This instructable shows how to make a working drop spindle, lazy kate and niddy noddy out of K'nex, A drop spindle is a tool for spinning yarn or thread from fiber, like wool or cotton. A lazy kate holds multiple spools or spindles of yarn and allows them to turn freely so that the strands can be plied together. A niddy noddy is a traditional tool for winding a skein of yarn. This instructable does not teach you how to spin. There are many excellent tutorials on the web that teach how to spin on a drop spindle -- but you should look for one that demonstrates with a bottom whorl spindle, not a top whorl spindle, since that is the kind we'll be making here.
Step 1: Making the drop spindle's whorl
The first step to making a drop spindle is building the "whorl" or disk at the bottom of the spindle that acts as a flywheel to keep the spindle turning. There are many ways to do this. I've shown a few of them here. Feel free to play around and come up with your own designs.
A couple of things to consider when designing the whorl are radius and weight. If the radius is too large the whorl may bump into things (like your leg) while you are spinning. If the whorl is too heavy it could break a fine thread, but if the whorl is too light it will stop turning quickly and you will be constantly having to flick it to keep it going.
It isn't actually the weight of the whorl that determines how long it turns -- it's the moment of inertia. Physics teaches us that if you want to maximize the moment of inertia of an object of fixed mass, that mass should be distributed as far from the center as possible. So the ideal whorl would have only thin spokes connecting a heavy rim to the center.
All of the whorls shown here work just fine.