How to Build Gas-Powered RC Cars
Radio controlled (RC) cars can either be powered by a gas engine or operated using electricity 1. Cars that use a gas engine are preferred by hobbyists seeking longer driving times. This is because battery powered cars must be recharged. Excursions with gas powered RC cars last as long as the fuel supply and typically the cars can achieve greater speeds 1. Many ready-to-ride (RTR) and assembly kits come equipped with gas engines, but many purists like to make their cars from scratch using a sketch or blueprint.
Draw a sketch or rough diagram of the car's body design or decide if you want to buy a kit. Kits include all the parts you would need to purchase separately but are typically a bit more expensive. They also include a diagram of how the parts should fit together. If you want to draw your own diagram, check out existing ones in books like "The R/C Car Bible" or search the forums at RC hobbyist websites like CNCZone. The steps below will also provide a general idea of how parts work together. Sketches should be drawn at one-eighth scale from several angles and measured from the wheel.
Purchase the parts you will need. The type of surface you will be driving on and the quality of parts you want to use will help determine what kit you purchase. Build-it-yourself kits generally use higher quality parts that are more durable on rough roads. It may also prove beneficial for the hobbyists to be more intimately involved with the actual assembly as this will provide good background knowledge for when he needs to make repairs in the future. RTR kits are less expensive and may still require some assembly. Make sure the kit you buy is gas powered, because some are not. Whether you go with a kit or draw the design from scratch, you will need a body for the car or a metal plate to cut into a body; the engine with two attached wires and two-way communication abilities; the servomechanism; oil-filled shocks; front and back axles; resisters, steel rod and caps and an electrode; wheels; a remote casing with a trigger mechanism and two antennas. These should be included in most car kits but ask to compare this list to a parts list.
Use shears to cut the metal plate into a chassis shape according to your sketch.
Place the engine near the front center of the chassis, pulling back the wires for the time being. Screw the two shocks onto the chassis, one on each side of the engine.
Attach the wheels to the shocks, making sure they are all facing the same direction. Spin them around to ensure they are adequately mobile.
Situate one axle in the front and another in the back. The axles are for steering the car in various directions.
Take one of the motor’s wires and attach it to the bottom right copper ring of the front axle, then connect the second wire to the second axle’s gear assembly on its bottom right corner. Make sure the wires are taut around the axles and clip them for length if necessary.
Install the servomechanism at the same level as the motor.
Drill a hole in the remote casing and put the electrode and resistors inside the base. Take the trigger wire and connect it to the resistors. Slide a steel rod through the hole and screw knobs on both sides, then snap the remote shut.
Secure one antenna on the car and the other on the remote top.