12.4 Kinematic Analysis
Top Plate: Slider-Crank Cutting Section
The following graphs depict the slider block (l4) position, velocity, and acceleration over our range of motion of input angle from 160° to 135°.
As we see from the position analysis plot, the slider block moves about 6mm with θ2 ranging from 160° to 135°, which ensures an effective cut on the lateral can surface.
As we can see from the mechanical advantage plot, the mechanical advantage ranges from 4.7 when the blade touches the can to 2.1 at the system’s final position. With a servo motor providing a maximum torque of 4.5Nm, the force ranges from 528.75 N to 225 N, which is more than sufficient to cut a can on the lateral surface.
Bottom Plate: Clamping
The bottom plate has two mechanisms, the clamping and the rotation. The rotation doesn’t need any kinematic analysis done for it as it only needs to apply slight rotations in a 2-gear system, so the rest of this part will focus on the clamping. The main focus on the clamping is right when it touches the can as to achieve maximum mechanical advantage and force to keep the can from slipping or moving when the can is either rotated or cut into from the top.
This moment is achieved when Link 2 reaches 287.75, so we want to analyze the Force output when it reaches this angle. The first step is to find the position, velocity, and acceleration of Link 4.
This leads to being able to find the output force if being applied by a human with 2 Nm of torque giving us an output of 270N of clamping force, enough to secure the can as long as we also apply frictional forces with a strip of sandpaper.