Kirby Tensegrity Table

Image Section:

Summary:

The tensegrity “floating table” is a fun and interesting project to build and impress your friends with. Using weight distribution and cool design choices you can make your magic table into anything! This project is dimensioned to fit in a 20x20x20 cube, so it is portable and cute! You can create this to be a sturdy stand, an interesting decoration, or whatever else you want!

Lesson Plan:

For this project, our task was to design and create a single custom Tensegrity Structure with some amount of complexity while also focusing on collaboration with a partner and utilizing the features of Solidworks.

Parts List:

Modeling Instructions:

Sketch of Star (2):

• Start by making a constraint box of 20cm x 20cm
• Make a pentagon shape centered around the origin. Each side measures to 5cm. 
• Make a construction line from the midpoint of each side of the pentagon to the edge of the constraint box. (roughly 7cm)
• Create a triangle from those points
• Set all triangles equal to each other

Top Star: 

• Create a rectangle in the center of the star
• Dimension the rectangle to be 1 x 0.55cm
• Have the rectangle be 4cm away from the bottom of the star
• Make another rectangle that is in the center of the star
• Dimension this to be the same size as the other rectangle
  • This will attach the top swirl

Bottom Star

• Create two rectangles of 1 x 0.55 cm 
• Set each rectangle to be 1 cm from the nearest corner of the star
• Set the two rectangles to be 7.23cm away from each other
  • This will attach Kirby’s legs!
• Create another rectangle
• Center the rectangle and dimension it to be the same size as the others
  • This will attach the bottom swirl

Sketch of Kirby (Top)- 

• Create a constraint box of 20cm x 20cm
• Create a vertical construction line at 10cm
• Create a horizontal construction line at 8.25 cm
• Create a half circle with an R=7.25cm and a length of 14.5cm in alignment with the origin.
• Create a semicircle or arc with R=2.5cm 
• Create an oval (vertical) with a length of 3.5 cm
• Set the width to 1.4 cm
• Set the oval to be 1.5 cm away from the mid-construction line
• Create another oval within the shape, roughly about half
• Set the length of this oval to 2cm x 1.4 cm
• Create a slightly diagonal oval
• Set one side (farthest left) to be 0.75 cm away from the bottom
• Set the other (farthest right) to be 1.2 cm away from the bottom
• Set the oval to be 1.7 cm away from the corner of the top half
• Create an arc from the left corner to roughly a little less than halfway up the top
• Set the width to 4 cm
• Set the height to 3 cm
• Select the eye, blush, and arm to mirror over the horizontal construction line
• Fiddle with measurements to make accurate
• Cut out the excess mouth 
• Attach peg to the very top of the Kirby head d=0.50cm circumference

Sketch of Kirby (Bottom)- 

• Create a constraint box that is 20 cm by 20 cm
• Create a vertical construction line at 10 cm
• Create an arc that is 14.5 cm in length
• Create another arc that is 5.5 cm (width) x 5.3 cm (height)
• Dimension the arc to be 4.25 cm away from the left side
• Create a construction line 1 cm to the left of the origin through the sketch
• Create an arc from the previous construction line to a little under the mouth shape
• Make a horizontal construction line from the midpoint of the arc to the vertical construction line
• Dimension that to be 3.9 cm
• Dimension the arc to be 3.5 cm (height)
• Dimension the top corner of the arc to be 5.7 cm from the top of the sketch
• Dimension the 1.37 cm measurement
• Select the leg to be mirrored over the midpoint construction line
• Cut out the excess mouth
• Attach a peg to each leg with d=0.50cm (one on each side centered

Swirly Things Sketch- 

• Make a constraint box of 20cm by 20cm
• Make a vertical construction line at 10 cm
• Create a line on the bottom that is 2.5 cm on each side of the construction line
• Create a very wonky arc roughly the shape shown
• Dimension the vertex of the arc to be 1.7 cm from the midline
• Create another wonky arc similar to the shape shown
• Dimension the height of the shape to be 10.65 cm 
• Fiddle tremendously to make a fluid perimeter

Assembly Instructions:

Step 1: Prepare all the tools listed below 

• Small Phillip Head Screwdriver (#000-#0)
• Hammer
• Ruler marked in millimeters
• Pencil
• Glue gun
• 12 small hooks
• Fishing line or a thin string (will be connecting them)

Step 2: Take the two bases, and connect the hooks to the top and bottom bases.

1. Grab a ruler and a pencil, measure 2 cm from each of the vertices of the star base and draw a line. Try to make the line located at the center and be an angle bisector. 
2. After measuring the 2 cm line, place the hooks at the endpoint of each line, and there will be 5 hooks for each base.
3. Using the tip of a small Philip head screwdriver, make 5 small holes in the base at 5 points where the hooks will be placed. This step involves lightly tapping the handle of the screwdriver with a hammer, making sure it doesn't go all the way through, but still with a force that’s strong enough to make a hole.

1. Place the hooks in place of the five small holes and first press down firmly with your fingers to make sure they stay in this position. Then, twist using pliers. Make sure they do not go through the base. 

