This is a simple connector to join two 2-liter bottles together to make a Tornado Tube experiment for your kids.
Fill one of the 2-liter bottles with water, connect, swirl, watch the tornado!
Steve Spangler Science sells these on his website:
After making one for my sons instead, I decided that others needed this as well. :)
You can see it in action here:
It is the simple colored connector that you see Steve screw onto the 2-liter bottles.
- Two 2-liter bottles
- Two 7/8" garden hose o-rings (hardware store)
- One print of this Thing
While the o-rings aren't "required," I like to use them as it makes for a more water-tight seal.
- Print using 2-3 shells for water tightness.
- Cut support material out of the center hole of the printed part.
- Insert a 7/8" garden hose o-ring on both threaded sides.
- Fill one of the two 2-liters 3/4 full of water.
- Screw this Thing onto the full 2-liter and screw a second 2-liter to the other end.
- Invert and swirl.
- Watch the tornado!
If you use the SCAD file to make alterations to this model, it also requires the "2LscrewPositive.11.stl" file from the "2 Liter bottle threads" thing found at http://www.thingiverse.com/thing:10489.
After publishing this, I found parkolay's "20_Oz_Bottle Adapter" http://www.thingiverse.com/thing:6090 that performs the same function. While they are very similar, mine will allow others to edit it via OpenSCAD. Also mine has a reducer in the center to make the tornado last longer while parkolay's does not.