Step 2: Prepare the Balloon
I was worried that the latex balloon might have small pin-holes that would affect the rig’s ability to create a good vacuum. I decided to make a test. I inflated the two latex balloons I had purchased and put a clothespin on the bottom. The next morning I found that one balloon had deflated by half. The second balloon was still fully inflated, so I used it.
I filled the balloon with coffee. I chose the cheapest and coarsest coffee in the store. I think that a coarser grind would provide more jagged edges for the coffee granules to lock onto each other when the vacuum is applied. I didn’t test it, so it remains s theory.
I decided to only fill the balloon about ¾ full of coffee. When the vacuum is removed the coffee needs some room to become a flowing powder again.
Next I used a craft pipe cutter to cut off about 5 centimeters of the brass pipe. You can get pipe cutters from hardware and craft stores. You could also use a Dremel tool or even a hacksaw.
The aquarium tubing was pushed onto the brass tubing, and then the tubing was inserted into the balloon neck and locked on with zip ties.
I filled the balloon with coffee. I chose the cheapest and coarsest coffee in the store. I think that a coarser grind would provide more jagged edges for the coffee granules to lock onto each other when the vacuum is applied. I didn’t test it, so it remains s theory.
I decided to only fill the balloon about ¾ full of coffee. When the vacuum is removed the coffee needs some room to become a flowing powder again.
Next I used a craft pipe cutter to cut off about 5 centimeters of the brass pipe. You can get pipe cutters from hardware and craft stores. You could also use a Dremel tool or even a hacksaw.
The aquarium tubing was pushed onto the brass tubing, and then the tubing was inserted into the balloon neck and locked on with zip ties.
Remove these ads by
Signing UpFlag this comment as:
Not NiceInappropriateSpam
1
AJMansfield
says:
Mar 24, 2013. 6:00 PMReply
The more jagged edges you have, the more finely the grit is actually able to compact on itself, at least by one theory. Finer grit would be better, I think. The only thing it really has to have is sheer thickening (think cornstarch and water).
6
techiebot (author)
in reply to Apr 3, 2013. 8:52 PMReplyIf you read the article, the researchers discuss the optimum material that is fine but not smooth so that the particles grip onto each other. Their conclusion was that coffee grounds make an ideal material, and they are very light. I think your cement idea is interesting, but the material needs to be easily deformed so that when the balloon is pressed onto an object the material inside the balloon can "flow" around the object.
1
AJMansfield
in reply to Apr 4, 2013. 6:14 PMReply
Portland cement powder actually flows extremely well; when completely dry, it behaves very much like a liquid, actually. It will even splash up if you drop an item into it (it's far cheaper than coffee grounds, too: $5 gives you around 50lbs of it, which will fill 1-2 cubic feet of space). Plus, you can mix it with gravel, sand, and water to make concrete (if you want to be really fireproof, mix powdered fireclay with it).
Visit Our Store »
Go Pro Today »
