By: Ahmed Abanumai (Manufacturing Engineer)
As a result of the new design, a new issue arose when we needed something to mount the servo for the mirror we were using for our vision system. For that, I designed a mirror base that would allow us to control the mirror via the servo. This would allow us to have some control over the received image. It must be noted that our visions system will only have a panning capability as specified by our requirements (unlike Mini RoSco’s pan and tilt vision system).
Mirror Base Objectives:
1. The base must carry the mirror
2. The mirror angle over the base should be adjusted to give a clear reflection of the outside.
3. Easy to be controlled via the servo.
The hole in the middle is where the servo is attached to and allowed to rotate. The angle at which it is tilted is 50° in order to capture an image that can reflect directly into the camera of the Samsung Galaxy S2, allowing us the ability to control the picture we are receiving.
Wheels and Tracks
Our Micro Rover is supposed to be small enough that we can put small motors to run it. We did not want motors that had a high torque. Through our speed trade-off study, we concluded that the bigger the wheels were, the less work was needed to run the rover.
1. As large as possible (without ruining the integrity of our required base dimensions).
2. Total of six wheels.
3. The wheels’ teeth should have reasonable gaps to maintain the tracks.
4. Easy to assemble.
With a total of 18 teeth per wheel, our tracks had to be design accordingly. The thickness is 0.45 inches with a nut hole shaped to assemble the wheels and mount them to the motors and/or chassis.
The track diameter is 5.10 inches with 52 holes designed to hold the teeth of all 6 wheels (3 on each side). The thickness was designed to be less than the wheels with 0.4 inches. I decided to make use of Ecoflex PLA filament to make them. The biggest benefit of Excoflex PLA is that it stretches easily, allowing us to attach the tracks to the wheels without much difficulty.