Tensegrity Structure By JZ (Joden & Zander)

This Tensegrity structure project was instructed to us by our Honors Intro Engineering Design teacher. This fun and easy project was to display Tensegrity in a cool demonstrative way. My partner and I decided to demonstrate this by creating a Tensegrity table. Through creating this Tensegrity structure we switched off creating each part which made this project easier and harder in various ways. Thus it made partner coordination imperative while creating our structure. Throughout this project, there were also many minor inconveniences that caused us to return to class some days just to get more in tune with the SolidWorks software we used to create our models. The final model was a height of 15.5 cm and width of 15cm. 

Assembly/Construction Instructions Section: 

Tools Recommended: Hammer, Small Phillips head screwdriver, two pairs of small needle nose pliers, 2 rulers, a leveler, clippers, a writing utensil(preferably pencil), superglue if necessary 

Tools Needed: 10 small hooks, 4 pieces of 25 cm long fishing line

Section 1(Assembling the arches): 

• To begin, make a hole by using a hammer and a Phillips head screw driver once you see the hole where your hooks should go in, try to screw in a hook. If the hole is too small take a small phillips head screwdriver and place it on the hole. You then want to take a hammer and lightly tap the top of the phillips head screwdriver until a big enough hole forms for the hook.
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• If you made the hole too big on the arch, it is recommended to use super glue to fill the hole to ensure the hook stays in.
• Take a hook and insert one into the arch.
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• Do these steps again for the other arch.
• Once you have done that you will want to connect the two hooks with a bowline knot. You can choose your preferred line distance, but we recommend around 4 cm. 
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Step 2 (Hooks in the bases):

Locate your premade holes on the bases. Once you find them try to insert a hook into them. If the hole is too small take a phillips head screwdriver and a hammer. Lightly tap until you can hand screw the hook in.

• Repeat for other base if needed. 

 Section 3 (Assembling your structure):

• Insert both ends of the legs into the bases 
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• Have someone(your partner) hold onto the arch while you get your fishing line. With a fishing line, you want to tie a bowline connecting the lower and upper hook on your bases. If you inserted the hooks on the bases properly the bottom and top hooks should be vertical to each other.
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• Repeat tying the bowline to the other 3 hooks remaining 
• When done, put something that's not too heavy on your structure. If you notice that there are lines that are slacking you should keep that in mind. After checking all the lines, tighten the line or lines that contain slack. You can do this by having your partner grab the end of the line of the bowline and you holding the line at the beginning. Once both of you pull the line it should shorten and get tighter at the same time. Repeat until you think you have a level of a tensegrity structure. 

• Once you think you have finished, put a leveler on the top of your structure. You want all the bubbles to be in the middle. If the bubbles are not in the middle, find out what lines you need to adjust in order to do so.

• Once you are sure you are finished, clip off the extra line. Make sure to give an extra cm or two in case the line loosens. 
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Design Choices: 

One of the major changes we made was moving the inserts for the arches on the base. We wanted it to be as close to the edge as possible in order for the arch to be bigger. As well as to reduce to curvature of our bases due to the fact that they were warping our edges. Though during our first version was not a problem we diagnosed it to be the filament or the 3D printer itself.  At first, we planned on doing a circle arch because our theme was arch/circular patterns. But we soon found out that it was very difficult to 3d print a circle arch. In order to overcome this we cut off both ends of the circle to make it have 2 flat sides. This allowed us to maintain the circular arch shape and have it made easier to print. 
 

Before 

After 

Instead of having a more semi-circle/circular arch, we changed it into a parabola. Doing so resulted in the height of our structure being raised therefore displaying tensegrity more effectively.  But, when we did make these changes the ends of the arch would not be horizontal anymore. In order to fix that we added a vertical construction line to set the arch equal on both sides. We then added a  horizontal construction line across the base to have a reference point to make sure it was flat.

←Version 1.0 Semi Circle Arch

 ←Version 2.0 Parabola

• On our base and arch, we also decided to add holes where we would insert the hooks. We did this because, in our Version 1.0, we had to create our own holes. Creating our own holes too sometimes provided errors with the holes being too big forcing us to use hot glue or super glue to fill the holes to ensure the hooks stay in place. 

We also found that we would like to change the font style on our arches. We find that the font style is nice but we are having some minor complications when the font is printed out. Therefore we will be making the adjustment to a more defined and simplistic font.