Introduction: Simple Tensegrity Set

About: I'm an architect by day. I love doing projects by night, both on my own and with my kids

This is my entry into the Chopstick Challenge.

Give credit where credit is due:
When I first started thinking about this challenge my first idea was to construct a tensegrity tower using chopsticks.   I did a quick google search and wouldn't you know....there was a instructable which did it better than anything I could do..

As an architect I've always been fascinated with tensegrity.  Tensegrity is a way of constructing using rods & wires.   Structurally it's brilliant.  the components are in pure tension and pure compression.
so for my entry what I thought I'd do is to create a construction set to teach my kids about tensegrity.  by creating a kit of parts, kids can create an infinite variety of structures.  the set can also be expanded with additional pieces and pieces of a variety of lengths.  just because of the time constraints I'm gonna stick with a single length rod and build a simple structure. 

I only had a couple hours to throw this together, and unfortunately I couldn't find chopsticks so I'm using 3/16" dowels.    I think these have the same properties as chopsticks so I hope you'll forgive my substitution.   I promise that when time allows I'll update the ibby with chopsticks.

Chopsticks - the more the merrier.  a minumum of a dozen.
wooden beads
rubber bands
electrical tape

utility knife
hand saw
cutting mat
spray paint  (if desired)
drill (if you need to drill out beads)

If you wanna see some models that are truelly amazing and much better than this check out:

Step 1: Cut Chopsticks Down to 6" Lengths

the first step is to trim down your chop sticks.   I do not have very big rubber bands so I'm going to keep the sticks 6" long.

After I had all my sticks cut down the next thing I did was to throw on some quick color.   I was really pressed for time so I just laid the sticks on paint table and hit with paint.   after waiting 15 minutes I rolled the sicks over and hit the other side. 

Step 2: Use Utility Knife to Cut Slits in Sticks

once you have all your sticks cut & painted to your licking the net step is to cut slits into the ends of each stick.

using a cutting mat and a sharp utility knife cut 1/2" slits into each stick.  when you cut the opposite end take care to align the cuts.   it probably doesn't matter but I think it looks better.  don't worry if the stick splits and your cut is longer than 1/2".

BE CAREFUL TO NOT CUT TOWARDS YOUR FINGERS!!!!!!   when you hold the stick hold it above where your cutting.  stick in the utility knife in at the slit end and pull towards the end of the stick away from where your holding the stick.   as a kid I cut my finger once and had to get stich's.  I was cutting towards my hand.  the blade got stuck a little bit, I naturally pulled harder, then it gave and blade jumped and cut my finger.  so always cut AWAY from your hand so that if the blade jumps you won't get cut.

once all the slits are cut, then take 2" strips of electrical tape and wrap it tightly around the ends of each stick just below the slit.  this will keep the stick from splitting once you it gets the tension of the rubber bands.

Step 3: Prepare Your Beads

ok,,,,, since I'm cheating and using dowels i got lucky with my beads.    I found wooden beads that had a hole that fit perfectly on the ends of the sticks. 

if you cant find this then you'll need to drill out the beads to fit the sticks.  since chopsticks taper you'll have to drill different size holes for each end.   I recommend find 2 different shaped beads (circles & squares).  then drill one kind of bead to fit one end and the otehr kind of bead to fit the other.

use pliers to hold the beads while your drilling so that if the drill skips it wont get your hand.   take your time so you don't split the bead.

Step 4: And Now...Start Simple

ok....I'm gonna start with a simple structure.  at some future point I'll update this with some more complicated structures.

start with 6 sticks.   if you have painted them different colors then pick 3 pairs of 2.
arrange sticks into "star" pattern and hold together with a rubber band as shown in photo.

now that you have the "star".  you'll need 6 rubber bands.  be careful that the rubber bands are all the same size.  if you use different size rubber bands they will pull differently and you'r final shape will be unbalanced.

take each rubber band and stretch it end to end on each stick so that it runs in between the crossing pair or sticks.  be careful to stretch the rubber band evenly so that the rubber band is in even tension on each side.   repeat this for all 6 sticks.   if the slits of the sticks looks like it might split you can put a wood bead on the ends to hold is together.

Step 5: Tie the Sticks Together

Now that you have the star shape with rubber bands streched from end to end on each stick it's time to tie it all together.
at the center of each rubber band where it goes between the crossing stick, strech it up to the end of the crossing stick.  
once you've connected it to the crossing stick, put a wooden bead end cap on to keep the tension from breaking the end off the stick.

repeat this for all the rubber bands.

Step 6: And Now It's Time to Cut the Chord.....

and now it's time for the big reveal.  simply take some scissors (or utility knife) and cut the center rubber band which is holding all the sticks together.   you're model will now spring to life.   if you've been careful and your rubber bands all have balanced tension then your model will be balanced.  if it's uneven then simply go around and find where the rubber bands have uneven tension.  remove the rubber band from the end and then replace trying to have even tension.    DON'T TRY TO PULL ON THE RUBBER BANDS TO ADJUST THE TENSION.  THE RUBBER BAND WILL BREAK (I LEARNED THAT THE HARD WAY).  with a little adjustment, and a little patience, your model will be balanced.


so that's it there's my chopstick model.....kind of.
I've seen this done with soda straws so I'm fairly confident that it will work with real chopsticks.