4R Mechanism

Set the link lengths and the crank's position, velocity and acceleration get the velocity and acceleration diagrams.

Four bar mechanism
This html code uses "canvas" element, for which the positive x-axis is rightward (same as we usually draw on graphs), whereas positive y-axis is downward. Hence, in this system the positive angle is measured from positive x-axis clockwise. Similarly, positive angular velocity is clockwise and so does the positive angular acceleration.

Input the link lengths

Link 1 (Fixed link) Link 2 (Input link) Link 3 (Coupler ) Link 4 (Follower)

Input the quantities related to link 2 (angle, angular velocity and acceleration)

ϑ 2 ( degrees) |Ω 2| ( rad/sec) |α 2| ( rad/sec/sec)

Input scales for velocity and acceleration diagram

Scale for configuration diagram Scale for velocity diagram Scale for acceleration diagram

Output calculations

ϑ 3 (degrees) =
ϑ 4 (degrees) =
|Ω 3| (Coupler's angular velocity, rad/sec)
|Ω 4| (Follower's angular velocity, rad/sec)
|α 3| (Coupler's angular acceleration, rad/sec/sec)
|α 4| (Follower's angular acceleration, rad/sec/sec)

Click to draw the configuration, velocity and acceleration diagram