Class #5 – Building Part 1 – 16th of July
I ran into a few challenges in creating my prototype. The biggest problem being the Laser Cutter not working in the labs. I wanted to have the chance to run multiple trials on my robotic arm design, but because my only solution was to place an order off-campus for laser cutting and how expensive their fee was (also their long turn around time), I was limited to only laser cutting once.
Now putting that aside, I needed to make sure my design was complete before I sent it to be laser cut. There are a few things that I needed to be done:
- I needed the structure to be strong. The arm should be able to handle the weight of the 3D doodler pen and not just that, but also the servo move with a lot of force, and the arm should be able to handle sharp and hard movements.
- I needed reliable connections between the robot arm segments. The segments are connected on one side through the servos. But to make it more stable, I decided to make small circular joint on the other side of the segments to reduce the chances of the segments separating from each other.
- I need the arm to be easily opened to replace components or gain access to the 3D doodler pen to change filament or to service it. I decided to use screws to fix one of the sides; in that way, I can have access to any part of the arm and anytime. This is something I have learnt from my previous projects. You assemble all the pieces and glue them in their place and only then you realize that one of your components is not working and there is no way for you to fix it other than un-glue everything (if that is even possible).
- The dimension of the arm was another big challenge. To get an excellent working area under the arm, I decided to adjust the angle of the connection to the table. In this way, I get a smaller footprint for the robot and gain access to a more significant working area. The limitation is that each of the joint can only reach +/-90 degree. I used cardboard to test the angles and find the ideal combination for the robotic arm.
The next step is to sent the file to be laser cut and assemble the pieces.