Reading Week! Milestones achieved, and planning ahead

Many milestones were hit this week for our team. On Tuesday, we started the beginning of the long integration process, testing out how Tom's coded pulse width modulation would work through Mason's driver board when connected to the fully mounted (and functional) motors. The results were very promising.

 

On the electromechanical side specifically, The final structure of the robot is complete. The motors were remounted using steel strapping instead of plumbing fittings, which allows them to be both well secured and easily adjusted. I finished tweaking the arm system today, and will upload a video to show how it works. 

http://youtu.be/tY5pXn05KZw

Basically, as there will only be one pole per course, there was no need to actuate the arm. We designed our arm so that it would be able to just plow right into the pole and bounce back into place when past it. This is possible without a lot of torque on the robot because we implemented a rotational arm using a standard bearing. Because we chose to build the arm out of balsa wood, it is also extremely light, and does not affect the balance or weight distribution of the robot in any way. We also discovered today that even if we are completely off course and the arm comes into contact with the buckets, it is light enough that it does not displace, damage, or mark them in any way, making it harder to be disqualified in competition.

 

I also spent some quality time with the rotary tool - they are very useful and fun to use. I used it to cut circuit boards to specific sizes in order to facilitate the creation of sensors that will have to be mounted to the robot. 

 

Earlier in the week, two encoders were mounted onto the base. This was done above the current dual drive system in order to preserve our relatively thin width (20cm). Using the same gear ratio as what is attached to the wheel's axles, the encoders will read the exact output of each motor directly, allowing us to determine the speed of each driven wheel individually and allow for more precise control of the robot. 

And a zoomed in picture of the mounting crossbar 

 

Here is a picture of the robot fully built - the battery needs to be mounted as well as the rest of the circuitry, but the frame itself is complete. I also need to secure the white gears to the motor shaft completely in order to reduce slipping and inefficiencies - when I go home to St. Catharines during reading week I'll definitely be hitting up the Canadian Tire. I also need to look into securing the balsa wood arm pieces more securely - I was thinking either small clamps or carbon/plexiglass strips (as recommended by a few TA's - these are used in airplane models). 

Now, to study for ECE and MSE.

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