Hand-Operated Mechanism
The mechanism above is the final prototype of my hand-operated mechanism. The backing has a light etching of the name of the mechanism, Crank Rocker, with arrows saying “fast” and “slow” in opposite directions to demonstrate the nature of the quick return. The backing has a bigger circle cut out that I glued onto the back of the circle in the backing. This was done to keep the inner circle in place while also creating a track for the head of the screw to move through as the machine is rotated.
3D Printed Handle
The handle I printed is based on the measurements shown in the screenshot below (in mm). The sketch was rotated around a center axis to create the gray shapes shown below. I created one and copy and pasted a second one to make two halves. The circle was created to act as a washer to secure the handle onto a screw. Instead of using this, I used a stack of circles I created for the last version that contains a nut within the handle. This nut is embedded into the stack and is able to be screwed onto the screw that moves around in the circle track. The original handles that I 3D printed ended up being too big in size. I had thought that the sizing was proportional to my mechanism but they took 12 hours to print and were 10X the size that I needed. These are the blue and yellow handles shown in the picture below, in comparison to the handle I ended up needing.
Acrylic Components and Automated Mechanism
The arms of my mechanisms were printed out using the fusion file below. Each arm has a width of 20mm, with various lengths. These pieces were cut out of yellow acrylic. The rectangles in the screenshot below were used to create distance between the two backings for my automated mechanism. These were cut out of neon green, the same acrylic that was used for the backing.
The base for the completed automated mechanism is shown below. This is the file seen in Ruby with the colors relating to the operation of the laser cutter. The red shows which areas are etched while the blue shows which areas were cut. Similar to the hand operated, the automated backing shows arrows etched with the name of the mechanism etched in as well. The arrow pointing to the left is shorter than the arrow pointing to the right, demonstrating the quick return.
Below is the link to a movie of my mechanism operating with the arduino.
Finally, the servo code used to operate my mechanism is below, with a picture of the finished product to the left.
