http://labs.minutelabs.io/Chaotic-Pendulum/
Read about double pendulums:
https://en.wikipedia.org/wiki/Double_pendulum
Mathematica Double Pendulum demo:
http://demonstrations.wolfram.com/DoublePendulum/
Create a simple double pendulum assembly, or any other gravity driven system that you want (if there is something to create for your semester project, you can make that - just create a dynamic simulation of something).
Base:
Extrude 0.5
circle diameter = 0.5
Start a new 2D Sketch at the end of the pole
Notice the orientation of the rectangle - you do not want the pendulum to swing into the pole!
Extrude
Create a 2D sketch on side of hole
Rectangle → construction line
construction lines → to mark center of rectangle
Circle 0.25
Make the upper arm of the pendulum:
Note create your own design for this, have fun with it! Just make sure that the ends fit together.
Having trouble extruding? Right click → Close loop
Having trouble with fillet edge? choose a smaller radius
You do not have to cut a hole in the center or add ribs etc. Do something fun with it - add your own design!
Create a new centered working plane
Semi-circle → Revolve
or create a cube or anything else you want for the end!
Save second arm
Open up an assembly:
Place each of your arms
Constrain base so that it does not move
Constrain arms to base
2 constraints → face to face, then axis to axis
If you tug on the arms they should move correctly.
Environment→Dynamic simulation
Simulation Player
red box - you can only edit while in construction mode.
while in construction mode
right click on gravity → click on the edge of your base in the direction you want gravity to be in
Define g = 3.86220 (A smaller value of gravity will slow everything down a little so you can see it better)
Simulation settings →Notice the joints that have been automatically created based on how everything is constrained together.
Open up output grapher, right click on trace, and add a trace.
Click on the end of the pendulum, or whatever point you want to monitor.
Run the simulation, graph out positions, velocities, accelerations of point you selected.
Base:
Extrude 0.5
circle diameter = 0.5
Create a path that is on a perpendicular plane to the circle for SWEEP
10X5X1
SWEEP
Profile = Circle
Path = 10X5X1 line
Start a new 2D Sketch at the end of the pole
View → Slice Graphics
Make sure that you are drawing on the right side of the pole!
Notice the orientation of the rectangle - you do not want the pendulum to swing into the pole!
Extrude
Create a 2D sketch on side of hole
Rectangle → construction line
construction lines → to mark center of rectangle
Circle 0.25
Save the base of your pendulum:
Open a new part:
Make the upper arm of the pendulum:
Note create your own design for this, have fun with it! Just make sure that the ends fit together.
Having trouble extruding? Right click → Close loop
Having trouble with fillet edge? choose a smaller radius
You do not have to cut a hole in the center or add ribs etc. Do something fun with it - add your own design!
Assign a material to it (Stainless steel shown below)
Tools→Material
Save the first arm
Then Save your arm under a new name
2 files - arm1 and arm2
modify the end of the second arm to be a ball (or anything else of your choice)
Semi-circle → Revolve
or create a cube or anything else you want for the end!
Save second arm
Open up an assembly:
Place each of your arms
Constrain base so that it does not move
Constrain arms to base
2 constraints → face to face, then axis to axis
If you tug on the arms they should move correctly.
Environment→Dynamic simulation
Simulation Player
red box - you can only edit while in construction mode.
while in construction mode
right click on gravity → click on the edge of your base in the direction you want gravity to be in
Define g = 3.86220 (A smaller value of gravity will slow everything down a little so you can see it better)
Simulation settings →Notice the joints that have been automatically created based on how everything is constrained together.
Open up output grapher, right click on trace, and add a trace.
Click on the end of the pendulum, or whatever point you want to monitor.
Run the simulation, graph out positions, velocities, accelerations of point you selected.
Adding constraints:
Right now, my pendulum can go through the bar that is holding it up. Let's add a constraint to fix this:
Hit the construction button on your simulation player, then select "Insert Joint:
You can click on any of the constraints, and see an animation of what type of constrain it is - have a look around at all the different constraints, then choose 3D contact.
Select component 1:
Select component 2:
Run the simulation with the pendulum starting in a high position:
Notice that now your pendulum will bounce off of, rather than travel through, the bar that is holding it up.
Play around with it! Look at the velocity and acceleration graphs, or create some new systems to play with!
Nice tutorial to watch:
(go through the entire series)
Turn in all parts and assembly to dropbox (not just the assembly!)
Think about your group project!
:
