How To Build a 2WD Robot
There are many ways to do build a 2WD chassis. We will provide some guidance below to help you build what we consider a simple 2WD Robot that is not a POS. There are cheaper ways like directly coupling the wheels to the motors, but this method puts a lot of strain on the motors and, in our opinion, is not a good practice unless you are using heavy duty motors like our wheel chair motors or if you are planning on a making a really light weight and light duty robot. The issue with supporting the axles with bearings is you end up with a pretty wide robot once you have the bearings and the motors all lined up together.
If you have never built a robot before, a simple 2WD platform is probably the best one to try. It still requires some basic mechanical and electrical skills though. If you don't want to design your own 2WD robot, we offer a 2WD platform kit that has all of the necessary parts. In this kit we use our tube frame motor mounts to mount the motors, a ball bearing, and the wheel axles. This provides a very strong platform while keeping the width of the robot reasonable. We also offer a heavier duty 2WD robot that uses IG42 motors and can support very heavy weights while still being able to turn with ease. This robot has a welded chassis and bearings in the wheels, which are chain driven.
Below is a discussion on how you can build a robot using parts from our site.
Making a Rolling Chassis
You can use two of these.
You can use 6 inch wheels with these motors (1 set of wheels and 2 motors needed)
Or you can go with 10 inch wheels with these motors (1 set of wheels and 2 motors needed)
Depending how much of a load you are carrying around will depend on the size of the motors you will need. The above combinations will give you plenty of power and carrying capacity over most terrains. To calculate the speed check out speed calculator.
Using the above method is a direct drive method. The Motor Mounts provide a bearing hold location for the included bearing on the axle and wheel sets, so the load of the robot is not entirely loaded onto the gear motor shaft. The disadvantage of this method is that everything is in-line, so the robot ends up being kinda wide. The other choice is to stagger the motors and use chain drive to the axles. The axles will then need to be supported with dual bearings. This method is a lot stronger since the motor does not have to support the robot's weight at all, just turn the shaft. The disadvantage of doing chain drive is the extra complication and cost.
If going the chain drive route, then you will need either one of the below axles:
You will also need bearings and sprockets. Be sure to see our discussion of chains, etc too.
You would mount the motor mounts, axles and wheels on a plate for a chassis. A simple piece of wood would be fine. Get some casters from any hardware store. You now have a rolling 2WD chassis.
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Power for your 2WD Robot
The simplest and cheapest way to get power to the robot is using Seal Lead Acid (SLA) Batteries. They are heavy batteries, but since this is 2WD, turning via skid steering is a lot easier than a 4WD robot. Hence weight is typically not a issue with the design.
For wiring and sizing the batteries look at our robot wiring page.
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Wiring the Motors
For wiring the motors look at our motor wiring page.
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Adding control to the Robot
The next thing is controlling the motors. The simplest way is with via RC control with a motor controller that takes RC input.
The best value for the money is this combination. It will get you RC control and its easy to hookup:
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