Okay,
Here is an exercise for this “rainy day” (meaning we can’t go outside and sodaplay) of constructing. You can’t save your work, but saving isn’t as important as knowing how to perform construction tasks again and again so maybe it is for the best.
I bet people would like to use some of the complex spinning motors they see in the zoo. In fact, the zoo would be a better place if everybody knew how to properly anchor and implement these motors.
I can’t save a custom example to my “example” account so use this pre-existing counter rotor:
http://sodaplay.com/constructor/player.htm?&getmodel=warptera+4pt_Angle_Counter_Rotor
Like I said a few minutes ago in the “sodazoo” thread, this motor looks funky, but it works exactly like the old counter rotors in the sense that there are two circles of masses rotating along the same path in different directions.
By anchoring one circle (or “side” of the motor) to a frame, the other side can spin freely while supplied with the necessary leverage to push a larger mechanism.
Begin by making wave speed zero. Now manually advance the wave to make sure that all eight power points of the motor are easily differentiable and don’t overlap.
Now go into “construct” mode and create a perfectly horizontal fixed spring stretching from left to right, above the motor. Now create five vertical fixed springs that all intersect the horizontal line at roughly even intervals. Don’t worry about their placement, they will be moved shortly.
Now go into simulate mode again. The wave should be at max amplitude but zero speed, g = zero, k = ~80%, while f=~60%.
[warning: this step can be frustrating at first] now examine the motor and Identify two masses in the power ring of the motor that are directly across from each other. It doesn’t matter which pair, just make sure you choose an opposable pair that are sufficiently clear of the linear motor parts. Move the motor up to the guideline (toward the left side) and position the two masses right on the horizontal guideline. Sometimes it is tough because the opposite mass will tend to move when you shift the other. Just be persistent.
Now place two of the vertical fixed lines so that they intersect the horizontal line exactly where the masses are sitting. Now that your guideline is fixed remove the motor. If done correctly you have now created a single guideline with the exact length that exists between the two masses at all times during the motion of the motor.
Now go back into “construct” mode and place two free masses on the intersections that constitute your new guideline. Once they are perfectly placed, connect them. Now you have used your guideline to create a spring that has the exact length between the masses in the motor.
Now go back into “simulate” mode. Use the spring you just created to make divisions on the horizontal guideline equal to the original length. You will have to be just as patient as when you placed the motor on the line. Use higher friction if it vibrates too much.
When completed you should have a single guideline with five vertical divisions all equidistant to each other. This has created a distance exactly equal to 4 times the distance between the masses in the motor that you originally measured.
Now discard the short measuring spring or delete it preserving the masses because you now need a longer spring. Using the large guideline, make a spring that is equal to 4 times the original length. This length will be the long length of the tension spring.
Now you must attach each of the end points of your long spring to one of the two original masses in the motor with springs of zero length (place them exactly over each other and click until it creates a “zip” spring). Once that is done, zip the two masses from the motor together as well.
If you have done everything correctly (and if I’ve explained it correctly), you should go into “simulate” mode and see the motor just as it was, excepting the large “spike” going through it. This tension spring can be used to attach the motor to a frame, while still allowing the other half of the motor to spin unimpeded.
There are many examples of this technique in the zoo. There are many possibly configurations for the tension spring such as placement, # of masses etc. Please enjoy your new skill and enjoy the new possibilities it provides.
Please post if any of this is unclear or if you have further questions.
Best,
w
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