Rotating Double Helix From Leftover PVC and Skateboard Bearings

With this instructable you can turn some leftover materials and turn it into a cool rotating Double Helix shape (DNA shape)

• At least 5 feet of 3/4 " PVC Pipe
• 12 foam balls
• 2x4" piece of wood 1' long
• 3/8" dowel cut to about 1'
• 2 Skateboard Bearings

Tools

• Drill w/ 3/8" and 7/8" bits
• Clamp
• Hot Glue Gun
• PVC cutter
• Measuring Tape

Mark the PVC pipe about 8" down from the edge, and cut it there, and then use that piece as a reference to cut another PVC piece. Repeat this process untill you have six pieces of approximately the same length.

Next, hot glue one foam ball to one end of each PVC pipe, and then go back through it again adding one ball to the other side of each PVC pipe, so that the glue from the first ball has time to cool before you add another ball to that piece.

Thirdly, pick a piece and clamp it down. Use a tape measure and pencil to find the middle and mark it, then begin drilling with a 3/8 inch bit. Be sure to go slow at first, because if you max out the speed of the drill from the very beginning, the bit won't bite, and the drill will slide off the edge of the PVC. Repeat this process with the other five pieces until they all have a clean hole straight through the middle.

Using a straightedge and a pencil, draw a straight line from one corner of the 2" x4" x 1' piece of wood to the corner opposite from it on the largest side, and then do the same thing on the opposite side. The very middle of the piece of wood is where the two lines intersect. Place the center of the skateboard bearing on the point where the lines intersect, and then trace the outside. Then, using the 7/8 " drill bit, drill a hole that is about as thick as both of the skateboard bearings stacked on top of each other. Clean the hole out, and put a bearing in to check that it fits perfectly.

Put the two bearings on one end of the dowel, making it so that the end is flush with the rest of the bearing, and then insert it into the hole of the base. If the bearings do not fit well and wobble, then take it out and add hot glue to just the outside, to make it stick in place. Then, add a piece of PVC onto the dowel, fitting the dowel throught the 3/8 " hole made earlier. Hot glue it in place about 1" from the base, parallel to the edges. Next, add the rest of the PVC pieces, about 1.5 inches from the one before it, and 20 degrees turned clockwise or counterlockwise, it does not matter as long as you are consistent, holding it in place until the hot glue dries. once it all is done, step back and look at what you made.