Mounting Wheels to Robots
One of the most daunting tasks for a beginning robot builder is mounting motors and wheels to their robots to make them go. Learn the basics of robot motor and wheel mechanics here.
Motors and Mounting Brackets
The motor for most robots should have a built-in gear head. A good speed of a motor for most robots is about 200rpm.
There are many different sizes, speeds and shaft sizes for DC motors, so I will only write about one type of motor as an example for this article. This motor is a 200rpm gear motor that has mounting holes in it for using an angle bracket to mount to your robot chassis.
You will also need some angle brackets to attach the motor and wheels to your robot chassis.
Here's where you can get the 200RMP Gear Motor, Connecting Wire, and Mounts.
Wheels and Hubs
DC Motors have various shaft sizes. The common shaft sizes are 3mm, 4mm, 6mm, 12mm, 1/2in and 3/8in. You will need something to couple the shaft of the motor to the wheels. For this, you can use universal hubs that have mounting holes to attach the wheels to and a set screw to mount the hub onto the motor shaft. Another option is to purchase wheels that are matched with a hub such as the wheels I will describe in this article.
Some considerations for wheels are the height, width and materials they are made from. You can purchase rubber R/C truck wheels that 12mm hex hubs are made for, or you can purchase a set of wheels and hubs that are made for each other and that will fit onto the motor shaft of the 200rpm DC Gear Motor mentioned in this article.
The drive system for an autonomous mobile robot is a differential drive system. This is a chassis with two drive wheels that independently move forward and backward with a balancing caster in a triangular configuration.
This will allow your robot to maneuver very nicely in most any terrain (there is always a caveat in robot building that you have to have a trade-off in maneuverability and that no particular drive system is perfect for every situation).
Here's where you can get the Wheels, Hubs, and Casters.
