Aim:
To create a horizontal structure spanning 25 cm with the specified materials that will provide support for as much weight as possible.
Bridge 1: The Adaptor
Sate sticks and hot glue
Estimated weight: 100g
Hypothesis: 6 blocks (1500g)
Fail: when 5th block was added (1250g)
Starts bending at 3 blocks (750g)
Left side gave way at 4 blocks (1000g)
Right side gave way at 5 (1250g)
Method of Construction:
Two sets of four sate sticks were glued together using hot glue to create two beams. An additional four sate sticks were joined together using hot glue, which was then divided into four segments. One segment was attached either end of each beam at an outward angle to create legs. Under each beam was two singular sate sticks which created triangular supports. Finally, to create a bed to hold the tray, six sate sticks were added horizontally connecting each side.
Description:
Bridge one was constructed using sate sticks and hot glue, with the intention to provide horizontal support of SIX 2.5kg paper weights. The design proved effective whilst holding the first two paper weights. It wasn’t until the third paper weight was added, that bending on the left leg occurred, forcing the bridge to tilt slightly to the left. When the fourth paper weight was added, the left leg completely gave way relying on the support of the table, whilst the right leg remained unsteady and strained. Once the fifth paper weight was placed (slightly to the right, to even the loan), both legs gave way and slipped outwards to either side onto the table.
However, once all paper weights were removed it should be noted that the design proved adaptive to the given load forced onto the structure, as it bounced back to its original form after failure. This is believed to have resulted from the flexibility of the hot glue and the use of squares rather than triangles between the legs on each side.
Possible Improvements:
Adding more support beams creating triangles as the structural geometry.
Bridge 2: The Ballista
Sate sticks, elastics, fishing line
Estimated weight: 120g
Hypothesis: 2 blocks (500g)
Fail: when 2nd block was placed. The anchor points of the support towers started to lift upwards causing the structure to fold in upon itself.
Was able to hold one block of paper
Method of Construction:
The two side support towers consisted of three beams that joined at one point with an elastic, triangular support was then added between each beam and elastics joined at the bottom to allow for flexibility of weight. The triangle mesh was formed by weaving the sate sticks in the X and Y direction with a pinpoint joints (made with elastics) at each intersection, then additional sate sticks were woven in the XY direction to create a triangular structure. The connection between the two bases were thick sate stick beams.
Description:
Bridge two was constructed using sate sticks, elastics and fishing line, with the intention to provide horizontal support of TWO 2.5kg paper weights. The design proved effective whilst holding the first paper weight. It wasn’t until the second weight was added, that the bridge quickly collapsed and imploded. This was caused by the anchor points (on each support tower) which started to lift upwards when the force was increased.
Possible Improvements:
Adding weights/support system to the sides of the structure to prevent it from collapsing into itself
Bridge 3: The Grain
Only Paper
Estimated weight: 125g
Hypothesis: 6 blocks (1500g)
Fail: after bouncing up and down on it repeatedly, on the left side of the bridge, at the contact point between the bridge and the table, a slight crease in the paper was formed which caused the structure to slip from the edge of the table.
The process of repeatedly rolling the paper created a very effective structure enough to hold the weight of a person.
Method of Construction:
Repeatedly rolling paper as tight as possible then rolling about 20 of the rolled papers within another paper. Repeating this process three times to create the bridge. These three beams were then rolled up into one unified bridge. When placing the tray on top it was noted that it was unbalanced, so the three beams were then spread out at regular intervals to create a more stable platform for the tray and weights.
Description:
Bridge three was constructed using only paper, with the intention to provide horizontal support of SIX 2.5kg paper weights. The design proved effective throughout the whole process of adding all six paper weights. It wasn’t until we got a volunteer to sit on the bridge with a repeated pushing down force that caused the bridge to collapse in itself.
Possible Improvements:
To extend the length of the bridge so that the amount of paper on the table is increased, reducing the chances of a small crease that would create the bridge to slip and implode from the edge.
Note: This was a group activity with Catherine Erzetic and Harris Paneras.