1. Do the same thing for the top base, so there are 10 hooks in total for the bases.

Step 3: Place the hooks on the swirl structure

1. Use the measure tool on Solidworks to make a rough measurement, make sure that the hooks on the two swirls are on a horizontal straight line, and mark this position with a pencil to facilitate subsequent operations.
2. Just like punching holes in the base, we have to do the same in the swirls. Use the small screwdriver to make a small hole, making sure it holds the hooks roughly in place. 
3. When placing the hooks in small holes, first press them down to allow them to stand on their own and then use a hammer to hold them in place: Hit them with a hammer to make the holes deeper. But don't penetrate the bottom.

• As we were doing it, we were pushing too hard and the hooks went through the bottom. In this case, hooks cannot be fixed. So we had to use the glue gun to fix the hooks to keep their cohesion with swirls.
• The general conclusion we came to is to push the hooks to about half the depth so that they can be fixed without penetrating the bottom.

1. After the hooks are in place, use a plier to twist them and make them tighter. And be really careful just so it won’t go through the bottom.

Step 4: Connect the swirls with the bases.

1. First, differentiate the bases and the proper holes for the swirls. On each base, one hole will be for the swirls while the others will be for the Kirby pieces. The top star has only 2 holes while the bottom has 3, two of which are for Kirby. 
2. When connecting the swirls, use sandpaper and a sharp tool to cut to trim off excess material off the pegs to fit in the holes
   1. There will be excess material because the printer doesn’t always print exactly, and we’re dealing with 0.03 or 0.04 cm of a difference
3. Fold your sandpaper to have a straight edge and run it along the corners and faces of the peg, shaving off material

1. If needed, snip off the corners of the peg to better fit into the hole
   1. If the hole and peg are widely different, don’t be afraid to use a sharp tool and sandpaper within the hole as well
   2. Be more careful sanding down or cutting the bases because it could break or too big of a hole could be created

1. Once the proper size, fit the pegs on the swirl pieces into the base (REMINDER: The bottom base has 3 holes while the top base only has 2) 

1. Fit the pegs into the proper holes in the bases, and secure them with hot glue if necessary

Step 5: tying the strings between the two swirls.

1. After connecting the two swirls to the corresponding bases, We need to connect the hooks on the two swirls together.
2. Take a string of about 10-15 cm (you can cut off the excess later), and have one person hold the two swirls just so they are parallel and one is directly under the other. 
3. Place the string in the hook and tie a knot ( a fisherman’s knot will work well because it is secure and fast to tie).
4. After ensuring that the hooks of the two swirls are on the same level, extend the string that ties the upper hook down and through the lower hook, and also do a fisherman’s knot.
5. Make sure the string is taut and approximately 4 cm in length between the hooks

Step 6: Tying the rest of the hooks together

Like before with the swirls, take a piece of string/fishing line and place it within a hook on the top base, securing it with a fisherman's knot. This string can be between 25-30 cm to allow for excess to make the process easier

Have one person hold the top base, making sure it's level with the bottom and a proper distance away. Then, tie the string to the coordinating hook under the first base, making sure the string is taut and straight, with no unnecessary knots or twists. 

Secure further by using the pliers to pull the string more

Repeat this process for all five hooks on each base

1. When doing this, it is important to try to make each string as even as possible, and also quite tight. If the string loosens it will lose the tension aspect that allows for tensegrity
2. Feel free to make adjustments as you go! You won’t get it perfect the first time and will need to adjust the strings to be more even with each other
3. Also, remember that in total the stars should be approximately 20 cm apart

Step 7: Achieve Tensegrity! Good job!

1. Once all strings are even, taut, and the bases are level you have successfully achieved tensegrity!
2. Pat yourself on the back and test it out!
   1. You can place a variety of items on top of the structure to test its tensegrity abilities (phones, calculators, tools, etc) 
   2. This is also a good way to know where the weak parts are within your structure so you can go back and fix them later

Design Choices:

1. The first step in our design choices was to create a sketch of what we wanted Kirby to look like as well as the other pieces. 

1. Next, it was time to make step-by-step instructions on how to create this sketch on Solidworks! 

1. Then, it was time to move on to Solidwords! Solidworks is the program my partner and I used to create the 2D and 3D models of our designs. I worked on the 2D model for our Kirby while my partner worked on the stars!

1. When those were completed, both of us worked on making the swirls. 
2. After all of our parts were done, we put them into an assembly and mated them together to see how everything worked

1. We then attached hooks and strings to mimic the actual construction process

1. Once finalizing the assembly, we printed our parts and made our first version of the Kirby Tensegrity Table! (Kirby not included in photo)

1. After further revision, my partner and I identified some problems
2. We decided to round out the shape of the stars, and to fiddle with the measurements of the placements of the holes for the pegs

1. We also decided to make our swirls a bit thicker since during the construction process they split due to putting the hooks in. We also added some designs to the hooks to make them more interesting to look at. 

1. After making these revisions, we decided to add some additional artistry, starting with smoothing out the edges on the kirby as well!

1. After all of our revisions we updated our assembly and mated all of the pieces together once again.
2. Once printed here is what a few of the individual pieces looked like. 

1.  Once the version 2 parts were printed, we assembled them as we did in the assembly instructions and completed our Tensegrity 2.0!