ESP32-CAM building your own robot car with live video streaming – Design of the chassis

The chassis can be built from many materials or packaging that would otherwise end up in the waste. So I have made good experiences with chassis that are built up individually from cardboard. However, here the work with scissors and carpet knife is necessary and therefore it can perhaps come to injuries with children. Also the construction of a chassis purely from cardboard is a little more complex but more creative than a finished box made of e.g. plastic like an ice cream package. In the following I describe the building of a chassis out of an ice cream box because there are no sharp knives needed to cut the chassis. Further advantages of an ice cream box are, that it is cheap to have, stable, from waste something else is made and big enough to accommodate all components of the robot car. Also the thin plastic of the box is easy to work with and in case of errors it can be replaced cheaply.

The following picture shows the chassis of the robot car built from an ice cream box.

ESP32-CAM robot chassis

Table of Contents

Mounting motors

The two motors are screwed to the left and right on the outside of the ice cream package with M3 screws. It is important that the connecting cables of the motors point into the inside of the packaging, i.e. do not touch the outside of the chassis. Also these small yellow model motors have a small knob on one side which sticks out a little bit. For this small knob you also have to drill a hole per side into the side wall of the chassis. The small knob gives the motors additional stability when they are mounted.

Ideally, the motors should be fixed to the chassis in such a way that they are as far forward as possible in the back of the chassis, i.e. to just before the rounding of the plastic box.

ESP8266 NodeMCU robot car dc motor mount

The motors themselves are then attached to the housing with two M3 threaded screws with a length of approx. 3cm each. These screws should be available in every large hardware store.

ESP8266 NodeMCU robot car dc motor screws

Before the holes are cut or drilled into the chassis or the ice pack, they must be measured exactly. Otherwise it will not be possible to fix the motors correctly. It is ideal if a small drilling template made of paper is made before drilling the holes. With this template you can check the correct fit of the holes and the marks for the three holes per motor can easily be transferred to the chassis.

After drilling the holes in the chassis with a 3.5mm drill for the fixing screws and for this small knob with a 3.0mm drill, the motors should be fixed to the chassis as shown below. Before the motors are screwed on, the cables must be soldered to each motor.

Solder the cables to the motors

To do this, it is best to remove the fastening loop with which the motors are fastened in the yellow gearbox. After removing the fastening loop, the motor can easily be pulled out of the housing. So you don’t damage the plastic of the gearbox with a hot soldering iron.

After the cables are soldered on, the motors are put back into the gearbox and fixed with the fixing loop. Afterwards the motors are fixed to the chassis.

The following picture shows the finished result.

ESP8266 NodeMCU robot car dc motor mount final

Note: The following pictures show an ultrasonic sensor. This sensor was developed in a project where an ESP8266 NodeMCU was used as a computing unit. Possibly the HC-SR04 ultrasonic sensor is still used in this project with the ESP32-CAM.

Mounting ESP32-CAM with camera

Ideally, the camera or ESP32-CAM is mounted on the front of the chassis, ideally exactly in the middle. There are now two ways to mount the module.

On the chassis itself:

With this module and chassis it is possible to drill a hole in the housing through which the camera of the ESP32-CAM module can be inserted. When mounting the camera, however, make sure that it can be easily removed from the housing. If you want to take the component carrier with the individual components out of the robot car, the camera should not be firmly attached to the housing. In this case the removal is rather difficult because all cables have to be disconnected or are no longer possible.

On the component carrier directly:

I decided to use the solution of attaching the ESP32-CAM module to the component carrier. So I can easily take it out of the housing without the risk of damaging the flat cable of the camera or having to disconnect many cables.

ESP32-CAM chassis mount

Attaching electronic components

The remaining electronic components are attached to a piece of cardboard, the so-called component carrier. This component carrier rests on the two motors and fits exactly into the interior of the chassis. At the back of the chassis you might have to glue a piece of cardboard to the chassis which supports the component carrier at a 3rd point. This cardboard has the height of the electric motors. This way the component carrier does not tilt or bounce in the chassis but rests securely on three points.

Now all electronic components can be fixed on the component carrier. These components are the motor driver, the servo controller and the I2C hub.

Now the electronics carrier in the chassis looks like this.

ESP32-CAM robot electronic components

Summary

The construction of the chassis is now done with a lot of creativity and hopefully with joy of tinkering and all components have found their place in the chassis. Certainly drilling the holes for the mounting of the motors and maybe for the ultrasonic sensor was the more complex part in this section. But the fixing of the electronic components on the cardboard should have been easier again.