Designing a Herculean Chair: Seeking Cardboard Ideas

[DaveDanClay]

A group of us three are designing a "Herculean Chair" for Physics class. The chair must be made entirely out of cardboard, and the chair should be able to support 250 pounds. (Tape, staples, w/e can be used.)

We are looking for some ideas on how to go about doing this, any type of cardboard to use, designs, etc.

Thanks,

DaveDanClay

 

[jcsd]

Use corrugated cardboard as it is much stronger, also make sure that you include plenty of diagonal struts to help support the weight.

 

[DaveDanClay]

What kind of glue do you guys recommend? Rubber Cement? Elmers? etc? It is for attaching sheets of cardboard together.

 

[jcsd]

Originally posted by DaveDanClay
What kind of glue do you guys recommend? Rubber Cement? Elmers? etc? It is for attaching sheets of cardboard together.

I don't know, wood glue perhaps? Try experimenting with joints glued together with different glue, also try to maxmize the surface area of the joints.

 

[DaveDanClay]

Will Do!

Thanks

DaveDanClay

 

[HallsofIvy]

Critical point is not so much what kind of glue but that you make everything below support everything above. Include LOTS of triangles- rectangles won't support well. Lots and lots of cross members.

 

[DaveDanClay]

What exactly do you mean by cross members?

 

[Greg Bernhardt]

One of my friends did this project with very little glue. He built the chair using a lot of cross member pieces that fit together, the result was a very strong bottom in the shape of an arch.

 

[Artman]

Originally posted by Greg Bernhardt
One of my friends did this project with very little glue. He built the chair using a lot of cross member pieces that fit together, the result was a very strong bottom in the shape of an arch.

Yes interlocking pieces rather than glue. Also, cardboard bent into at least 90 deg angles will be stronger than straight pieces.

 

[Jug]

Yes, arched legs might be good. If triangular, I suggest an angle of 50.625 degrees and multiple of 8 inches long.

 

[Jug]

Thinking on it, I'm 'inclined' to think that incorporating both methods might be the ideal - arched legs with the given angle as bracing to either ends of the curvature. I have lots of bamboo and given the time will make a model. Let us know how you make out with yours.

 

[NateTG]

Cardboard has great compressive strength, but relatively weak tensile and shear strength.

If you don't care about making it pretty, you can take two cardboard plates - one for the sitting surface, one for the floor and then populate the middle space with vertical pieces of cardboard bent into W's, and then wrap it with the outside of a carboard box.

If you're looking for *strong* glue, you could do a lot worse than contact cement.

Your most likely failure points are:
1. Joint Failure -- You should try to have strong connections on joints. Figure out how to make strong connections before you plan you design.

2. Overambitious design -- Keep it simple. Make sure you finish. Stay away from destructive testing.

3. Wet cardboard -- Unless you're using paper machee you should probably stay away from wet cardboard.

 

[DaveDanClay]

I suggest an angle of 50.625 degrees and multiple of 8 inches long. [/B]

how did you come up with that angle measure?