motor. Unfortunately, I can't tell you which wire to connect where, as it will differ with the number of gears you use, and my wires were blue and black (really?). I recommend taking off the small piece that slides on to the motors, it makes it easier to slide them out. Also, you probably want to do one motor at a time and test it when you're done.
Step 6: Finishing Up
Screw down the battery box with the screws provided (the little ones). I used one, but feel free to use both. I taped the antenna to the gearbox. You find the best place for your applications. And finally, I attached the circuit board to the chassis with a piece of cardboard with a hole cut in it. Once you have that down, you should be all done. Test it, and if it doesn't work try below:
Doesn't drive at all: Is it on? Check for loose wires.
One (or both) of the motors drives in reverse: Switch the wires
It explodes: Sorry, try the FBI, I think someone might be out to get you =(
If I missed something, put it below in the comments.