28 Apr 08
Originally posted by Kiwi kidIs this homework?
Does anyone have any good ideas for constructing a freestanding structure that will span 500mm out of only newspaper and cellotape.
The bridge must hold as much weight as possible 200mm above the ground and and structure cannot exceed 500g.
My pupils made Warren Girders from rolled newspaper (incredibly strong) then assembled the warren girders in pairs to make bridges. (Again joining with tubular paper).
The exercise demonstrtaed the strength of using tubes and triangles in construction.
A tip for joining two tubes is to use a smaller tightly rolled piece of paper as a joiner so that it sits inside both tubes - you can then bend this to whatever angle you want.
Good luck
30 Apr 08
2 edits
Originally posted by Kiwi kidTake long strips of tape, hold one end, and then twist the tape into a long twisted row of tape. You can now use the twisted tape as cables and make a cable stay bridge...or even a suspension bridge.
Does anyone have any good ideas for constructing a freestanding structure that will span 500mm out of only newspaper and cellotape.
The bridge must hold as much weight as possible 200mm above the ground and and structure cannot exceed 500g.
Plus it'll look way cool.
30 Apr 08
Originally posted by uzlessNice idea! A suspension bridge will be very fiddly - v. difficult to get all the lengths right. A cable stay bridfge (like the QE2 at Dartford) will be easier, maybe with just 2 or 3 stays? You will still need girders to make your actual platform rigid so get rolling that paper!
Take long strips of tape, hold one end, and then twist the tape into a long twisted row of tape. You can now use the twisted tape as cables and make a cable stay bridge...or even a suspension bridge.
Plus it'll look way cool.
01 May 08
The suspension/cable stay bridge is an an interesting idea. I have two questsions.
1. how can the cables (twisted cellotape) be strongly connected to the bridge?
2. How am i going to make the towers strong enough so they don't collapse when the bridge is loaded? If they are made of rolled paper they will be strong in tension but not under compression or bending.
01 May 08
Originally posted by Kiwi kidAre you doing any work on this?
The suspension/cable stay bridge is an an interesting idea. I have two questsions.
1. how can the cables (twisted cellotape) be strongly connected to the bridge?
2. How am i going to make the towers strong enough so they don't collapse when the bridge is loaded? If they are made of rolled paper they will be strong in tension but not under compression or bending.
1. Run a cable stay through one of your cylindrical girders and knot at end.
2. Tricky. Perhaps an arch bridge is better to take heavy weights? I dont think compression will be your problem but bending will be, (since a heavy book can easily be supported on paper columns because the weight acts stratight through the column.)
Good Luck