| Table of Contents |
|---|
Iteration Documentation
Our team initially wanted to use a quick return slider mechanism but was advised against that because prismatic joints are hard to get working in real mechanisms. Instead, we decided to use a Peaucellier-Lipkin linkage to help achieve the up-and-down shaking motion. The initial design was made in motion gen to get a feel for how the links would interact. Then the CAD model was made to map out link lengths that we wanted to use. Then we created a prototype out of popsicle sticks to get a real-life view of the motion before moving on to our final prototype.
After multiple prototypes, our team discussed how to create the angle change in the shaking motion. Initially, we thought of laying the linkage flat and adding something underneath to lift the entire plate up and down. Ultimately we decided to turn the linkage so that the shaker would sit horizontally above the ground and add a cam below the plate to help change the angle of the linear motion. We created a stand that would allow the linkage plate to stand upright and allow for space to hold the cam underneath the the plateplate. We also designed a simple shaker holder that features a shelf to keep the shaker level.
Initial Design
Below is a 2D model developed in Peaucellier-Lipkin linkage which can transform rotational motion into a perfectly linear motion and the CAD model with final dimensions.
| 2D Motion-Gen |
...
| Model |
...
| CAD Model |
...
|
|
Rough Prototype
We made our rough prototype using popsicle sticks, screws, and nuts. We mounted it by holding the grounded joints to a table with clamps. We did not incorporate the crank in this iteration, and therefore ran it backward by actuating the output joint.
...
|
|
2nd Design
Cam Design
...
Shaker Holder Design
For this mechanism, we chose to go with a plastic toy cocktail shaker because it was smaller and lighter. We also decided to use a press fit to decrease 3D printing material and time. In the second design, we thickened the arms to increase the structural integrity.
| Initial Design | Second Design |
 |
|
Second Design
Our second iteration of the mechanism has a crank or cam mechanism to rotate the entire linkage plate. A pivot point is needed on the edge of the linkage plate to rotate about. This is how we incorporated an angle change.
Stand Design
The stand design features two plates connected through a shaft which is the pivot point of the plate. The linkage motor is attached directly to the linkage plate to help add weight and keep the plate in contact with the cam. The cam motor is then mounted to the back plate of the base.
Cam Design
Our team decided on a cam to move the linkage plate. Initially, we had a 14 cm diameter (~5.5 in) with a groove that would keep the bearing in line with the Cam and prevent misalignment. The cam was 3D printed and we found that it was too big, so we decided to create a 1.25 in diameter Cam that was laser cut due to time constraints.
| Initial Cam (Diameter = 14 cm) | Second Iteration of Cam (Diameter = 1.25 in) |
|
|
