Public Lab Research note


Use of velcro ties in Balloon mapping

by eustatic | September 16, 2014 05:35 | 2,321 views | 9 comments | #11143 | 2,321 views | 9 comments | #11143 16 Sep 05:35

What I want to do

Get past zip ties, and suggest that the cowardly balloon mappers among us use re-useable velcro ties for checking the tension or "lift" on the balloon to see whether we've filled it enough.

or we could use the Dosemagen tie-a-bunch-of-string-around-the-balloon-neck-and-everything-else method. I think I bought these at Lowe's, but i've seen them for cheap on amazon in packs of 100 or something crazy like that.

zip ties have to be cut, unless they are the reusable kind; this creates some consternation if you under-inflate the balloon, which I always do. Once you measure your lift, and find out you've under-inflated the balloon (again), there's always that 5 minutes spent cutting the first zip tie, and the worry that the scissors will pop the balloon.

well, no more! this time, we used a velcro tie as a temporary tie until the balloon was inflated to the proper lift.

My attempt and results

15217329745_466c6c0401.jpg

it worked. we inflated the balloon to almost enough, then secured the velcro tie to check the lift. We measured the lift, found it wanting, then we took the velcro off to add more helium. This also gave more students the chance of inflating the balloon.

Although i went ahead and attached a zip tie for redundancy for the washU high altitude flight, I probably didn't need it. The wind was gentle this day, so while this was not a real stress test, I'm fine with that.

I recommend that you consider the use of velcro ties. very handy.

Questions and next steps

I do not recommend Ben's towel pants. He just looks uncomfortable.


9 Comments

lets see if we can source some of these and do force tests on them. We just switched out the swivels for better ones, I'm into continuously improving the balloon mapping kit parts.

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yay switching out the swivels! Now i'm also interested in who has a good method of determining if the balloon is inflated enough. I do "arm's length" measuring, and also a sort of "thump" test.

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balloon diameter is a good method-- the balloon is pretty spherical. @jbreen marks the wall with measurements before inflating.

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Thumping sounds awesome. what note does the balloon make? at 1.3kg lift?

like, a tuner could measure that?

maybe put chalk in the kit?

the baggage scale that i use is good for physics lessons, but thumping or chalk sounds more like the public lab way

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I'm buying a bunch of these from McMaster to try out as a cable tie replacement in the kit. http://www.mcmaster.com/#6605k23/=u1tmx6

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It looks like McMaster sells them for $5-6 per pack of ten. Here are 50 ties for $6: http://www.amazon.com/dp/B000F5K82A/ref=pe_385040_30332200_TE_item# These ones are quite nice.

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@eustatic's straps had that cinch down bit that I like-- they're a little more, but those are also cheaper on Amazon. http://www.amazon.com/Black-Velcro-Cable-Ties-roll/dp/B004SIODTE/ref=sr_1_41?s=office-products&ie=UTF8&qid=1412718179&sr=1-41&keywords=velcro+ties

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The ones I linked to have the hole in one end that the other end can pass through.

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oh shoot I missed that. they looked like straight ties. thanks.

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